Fundamentals of Neurology: An Illustrated Guide

13. Painful Syndromes

Fundamentals

Painful Syndromes of the Head and Neck

Painful Syndromes of the Face

Painful Shoulder–Arm Syndromes (SAS)

Pain in the Trunk and Back

Leg Pain

Pseudoradicular Pain

Image  Fundamentals

Many conditions whose most prominent, or sole, symptom is pain lie within the neurologist's area of expertise. In this chapter, we will discuss painful syndromes by location: headache, shoulder–arm pain, pain in the trunk,and pain in the lower limb. The etiological differential diagnosis of a painful syndrome cannot be restricted to neurological conditions but must always include diseases of nonneurological origin.

The generation and perception of pain. Pain is a type of unpleasant sensation. In terms of pathophysiology, it arises when specialized sensory end organs are excited by certain mechanical, thermal, or chemical stimuli of a potentially damaging (“noxious”) nature. The pain-related (“nociceptive”) impulses are conducted centrally, mainly by way of thin, poorly myelinated fibers, through the posterior root and into the spinal cord. The nociceptive fibers cross the midline in the spinal cord at their level of entry. They then ascend in the spinothalamic tract to the thalamus and onward to higher centers in the brain, through which pain can be consciously felt (cf. p. 73). Biochemical factors also play an important role in pain perception. In the periphery, the intensity of pain is increased by a variety of biogenic amines, e. g., substance P. In the central nervous system, the intensity of pain is modulated by the production of opioid substances in certain areas of the brain. Finally, psychological factors—determined both by personality and by the sociocultural environment—affect the manner in which pain is experienced and processed.

General aspects of the clinical history in patients with pain. Many painful syndromes have their origin in the nervous system and many others, in which there is no evident dysfunction of the nervous system (e.g., most kinds of headache), are nonetheless traditionally evaluated and treated by neurologists. These facts justify the inclusion of painful syndromes in a textbook of neurology for medical students. It should be emphasized, however, that the physician must not merely analyze the symptom “pain” from the narrow viewpoint of his or her particular specialty, but must, rather, apply the full range of general medical knowledge.

This purpose is best served, first, by the taking of a systematic and directed pain history. Some important elements of the pain history are listed in Table 13.1. Further, specific questions will need to be asked depending on the nature and location of pain in the particular case and ancillary diagnostic tests may be necessary.

Table 13.1 Pain history

Where is the pain?

Image Precisely localized or diffuse?

Image Constant or varying localization?

Image Radiating?

How long has it been present?

Image For what length of time?

Image Since what precipitating event, if any?

Continuous or intermittent?

Image If continuous: of constant or variable intensity?

Image If intermittent: how long and how frequent are the episodes of pain?

Quality?

Image Hammering?

Image Throbbing?

Image Stabbing?

Image Dull?

Image Burning?

Intensity?

Image On a scale of 0 (no pain) to 10 (intolerable pain)

Precipitating and/or aggravating factors?

Image None?

Image Constant or variable factors—which, if any?

Image Dependence on posture?

Alleviating factors?

Image None?

Image Constant or variable factors—which, if any?

Image Medications—which ones, with what effect, lasting how long?

How severely is the patient impaired by the pain?

Image At work?

Image In the personal sphere?

Current complaints other than pain?

What is the patient's own explanation for the pain?

Other medical history?

Living situation?

In the remainder of this chapter, we will discuss various major painful syndromes, classifying them by location.

Image  Painful Syndromes of the Head And Neck

Headache can be either idiopathic or symptomatic. The most common idiopathic or “primary” types of headache are tension-type headache, migraine, and cluster headache. These three types of headache were once collectively designated “vasomotor headache.” While migraine and cluster headache are typified by highly characteristic, usually unilateral attacks of pain, tension-type headache more commonly assumes the form of a diffuse, continuous headache of lesser intensity. Symptomatic headaches are, by definition, a manifestation of some other underlying condition. The possible causes include many types of neurological disease, as well as diseases of the eyes, teeth, jaw, ear, nose, and throat. Spondylogenic headache is caused by pathological processes in the cervical spine.

Headache can also include a variably significant component of facial pain—a typical example is cluster headache, in which the pain is felt mainly in the forehead, eye, and temple. Headache and facial pain cannot be cleanly separated from each other and are therefore considered under one heading in the IHS classification (see below and also Table 13.2). Nonetheless, it is pedagogically useful, for the purpose of clarity, to distinguish syndromes in which the pain is mainly in the head from others in which the pain is mainly in the face. Facial pain will accordingly be discussed in the next section.

IHS Classification of Headache

The classification of headache syndromes proposed by the International Headache Society (IHS) has won general acceptance and is reproduced, in highly simplified form, in Table 13.2. The IHS has established a list of obligatory diagnostic criteria for each type of headache listed (in this book, we give the complete IHS criteria for migraine only; cf. p. 246). This highly precise approach to headache syndromes is most useful in clinical research, particularly when the results of different teams of investigators working in different countries are to be compared with each other. For example, the potential benefit of a method of treating a particular type headache can only be reliably assessed if it is definitely known that all of the research teams reporting on it are, in fact, treating the same condition. For the beginning student of neurology, however, it is more useful to gain a descriptive overview of the more common, “classic” types of headache. In particular, he or she should learn to distinguish the common idiopathic types of headache, i. e., those not due to any demonstrable structural lesion in the head, from symptomatic types. The latter are caused by organic disease of the cranial vessels or other structures in the head. 90% of all cases of headache are idiopathic.

Image

Image

Approach to the Patient with Headache

The patient who goes to the doctor because of headache is suffering from pain and, often, anxiety. He or she therefore expects

Image to be taken seriously,

Image to be examined carefully,

Image to have the cause of the problem identified and clearly explained.

The physician must take the time needed to meet these expectations fully.

The headache history. The clinical history is a vital step in the evaluation of headache (as of any other physical complaint). Some important points to be covered in the systematic interview of the headache patient are listed in Table 13.3. A carefully elicited history usually yields a clear-cut diagnosis. Nonetheless, the neurological and general physical examination (Table 13.4) should never be omitted, not least because these steps help the physician win the patient's confidence—an important factor for the success of treatment.

Migraine

Migraine, a type of idiopathic headache, is the second most common type of headache overall, after tensiontype headache (see below). Migraine without aura (formerly called simple or common migraine), whose sole neurological manifestation is headache, is distinguished from complicated migraine, in which additional neurological manifestations are present.

Table 13.3 Headache history

Image Family history of headache?

Image Medications and other counteractive measures:

Image How long have headaches been present?

Image frequency

Image Nature of headache:

Image dose

Image site?

Image efficacy

Image continuous or episodic?

Image Other symptoms besides headache:

Image usual or strange quality of pain?

Image ENT, eye, or dental disease?

Image timing of onset?

Image memory?

Image speed of development?

Image neurological/neuropsychological deficits?

Image nature of pain?

Image epileptic seizures?

Image precipitating factors?

Image general symptoms (fatigue, weight loss, circulatory problems, etc.)?

Image duration of episodes?

Image accompanying signs?

Image Personality:

Image Frequency?

Image character?

Image Headache-free intervals?

Image occupation?

Image Intensity, impairment of activities at home and at work?

Image private life?

 

Image conflicts?

 

Image alcohol, tobacco, caffeine, drugs of abuse?

 

Image medications?

Table 13.4 Examination of patients with headache

General medical examination

Neurological examination, with particular attention to:

blood pressure

meningism

circulatory function

signs of intracranial hypertension

renal function

focal neurological signs

signs of infection

cranial nerve deficits

signs of meningitis

 

signs of malignancy

Mental status, with particular attention to:

ENT diseases

psycho-organic syndrome

eye diseases

neuropsychological deficit

dental diseases, jaw diseases

impairment of consciousness

cervical spondylosis

psychological conflicts depression neurotic personality traits

Pathogenesis. Multiple factors contribute to the generation of a migraine attack:

Image Genetic factors play a role; in some patients, for example, there are well-documented ion channel abnormalities. Many patients report a history of migraine in their relatives, particularly on the maternal side.

Image Abnormal neural excitation in the diencephalon, particularly in the thalamic zone representing the trigeminal area, also plays a role in the pathogenesis of migraine. Events occurring in this nuclear area are responsible for the triggering of (unilateral) migraine attacks by peripheral stimuli or emotional factors.

Image The pathogenetic role of so-called “spreading depression” is unclear. This is a phenomenon, known from animal research, in which a stimulus delivered locally to the occipital cortex induces a wave of excitation that spreads toward the frontal lobe. The excitation is then followed by reduced excitability (“depression”). It is an established fact that the speed of this disturbance, as it moves from back to front, correlates precisely with the speed of a scintillating scotoma moving across the visual field in an attack of ophthalmic migraine.

Image Finally, a number of biochemical processes in peripheral blood vessels, modulated by the trigeminovascular reflex, are another contributing factor. These include the secretion of serotonin and histamine by platelets and mast cells. A rise in serotonin concentration initially induces contraction of the cerebral vessels. At the same time, serotonin and histamine act together to increase capillary permeability. Plasma kinins penetrate the vessel wall and lower the pain threshold in the periarterial tissue. The vessels then expand again and, at the moment of vasodilation, the typical throbbing pain begins. Different types of serotonin receptors in the periphery and in the brain play a role in the generation of migraine. Many of the modern pharmacologic treatments for migraine exert their effects by influencing these processes (see below).

Migraine without Aura

An attack of simple (common) migraine develops without any premonitory symptoms (aura) and is characterized by headache and accompanying autonomic manifestations. About 70% of all migraine attacks are of this type.

Epidemiology. Women suffer from migraine more commonly than men. The initial attacks usually occur in the first or second decade of life; about 5% of all schoolchildren already suffer from true migraine. The overall prevalence of migraine in the population is estimated at 10%.

Clinical manifestations. The headache is unilateral (hemicranial) in two-thirds of patients and is usually located in the temporal and parietal areas. (The word “migraine” comes from the Latin “hemicrania.”) In most patients, the attacks tend to affect one side much more often than the other, though contralateral headaches do sometimes occur. The pain occasionally migrates from one side to the other during an attack; it is primarily bilateral in about one third of all attacks. It rises to a maximum in one hour or a few hours and then generally persists for many hours after that. The quality of the pain is usually described as pulsating and throbbing; it worsens with any kind of physical exertion, even as mild as climbing a staircase. Accompanying symptoms are usually present: 60% of patients complain of nausea, anorexia, and intolerance of light, sound, and (frequently) odors. Patients are often irritable and in a bad mood during the attack. The objective findings may include pallor, diaphoresis (common), and sometimes tachycardia, vomiting, and/or diarrhea. The frequency of attacks varies from a few per year to several per week. The frequency and intensity of attacks determine the degree to which migraine affects the individual patient in his or her everyday activities; the impairment may be severe.

Image

Fig. 13.1 Migraine attack: schematic diagram.

IHS criteria. The IHS has promulgated the following defining criteria for simple migraine:

Image A: At least five episodes fulfilling criteria B through D, below.

Image B: The headache episodes last four to 72 hours (or, in children under 15 years of age, two to 48 hours), either when untreated or when treated unsuccessfully.

Image C: The headache has at least two of the following features:

Image 1. unilateral localization,

Image 2. pulsating character,

Image 3. moderate or marked intensity (makes everyday activities difficult or impossible),

Image 4. exacerbation by climbing stairs or other habitual physical activities.

Image D: At least one of the following symptoms is presentduring the headache:

Image 1. nausea and/or vomiting,

Image 2. abnormal sensitivity to light and noise.

The typical features of a migraine attack are shown schematically in Fig. 13.1.

Treatment. The treatment of common migraine depends on the frequency and severity of the attacks. If the attacks are rare and mild, treatment is generally not necessary.

Headaches of intermediate severity, not very prolonged duration, and low frequency (less than once per week) can be managed by treating the individual attacks with analgesic medications in adequately high doses in the early stages of each attack, e.g., 1000 mg of acetylsalicylic acid. An antiemetic should be prescribed as well, e.g., 20mg of metoclopramide, by mouth or, if necessary, as a suppository. If these measures do not adequately treat the headache, triptanes are given by mouth, or, if necessary, as a nasal spray or by injection. Some patients obtain relief with ergotamines.

If the attacks occur more than once per week and/or severely hamper the patient's everyday activities by their severity or duration, attack prophylaxis can be initiated. Once begun, this must usually be maintained continuously for months or years afterward. Medications for attack prophylaxis include the beta-blocker propranolol and the tricyclic antidepressant amitriptyline, as well as valproate, dihydroergotamine, and flunarizine.

These recommendations also apply to the various types of complicated migraine described below.

Types of Complicated Migraine

About one-third of all persons with migraine have additional neurological manifestations besides the headache itself, e. g., visual disturbances, paralysis, sensory abnormalities, vertigo, or abdominal or cardiac symptoms. These manifestations may be very dramatic, sometimes overshadowing the headache to such an extent that the patient's illness is not immediately recognizable as migraine. We will now describe the major types of complicated migraine individually.

Image

Fig. 13.2 Scintillating scotoma during an attack of ophthalmic migraine: typical fortification figures.

Table 13.5 Manifestations of basilar migraine (according to frequency), after Sturzenegger and Meienberg

Bilateral visual disturbance

Image scintillating scotoma or elementary hallucinations

Image diffuse loss of visual acuity

Image transient amaurosis

Image visual field defects

Image dysmorphopsias

Nausea

Impairments of consciousness

Image syncope

Image confusion

Image stupor

Image amnesia

Image coma

Paresthesiae (bilateral)

Vomiting

Dizziness

Gait ataxia

Dysarthria

Limb weakness

Ophthalmic migraine, the most common and probably best-known type of migraine, is often called “classic migraine” in the English-speaking world. (Note: clinicians in other parts of the world call simplemigraine “classic migraine,” so we will avoid confusion here by not using the term any further.) A scintillating scotoma appears 10 to 20 minutes before the headache. It begins in the center of the visual field, impairing the patient's ability to read (for example). A bright, zigzag line then travels from the center of the visual field outward in one-half of the visual field, until it “falls off the visual field” at the periphery, leaving behind a transient blurriness of vision in the corresponding hemifield. A typical scintillating scotoma or “fortification specter” (think of a crenellated medieval fortress) is shown in the diagram in Fig. 13.2. The scintillating scotoma is usually followed by an attack of hemicranial headache. Occasionally, a scintillating scotoma may occur without subsequent headache; such events are called “migraine sans migraine.” So-called retinal migraine is a very rare variant involving a vertically demarcated scintillating scotoma or a monocular visual disturbance lasting a few minutes.

Migraine accompagnee is characterized by the combination of headache with hemiparesis, a hemisensory deficit, or some other type of focal neurological or neuropsychological deficit. This variant of migraine usually has its onset in childhood or adolescence. In each attack, the affected individual progressively develops, for example, weakness or numbness and paresthesia on one half of the body, over the course of a few minutes. When the migrainous process is located in the left hemisphere, the patient can often become aphasic as well. The hemiparesis is never complete (i. e., never a hemiplegia) and the patient remains conscious. The headache usually comes after the neurological disturbances, but may also accompany or precede them, and it may be on the same or the opposite side. All manifestations resolve within a few hours, or in one or two days at most. Low-grade CSF pleocytosis and a focus of δ-activity in the EEG can often be demonstrated during an attack. SPECT, too, reveals focal changes. If there is no headache, one speaks of “migraine sans migraine” here as well (just as in ophthalmic migraine without headache). With regard to differential diagnosis, an attack of migraine accompagnée can usually be distinguished from an acute ischemic stroke by the slow development of the neurological deficit and by the accompanying headache. In patients without headache, however, this distinction is not always easy to make, particularly in a first attack, and a thorough diagnostic evaluation is required.

Basilar migraine. In this type of migraine, the pathological process takes place in the structures of the posterior fossa. Basilar migraine mainly affects girls and young women. Its main manifestations are listed in Table 13.5: visual disturbances, symmetrical paresthesiae in the perioral region and the limbs, and impairment of consciousness. The accompanying headache is commonly felt at the back of the head.

Other types. Two special types of migraine deserve mention. Familial hemiplegic migraine, caused by a hereditary disease of ion channels, generally appears in childhood and may be accompanied by cerebellar ataxia. Rarely, an attack of this type of migraine can be followed by a permanent neurological deficit. The rare alternating migraine of childhood begins in the first year of life and is associated with progressive psychomotor retardation. Attacks of hemiparesis on alternating sides of the body last from a quarter of an hour to several hours or even days. There may also be dystonic movements, nystagmus, or tonic crises. Naloxone and flunarizine are effective in treating this disorder.

Cluster Headache

Alternative names for this disorder include “Bing–Hor-ton neuralgia” and “erythroprosopalgia.”

Image

Fig. 13.3 Cluster headache: schematic diagram of an attack.

Etiology and pathogenesis. The appearance of cluster headache attacks in a circadian rhythm seems to imply that this disorder is due to a functional disturbance of the diencephalon. It shares a number of pathophysiological and biochemical features with migraine. In addition to idiopathic cluster headache, there are also symptomatic forms, caused, e.g., by mass lesions.

Clinical manifestations. These are highly typical and are illustrated in Fig. 13.3.

Image The headache attacks always occur on the same side of the head. The pain is mainly felt in the temple, eye, and forehead.

Image The pain reaches its maximum in 10–20 minutes. Each attack lasts from half an hour to two hours; attacks may occur “on schedule” at the same time of day every day (during a cluster), particularly at night.

Image A number of attacks can occur “in series” in a 24-hour period.

Image The pain is very intense, often pulsating and throbbing. The patient is agitated and paces around restlessly.

Image Attacks are usually accompanied by the following objective findings:

Image Horner syndrome of the ipsilateral eye.

Image A red, teary eye and periorbital erythema.

Image A stuffed nose and/or increased nasal secretion.

Image The attacks appear during periods called “clusters,” lasting weeks or months; the clusters alternate withattackfree intervals lasting months or years.

Besides the episodic form just described, there is also a chronic form of cluster headache, in which the headache attacks occur every day and there are no attack-free intervals. It is not uncommon for typical migraine to be replaced by typical cluster headache (or vice versa) at some point in a patient's life. Many patients, too, have headaches bearing some of the features of both migraine and cluster headache.

Image

Fig. 13.4 Cluster headache, left-sided attack in a 45-year-old man. The left palpebral fissure is narrowed, and the conjunctiva and periorbital area are erythematous.

Diagnostic evaluation. The acute attacks, because they are brief, are only rarely observed by the physician. The diagnosis thus depends on a precise clinical history (as it does in nearly all types of headache). A physician who has the good fortune to observe the patient during an attack will likely see the characteristic appearance shown in Fig. 13.4.

Treatment. Treatment of an acute attack is difficult. Triptanes can be given by subcutaneous injection, or the patient can be given pure oxygen to breathe (7 liters per minute for 15 minutes). Medications for the reduction of attack frequency include verapamil and indomethacin, sometimes in combination with a tricyclic antidepressant. A brief course of cortisone treatment is often effective. The chronic form responds to lithium.

Tension-type Headache

This is probably the most common type of headache. It was previously known as “vasomotor headache.” Its clinical features resemble those of postconcussive headache.

Table 13.6 Some rare types of primary headache

Type

Clinical features

Remarks

Hemicrania continua

persistent unilateral headache

responds to indomethacin and perhaps to ASA

“Ice-cream headache”

acute headache, usually temporal, lasting 20–30 seconds, precipitated by a cold stimulus on the palate (such as ice cream)

 

Cough headache

precipitated by coughing, abdominal straining, or bending over; an intense, diffuse headache lasting a few seconds

usually innocuous, but sometimes due to a pathological process in the posterior cranial fossa

Coital headache

sudden onset, lasts minutes or hours, sometimes accompanied by vomiting

no meningismus (differential diagnosis: subarachnoid hemorrhage!)

Etiology. The cause of tensiontype headache is unknown. It is no longer thought to be due to muscle tension. A current hypothesis attributes it to abnormal sensitivity to pain in the trigeminal nuclear complex. This complex, in turn, receives input from other structures in the brain, including the limbic system.

Clinical manifestations. Patients complain of a pressing, aching pain in the head, which is usually diffuse, i. e., there is no particular location at which it is most intense. It is of no more than intermediate severity and does not worsen with physical activity. It is not associated with nausea, photophobia, or phonophobia, and usually does not keep patients from going about their everyday activities.

There are episodic and chronic forms of tension-type headache. Patients with the episodic form suffer from headache on fewer than 15 days per month (180 days per year). The individual episodes of headache may last from 30 minutes to several days. Patients with the chronic form suffer from headache on more than 15 days per month (180 days per year).

Diagnostic evaluation. The history is crucial, as the neurological examination and ancillary tests do not reveal any abnormalities.

Treatment. Life-style readjustment is the recommended first line of therapy: removal of headache-producing substances such as alcohol and nicotine, regular physical exercise, regular sleep, stress reduction, and, if necessary, other changes in the patient's living situation and mode of living. If medications are needed, tricyclic antidepressants are the agents of choice, followed by beta-blockers or tizanidine.

Rare Varieties of Primary headache

Table 13.6 provides an overview of rarer types of primary headache other than migraine, cluster headache, and tension-type headache.

Symptomatic Headache

Symptomatic headache is due to a structural lesion, infection, or inflammation of intra- and/or extracranial tissue. Its direct cause is often a pathological alteration of intracranial pressure, which excites nociceptive nerve endings in the meninges. The ICP may be either too high (particularly because of space-occupying lesions such as hematomas, tumors, and hydrocephalus) or too low (e.g., in the intracranial hypotension syndrome after a lumbar puncture).

Symptomatic headache, however, is not necessarily due to neurological disease. Pathological conditions of the ears, nose, throat, eyes, teeth, or jaw can also cause head and/or facial pain, which may be quite severe. Even diseases of the cervical spine can, rarely, produce headache (spondylogenic headache).

Table 13.7 provides an overview of the major causes of symptomatic headache. We will describe a few of the causative neurological illnesses and spondylogenic headache, in detail in the following paragraphs.

Occlusions and Dissections of Cranial Vessels

Arterial occlusion only rarely causes headache, but, if it does, the site of the headache may be a clue to the identity of the occluded vessel: occlusion of the internal carotid a. produces temporal headache, while occlusion of the basilar a. produces headache in a ringlike distribution around the head. Very intense pain on one side of the neck and face accompanies acute dissection of the internal carotid a. Vertebral artery dissection produces pain in the ipsilateral occiput and nuchal region. Dissections can arise spontaneously or after trauma to the head or neck.

Intracranial Hemorrhage

Subarachnoid hemorrhage (SAH) due to a ruptured saccular aneurysm at the base of the brain produces an extremely intense, diffuse headache of lightning-like onset (“the worst headache of my life”), possibly accompanied by meningismus and an impairment of consciousness. If the patient is comatose, of course, the headache and meningismus may be masked or absent. Intracerebral hemorrhage (e.g., spontaneous hemorrhage due to hydrocephalus, into a tumor, or from a ruptured arteriovenous malformation) causes rapidly progressive headache in addition to hemiparesis and progressive impairment of consciousness. A more slowly progressive headache, perhaps accompanied by a fluctuating level of consciousness, is typical of chronic subdural hematoma. Neurological deficits in these patients are surprisingly rare (p. 91).

Cranial Arteritis

Cranial (also called temporal) arteritis is an autoimmune disease of blood vessels that almost exclusively affects persons over age 60. Its most prominent, though by no means only, clinical manifestations are in the large and middle-sized extracranial arteries.

Image

Clinical manifestations. The leading symptom is an atypical headache that rapidly worsens over a few days or weeks and then becomes constant, often in the temporal region. The affected arteries (particularly the superficial temporal a.) are tender, tortuous, and swollen (Fig. 13.5). They may occlude by thrombosis, in which case they cease to pulsate. The headache is often accompanied by further manifestations: pain in the shoulder and pelvic girdle muscles, fatigue, subfebrile temperature, weight loss, and nocturnal diaphoresis—a systemic syndrome known as polymyalgia rheumatica. The complication to be most feared is involvement of the ophthalmic a. causing occlusion of the central retinal a. and sudden blindness (Fig. 13.6).

Image

Fig. 13.5 Temporal arteritis in a 65-year-old man. Note the thickened, painful, no longer pulsating superficial temporal a.

Image

Fig. 13.6 Atrophic optic disc in a 79-year-old woman with temporal arteritis. Note the abnormal disc pallor; the patient is blind in this eye.

Table 13.8 Diagnostic criteria for spondylogenic headache

Characteristics of pain

Image radiating from occipital to frontal

Image usually unilateral

Image coming in attacks, or

Image permanent pain of variable intensity

Image not throbbing

Image moderately severe

Cervical spine

Image prior history of trauma to the head or cervical spine

Image or prior whiplash injury

Image or episodes of torticollis (wry neck),

Image perhaps accompanied by arm pain

Image clinical or radiological evidence of cervical spine pathology

Precipitating and alleviating factors

Image pain induced by movement (or manipulation) of the cervical spine

Image or by keeping the head in a particular position for a longer than usual time

Image or by local pressure on the nape of the neck or the occiput

Image pain temporarily alleviated by infiltration of the greater occipital n. or the C2 nerve root with local anaesthetic

Accompanying symptoms

Image dizziness

Image nausea

Image blurred vision

Image phono- and photophobia

Image dysphagia

Image  Painful Syndromes of the Face

Facial pain is often due to a lesion of a sensory nerve in the face, most commonly the trigeminal n. It typically presents with very brief, but very intense attacks of pain (“classic” or “genuine” neuralgia in the face). There are also a variety of other kinds of facial pain with other pathogenetic mechanisms, e.g., a structural anomaly of the jaw. The pain may resemble neuralgia in these other conditions as well; thus, patients with any kind of facial pain always require careful evaluation to establish the differential diagnosis.

Diagnostic evaluation. The erythrocyte sedimentation rate is nearly always markedly elevated. The diagnosis is confirmed by temporal artery biopsy: histopathological examination reveals giant cell arteritis. A biopsy should be performed in all suspected cases, because there is no other way to establish the diagnosis with the certainty required before starting long-term treatment with corticosteroids. These often need to be given continuously for a year or more.

Spondylogenic Headache (“Migraine Cervicale”)

Our experience suggests that this condition is overdiag-nosed. The appropriate diagnostic criteria to be used are summarized in Table 13.8.

Dangerous Types of Headache

All patients who consult a physician because of headache are in pain and therefore deserve our full attention and respect. More than 90% of them, however, will turn out not to have a serious medical problem. One of the important tasks facing the physician is to be on guard for those few, unusual cases of headache that are, in fact, due to a dangerous underlying condition. The main alarm signals are the following:

Image headache of an unusual nature in a patient who never had headaches before;

Image headache arising at an advanced age;

Image headache of sudden (lightning-like) onset;

Image headache that always occurs in precisely the same location (except cluster headache or trigeminal neuralgia, both of which, by definition, always occur in the same place);

Image progressively severe headache (crescendo headache);

Image continuous headache;

Image headache accompanied by:

Image personality change,

Image impairment of consciousness,

Image epileptic seizures;

Image neurological deficits revealed on physical examination.

If any of the above applies, further investigation is needed, usually with an imaging study.

“Genuine” Neuralgias in the Face

Typical manifestations of “genuine” neuralgia in the face are the following:

Image pain is located in the face or the mucous membranes of the head,

Image usually comes in brief attacks lasting a few seconds to a few minutes at most,

Image is usually very intense;

Image is described as electrical, knifelike, cutting, stabbing, or lightninglike;

Image arises either spontaneously or on provocation by touch or other mechanical or thermal stimuli;

Image is always on the same side of the face (in most patients);

Image and is always in the same location.

Image In addition, the attacks are very frequent, up to several times a day,

Image with no pain in between attacks, except, possibly, for a dull background pain.

Image Finally, there are no objective neurological abnormalities, except in the rare forms of symptomatic neuralgia.

The most common “genuine” neuralgias in the face are described in the following paragraphs. The localization and radiation of pain in the various types of neuralgia are depicted in Fig. 13.7.

Trigeminal Neuralgia

Idiopathic trigeminal neuralgia, which is far more common than the symptomatic type, only affects individuals over age 50.

Pathogenesis. Idiopathic trigeminal neuralgia appears to have more than one possible cause. In many patients, neuroimaging studies reveal a looping blood vessel that makes contact with the trigeminal n. at its zone of entry into the pons. In other patients, defective myelin sheaths are found in the Gasserian ganglion (naturally only at postmortem examination). In symptomatic trigeminal neuralgia, on the other hand, the pain is due to an underlying neurological disease, e.g., multiple sclerosis.

Clinical manifestations. The painful attacks of idiopathic trigeminal neuralgia are usually located in the distribution of the second trigeminal division (the maxillary n.), less commonly in that of the first or third divisions. The pain is nearly always unilateral; it is felt on both sides simultaneously, or in alternation, in only 3% of patients. The individual attacks last only a few seconds and cause a reflexive grimace or pulling of the face (“tic douloureux” not to be confused with a tic in the usual sense of a primary movement disorder). The pain is unbearably intense. The attacks occur spontaneously or on provocation by eating, speaking, tooth brushing, or touch; they may come dozens of times per day. Some patients eat and speak so little to avoid the pain that they lose weight, even to the point of cachexia. Attacks generally do not occur during sleep. The typical clinical manifestations of trigeminal neuralgia are depicted in Fig. 13.8. Sometimes, a long period with frequent attacks is followed by a pain-free interval that may last for months until the attacks return.

Image

Fig. 13.7 Localization of various types of facial pain and neuralgia. 1 Trigeminal neuralgia in the distribution of the maxillary nerve (V2). 2 Trigeminal neuralgia in the distribution of the mandibular nerve (V3). 3 Auriculotemporal neuralgia. 4 Nasociliary neuralgia. 5 Sluder's neuralgia. 6Glossopharyngeal neuralgia. 7 Neuralgia of the geniculate ganglion. 8 Temporomandibular joint “neuralgia” (myofacial pain syndrome).

Image

Fig. 13.8 Trigeminal neuralgia: schematic diagram.

In the rarer symptomatic cases of trigeminal neuralgia, the clinical manifestations are slightly different. The attacks are more commonly bilateral (either simultaneously or in alternation) and a neurological deficit may be found, depending on the underlying etiology, e.g., multiple sclerosis or a tumor compressing the trigeminal n.

Diagnostic evaluation. As stated above, the neurological examination generally reveals no abnormality. About one-quarter of patients who have suffered from idiopathic trigeminal neuralgia for a long time have a mild sensory deficit in the affected area of the face.

Treatment. About 80% of patients initially respond to correctly dosed treatment with carbamazepine or gabapentin. The medication must be taken every day and the dose must be steadily increased until the pain is relieved.

Image The pharmacological treatment of trigeminal neuralgia often fails because of underdosing or irregular consumption of the prescribed drug.

If pharmacological treatment does not eliminate the pain despite a high dose of medication (in some patients, just below the threshold for intolerable side effects, which varies greatly from one patient to the next), neurosurgical treatment is indicated. The available, effective procedures include open microvascular decompression of the trigeminal n. (requires craniotomy) and percutaneous techniques such as selective radio-frequency coagulation of the Gasserian ganglion, balloon compression of the ganglion, and glycerol injection into Meckel's cave.

Auriculotemporal Neuralgia

In this disorder, the pain is located in the temple and in front of the ear. It is usually a sequela of disease of the ipsilateral parotid gland, appearing a few days or months after the parotid condition resolves.

The attacks of pain can be provoked by chewing or by chemical stimuli, particularly sour (acidic) food. The pain is of a burning quality. It is often accompanied by erythema and increased sweating in the preauricular area.

The differential diagnosis of this condition includes temporomandibular joint syndrome.

Nasociliary Neuralgia

The attacks of pain are located in the nose and on the inner canthus of the eye. There may be a continuous, background pain in addition to the typical, lightninglike, shooting pain. In this condition, as in the other neuralgias of the face, the pain is provoked by chewing or by touch—here, by touching the eye. The attacks are often accompanied by redness of the eye, swelling of the nasal mucosa, and lacrimation. They can often be aborted by the application of a 5% cocaine solution inside the nostril. This condition is sometimes difficult to distinguish from cluster headache (p. 248). On rare occasions, it is also confused with dissection of the internal carotid a., which produces a similar type of pain.

Sluder Neuralgia

This condition is thought to be due to a pathological process affecting the pterygopalatine ganglion. Its clinical manifestations closely resemble those of nasociliary neuralgia (see above). In many patients, the attacks are accompanied by the urge to sneeze. Sluder neuralgia is occasionally associated with sphenoid or ethmoid sinusitis.

Glossopharyngeal Neuralgia

This condition is usually seen in the elderly. Its typical manifestations are lightninglike pain in the base of the tongue, the hypopharynx, and the tonsillar fossa, radiating toward the ear. The pain can be provoked by swallowing (especially of cold liquids), speaking, or sticking out the tongue. The painful attacks are, on rare occasions, accompanied by syncope. The pharmacological treatment of this disorder is like that of trigeminal neuralgia. If surgical treatment is required, resection of the glossopharyngeal n. and the upper root of the vagus n. has a good chance of success.

Rarer Types of Neuralgia

The neuralgias of the geniculate ganglion, the superior laryngeal n., and the auricular branch of the vagus n. are all very rare. The existence of occipital neuralgia is still debated.

Other Diseases Causing Facial Pain

Temporomandibular Joint Syndrome

This condition has many other names, including myofacial syndrome and Costen syndrome. Our experience suggests that it is overdiagnosed.

Pathogenesis. This condition is thought to be due to abnormal mechanical stress on the jaw joint caused by malocclusion, e.g., after tooth extraction, or by local changes in the joint itself. This, in turn, causes the muscles of mastication to be activated in nonphysiological ways, which leads to pain in the muscles, so that their pattern of activation is distorted even further. A vicious circle arises in which pain produces more pain.

Clinical manifestations. Patients typically suffer from more or less continuous preauricular pain, which is described as dull or neuralgia-like. The pain can be brought on, or made worse, by chewing.

Diagnostic evaluation. The jaw joint is tender to pressure on one or both sides. CT or MRI occasionally demonstrates an abnormality of the joint.

Treatment. Optimization of the dental occlusion (bite) sometimes relieves the pain to some extent. Unfortunately, however, many dental and surgical procedures on the teeth and jaws are performed for this condition to no avail.

Atypical Facial Pain

This term refers to unilateral, diffuse pain in the face. The pain is often of a burning or dull character and is maddeningly persistent. The condition generally affects middle-aged women. It may be of spontaneous onset, but, in many patients, the pain first appears (or becomes severe) in the aftermath of a dental procedure. This often leads to a series of further dental procedures, which the dentist or oral surgeon characteristically performs only after being urgently entreated to do so by the patient. Atypical facial pain is difficult to treat; perhaps the most important aspect of treatment is the avoidance of further surgery. Serotonin reuptake inhibitors, flunarizine, or tricyclic antidepressants have been used for this condition.

Glossodynia is a rare type of atypical facial pain consisting of dysesthesia of the tongue, often of a burning character. It usually affects elderly women.

General Differential Diagnosis of Headache and Facial Pain

The location and clinical course of headache and facial pain often provide important clues to its etiology. Important aspects of differential diagnosis are summarized in Table 13.9.

Table 13.9 Differential diagnosis of headache and facial pain

Clinical features

Syndrome

Recurrent attacks of intense headache with pain-free intervals

Image migraine (unilateral headache)

 

Image cluster headache (unilateral pain in the temporal region, eye, and face)

 

Image hypertensive crises (diffuse pain)

Recurrent attacks of intense facial pain with pain-free intervals

Image trigeminal neuralgia (duration, seconds; localization, usually mid-face)

 

Image auriculotemporal neuralgia (duration, minutes; localization, preauricular)

 

Image nasociliary neuralgia (duration, minutes to hours; localization, inner canthus)

 

Image Sluder neuralgia (duration, minutes; localization, inner canthus)

 

Image glossopharyngeal neuralgia (duration, seconds; localization, base of tongue and tonsillar fossa)

 

Image geniculate ganglion neuralgia (duration, seconds; localization, external auditory canal and palatal roof)

Continuous facial pain

Image atypical facial pain (diffuse, usually unilateral pain)

 

Image temporomandibular joint (TMJ) syndrome (preauricular)

Intense headache of sudden onset, which then persists

Image subarachnoid hemorrhage

 

Image intracerebral hemorrhage

Diffuse, usually intense headache of subacute onset, which then persists

Image meningitis, encephalitis (accompanied by meningism)

Headache on standing or sitting that improves when the patient lies down

Image intracranial hypotension

Chronic, or chronically relapsing, diffuse headache of insidious onset and mild to moderate severity

Image tension-type headache

 

Image headache due to hypertension

 

Image headache due to intracranial mass

 

Image posttraumatic headache

 

Image headache due to systemic illness (particularly febrile illness); toxic/iatrogenic headache; psychogenic or depressive headache

Chronic, localized headache and facial pain

Image spondylogenic headache (pain mainly in the back of the head)

 

Image cranial (temporal) arteritis (pain mainly temporal)

 

Image eye diseases (pain mainly frontal)

 

Image ENT diseases (esp. sinusitis, pain mainly frontal, worse on forward bending of the head)

 

Image odontogenic headache (jaw and temporal region)

Image  Painful Shoulder–Arm Syndromes (SAS)

Pain in the shoulder and arm is a common complaint. The differential diagnosis includes conditions belonging to widely disparate medical specialties: cervical spine pathology (spondylogenic arm pain); degenerative changesof the joints of the shoulder and upper limb and the adjacent connective tissues (ligaments, tendons, joint capsules); diseases of the cervical nerve roots, brachial plexus, and peripheral nerves (neurogenic arm pain); and vascular diseases. Finally, there remains “arm pain of overuse,” a collection of conditions due to nonphysiological stress on the muscles and joints of the upper limb.

An overview of diseases producing pain in the shoulder and arm is provided in Table 13.10. The clinical features of the more common conditions of this type are described in the following paragraphs.

Table 13.10 Overview of shoulder–arm pain

Category

Etiology

Remarks

Spondylogenic pain

Image spondylosis

Image nuchal pain at first; pain radiation is often diffuse

 

Image disk herniation

Image acute torticollis at first, only later followed by pain radiation in a radicular pattern; demonstrable neurological deficits

Nonspondylogenic nerve root lesion

Image tumor

Image slowly progressive symptoms

 

Image dissection of the vertebral a.

Image acute, unilateral nuchal or occipital pain

Brachial plexus lesion

Image tumor

Image e. g., lung apex tumor with lower brachial plexus involvement and Horner syndrome

 

Image radiation injury

Image pain and progressive neurological deficits after a latency period

 

Image neuralgic shoulder amyotrophy

Image intense pain for one or more days, followed by weakness of shoulder girdle or arm muscles

 

Image thoracic outlet syndrome (TOS)

Image overdiagnosed; the diagnosis can be accepted if there is a cervical rib or other anomaly of the thoracic outlet

 

Image hyperabduction syndrome

Image the arm “falls asleep” at night in certain positions

 

Image posttraumatic brachial plexus dysfunction

Image phantom pain, neuroma pain, stump pain

Lesion of an individual peripheral nerve (or branch)

Image radial n.

Image supinator syndrome

 

Image median n.

Image pronator syndrome, carpal tunnel syndrome (most common cause of nocturnal arm pain)

 

Image ulnar n.

Image sulcus ulnaris syndrome

 

Image cutaneous sensory branches

Image e. g., elbow after paravenous injection

Rheumatologic disorders

Image in the shoulder region

Image rotator cuff involvement, impingement syndrome

 

Image in the elbow region

Image radial epicondylitis (tennis elbow), ulnar epicondylitis (golfer's elbow)

 

Image in the distal forearm and hand

Image radial styloiditis, metacarpophalangeal joint of the thumb, e. g., in gout

Brachialgia of vascular origin

Image arterial

Image acute brachial a. occlusion, subclavian steal syndrome

 

Image venous

Image effort thrombosis

Tenomyalgic and pseudoradicular overuse syndromes

Image diffuse brachialgia after nonphysiological overuse of an arm, or secondary to weakness of the shoulder muscles

Image various professions, e. g., bank teller, or in the wake of trapezius weakness

Rarer causes

Image glomus tumor

Image a locally painful blue spot is often visible under the fingernail; the pain increases when the arm is dependent

Spondylogenic (Cervicogenic) Shoulder and Arm Pain

Etiology. The cause is usually degenerative osteochondrosis producing spondylotic narrowing of the intervertebral foramina; sometimes, cervical disk herniation is also present. These disease processes compress and mechanically irritate the cervical nerve roots.

Clinical manifestations. Conditions of this type always begin with neck pain and/or a painful restriction of head movement. Later on, the pain radiates into the shoulder and usually down the arm (cervicobrachialgia). The pain is diffuse in some patients, but often remains mostly within the dermatome of the affected nerve root (i. e., radicular pain): thus, C6 lesions cause pain on the lateral aspect of the forearm and the thumb region, C7 lesions cause pain in the middle finger, and C8 lesions cause pain on the ulnar side of the hand and in the fourth and fifth fingers (cf. p. 208). The objective findingsinclude painful restriction of head movement and, sometimes, radicular neurological deficits—weakness, loss of reflexes, and diminished sensation in the distribution of the affected nerve root (cf. Table 12.1p. 208).

Treatment. Physical therapy and analgesic medications are the mainstays of treatment (cf. p. 211).

Degenerative and Rheumatic Shoulder and Arm Pain

Most cases of pain in the shoulder and arm are probably caused by degenerative changes of the bones, joints, tendons, and other soft tissues.

Degenerative disease of the rotator cuff. This painful syndrome, formerly termed humeroscapular periarthropathy, arises after shoulder trauma (a blow or sprain) or immobilization. The tendons of the short rotators of the shoulder joint undergo degenerative changes, sometimes with calcium deposition, and these changes lead to irritation of the subdeltoid bursa. The highly typical clinical finding is local shoulder pain on active raising of the arm, particularly with simultaneous internal rotation. It is painful, for example, for the patient to slip the arm into a sleeve while getting dressed. If the abducted arm is then rested on a surface (table, etc.), the pain disappears. The diseased tendon(s) is (are) tender to palpation, usually ventral to the shoulder joint. Plain radiographs may reveal calcifications. Rotator cuff tear produces mechanical weakness of abduction, objectively demonstrable as the so-called “lag sign.”

Impingement syndrome is closely related to degenerative disease of the rotator cuff. In this condition, when the arm is abducted, the painful area of the rotator cuff comes into contact with the coracoacromial roof.

Frozen shoulder syndrome sometimes represents the end stage of degenerative disease of the rotator cuff, but more commonly arises as a sequela of hemiparesis or myocardial infarction. It is also rarely caused by phenobarbital use. It is characterized by very painful restriction of shoulder movement, with a slowly progressive course.

Regional pain syndrome. This often-intractable condition used to be known as reflex sympathetic dystrophy, algodystrophy, or Sudeck dystrophy. The sympathetic nervous system plays an important role in its pathogenesis, particularly as a cause of the characteristic swelling. Faulty information processing in the neurons of the dorsal horn of the spinal cord is thought to be another contributing factor. Regional pain syndrome can affect any part of the upper or lower limbs, but it is particularly common in the hand. It tends to arise after a fracture or other type of trauma, which need not be particularly severe. The clinical findings include soft tissue swelling, smooth, cool, often cyanotic skin, and a very painful restriction of joint mobility. Plain radiographs reveal patchy osteoporosis of the bones in the affected area.

Epicondylitis is characterized by pain at the origins of the extensor and flexor muscles of the hand and fingers on the humeral epicondyles. The pain can be felt spontaneously, on movement of the affected tendons and muscles, or in response to local pressure. The usual cause is muscle overuse. The commonest type is lateral epicondylitis, so-called “tennis elbow.” Medial epicondylitis (“golfer's elbow”) is rarer and is caused by overuse of the flexor muscles.

Styloiditis. Radial styloiditis is characterized by pain at the tendinous origins of the extensor carpi radialis muscles on the styloid process of the radius; ulnar styloiditis is the analogous condition on the styloid process of the ulna. Both of these conditions are varieties of tendinitis, similar to other varieties occurring elsewhere in the body.

Neurogenic Arm Pain

In these conditions, pain in the arm and shoulder is due to a lesion affecting sensory nerve fibers, either in the brachial plexus or in the peripheral nerves. The lesion may be either mechanical (common) or infectious/inflammatory(less common).

Irritation of the Brachial Plexus

Compression of the brachial plexus at the thoracic outlet can occur at any of several anatomical bottlenecks (the scalene hiatus, the costoclavicular passage, or the subacromial space). This generally occurs, however, only when an additional pathogenic factor is present, such as a cervical rib, fibrous band, anomaly of the scalene attachments, or excessive exogenous pressure. The corresponding clinical syndromes are discussed in Chapter 12 (p. 220).

Brachial plexus tumors sometimes cause progressively worsening arm pain that becomes very severe within a matter of weeks. Pancoast tumors of the lung apex are a well-known cause (p. 222).

Neuralgic shoulder amyotrophy (p. 222) also causes acute, severe pain.

Peripheral Nerve Conditions

Compressive neuropathies can cause severe, intractable pain in the upper limb. These conditions are described in Chapter 12. The more common types are sulcus ulnaris syndrome (p. 232) and carpal tunnel syndrome (p. 228), which causes arm pain especially at night (brachialgia paraesthetica nocturna).

Vasogenic Arm Pain

Arterial Diseases

Occlusion or stenosis of the subclavian a. causes diffuse arm pain on movement, forcing the patient to stop using the limb (“intermittent claudication of the arm”). If the artery is occluded proximal to the origin of the vertebral a., the arm will be supplied with blood through retrograde flow in the vertebral a. Blood can be “stolen” in this way from the cerebral circulation (subclavian steal syndrome): movement of the arm diverts blood flow away from the vertebrobasilar territory in the brain and lightheadedness or sudden falls (drop attacks) may result. Arterial insufficiency in the upper limb is demonstrated with the fist-clenching test: the patient holds the upper limbs high, then rapidly and repeatedly clenches and reopens both hands. Pain arises within a few minutes on the poorly perfused side and the hand turns pale. When the arms are lowered again, the veins on the dorsum of the hand fill slowly on the affected side. The arterial blood pressure is also always lower when measured in the affected arm.

Venous Thrombosis

Occlusion of the axillary or subclavian v. This condition, also known as effort syndrome or Paget–von Schrötter syndrome, is seen most commonly in young men, usually on the right side. It is rarely spontaneous; more commonly, it arises after heavy use of the arm, e. g., in sports. The venous occlusion manifests itself as a painful tension in the arm, often accompanied by swelling. The subcutaneous veins in the region of the arm provide an alternative path for venous return and are thus more clearly visible than normal. The thrombosed vein itself can sometimes be palpated in the axilla and is tender. It can often be unequivocally demonstrated with neuroimaging studies and Doppler ultrasonography. The prognosis is usually good; operative thrombectomy is only rarely necessary.

“Arm Pain of Overuse”

The nonphysiological, prolonged, and repeated performance of specific movements of the upper limb(s), particularly at the workplace (e. g., typing, working at a cash register, or long and monotonous use of other kinds of machines), can produce intractable pain in the upper limb extending well beyond the muscles that were used in the repeated movement. Pain of this type leads, in turn, to excessive reliance on other muscle groups, so that these, too, become involved in the pain syndrome. This condition and its pathogenesis are described further under “Pseudoradicular Pain” (below).

Other Types of Arm Pain

Glomus tumors are small, benign growths that originate in the glomus organs of the skin. They are composed of arteriovenous anastomoses in close association with autonomic fibers. Clinically, they are characterized by a dull painthat worsens when the arm hangs down and, particularly, when the arm swings as the patient walks. Local pressure over the tumor also causes pain. Glomus tumors are often found at the fingertips, where they may be visible as a bluish spot under the fingernail, but they can also arise practically anywhere else, including on the lower limbs.

“Referred pain.” Diseases of the internal organs commonly cause referred pain in the shoulder and arm. Pain is felt in the right shoulder in gall bladder disease, for example, and in the left arm in angina pectoris.

Gout. An exacerbation of gout can produce extremely severe, acute pain in a hand (chiragra) or foot (podagra). Chiragra is sometimes, but not always, restricted to the metacarpophalangeal joint of the thumb.

Image  Pain in the Trunk and Back

The back is by far the most common site of pain in the trunk. It is usually due to pathological abnormalities of the spine, which lead, in turn, to abnormal posture and nonphysiological activation of the muscles of the back.

Table 13.11 provides an overview of these painful syndromes, their localization, and the types of pain they produce. A few of them will be described in detail in the following paragraphs.

Image

Thoracic and Abdominal Wall Pain

Diseases of the internal organs are the most common cause of pain in the thoracic and abdominal wall (see “referred pain” above). Chest pain is often due to diseases of the heart and lungs. Band-like painsuggests a (possibly intraspinal) process irritating one of the spinal nerve roots or segmental nerves. Abdominal wall pain often arises from the internal organs, but may also be due, for example, to compression of the ventral rami of the spinal nerve roots(e.g., compression of the caudal thoracic nerves in the rectus abdominis syndrome). The rare Spiegel hernia (cf. Table 13.11) is another possibility, as is an abnormally mobile tenth rib.

Back Pain

Back pain is a very common problem that often profoundly affects the sufferer's everyday life at work and at home. The pain cannot always be fully explained based on objectively demonstrable skeletal changes. The extent of the visible structural changes is often not commensurate with the intensity of the pain. The major causes of back pain are:

Structural changes of the spine cause the vast majority of cases of back pain. Osteochondrosis leads to reactive spondylotic changes and, therefore, increased stress on the intervertebral joints. This, in turn, causes faulty posture, reflex functional disturbances of the musculature, and, therefore, pain. A herniated intervertebral disk can compress a nerve root, producing acute pain radiating into the periphery (p. 210). Abnormal postures of the spine, as in ankylosing spondylitis or scoliosis, often cause intractable back pain because of the associated nonphysiological stress on the muscles of the trunk and back. Spondylolisthesis, the sliding of one vertebral body on another (with or without spondylolysis, i. e., a defect of the pars interarticularis of the vertebral arch), is a congenital anomaly that usually remains clinically silent until later in life. It sometimes becomes symptomatic after an accident.

Pathological changes of the sacroiliac joint typically produce pain that worsens when the patient stands on one leg or hyperextends the leg on the affected side (Mennell maneuver).

Entrapment neuropathies are responsible for some cases of back pain of nonskeletal origin. Notalgia paresthetica, for example, is a rare entrapment neuropathy of the sensory dorsal rami of the thoracic spinal nerves as they pass through small apertures in the fascia (see p. 232).

Coccygodynia, i. e., intractable pain in the region of the coccyx, can arise after local trauma (a fall on the buttocks) or spontaneously. In the latter case, the diagnostic evaluation should include a search for tumors or infectious/inflammatory changes in the pelvis, as well as cysts of the lumbosacral nerve root sleeves (= Tarlov cysts).

Groin Pain

Pain in the groin can be caused not only by bladder conditions, gynecologic diseases, and inguinal hernias, but also by peripheral nerve lesions. The ilioinguinal nerve syndrome, a type of entrapment neuropathy, is described in Table 13.11. The pain of spermatic neuralgia is felt in the scrotum. In general, when the cause of groin pain is unclear, a pathological process should be sought in the pelvis.

Image  Leg Pain

Pain in the leg, like pain in the arm, has many causes. Common causes are degenerative and traumatic joint and soft tissue processes, lumbar disk herniation, and pathology in the lumbar spinal canal.Others include polyneuropathies, entrapment neuropathies, and restless legs syndrome. Vascular diseases, too, play an important role, particularly arterial occlusive disease.

Pain in the hip is usually due to diseases of the hip joint, most often degenerative arthritis (coxarthrosis). A diagnosis that is often missed is periarthropathy of the hip: in this condition, the joint itself is not diseased, but the soft tissues around it give rise to intractable pain, which frequently lasts for months. In algodystrophy of the hip, local pain is followed, some time afterward, by the development of osteopenia of the femoral head. Both the pain and the osteopenia usually resolve spontaneously.

Thigh pain may be due to a local process such as a sarcoma. An upper lumbar disk herniation or other lesion causing nerve root irritation can produce referred pain in the thigh. Meralgia paresthetica, a type of entrapment neuropathy causing pain in the thigh, is described on p. 234. Acute thigh pain and femoral nerve palsy can be caused either by diabetic neuropathy or by a hematoma in the psoas sheath.

Knee pain is usually of orthopedic, rheumatological, or traumatic origin. A proximal lesion of the obturator n. produces referred pain in the popliteal fossa in How-ship–Romberg syndrome (p. 236). Spontaneous or mechanically induced lesions of the infrapatellar branch of the saphenous n. are a further cause of pain in the knee.

Pain in the lower leg that is present only when the patient walks is typical of vasogenic intermittent claudication, a syndrome whose cause usually lies in the arteries, less commonly in the veins. Neurogenic intermittent claudication is caused by compression of the cauda equina in lumbar spinal stenosis (p. 213). Vasogenic intermittent claudication is worse when the patient walks uphill, while the neurogenic type is worse when the patient walks downhill. In the anterior tibial artery syndrome, pain develops acutely on the anterior aspect of the lower leg, particularly with exercise (p. 239). The saphenous n. can be caught in a fascial gap on the medial side of the lower leg, or, alternatively, in Hunter's canal in the thigh; pain ensues in the cutaneous zone innervated by this nerve (entrapment neuropathy).

Pain in the foot is a common complaint. It is usually unilateral and caused by an orthopedic condition, or by trauma. Tarsal tunnel syndrome, which typically arises after an ankle sprain, causes pain in the sole of the foot when the patient walks; it is described on p. 241Morton's metatarsalgia is described in the same section. Bilateral, burning pain in the feet characterizes erythromelalgia of vasomotor origin,otherwise known as burning feet syndrome.Similar symptoms may arise in polyneuropathy, but are then usually accompanied by objective neurological findings (loss of Achilles reflexes, distal sensory deficit). In “restless legs syndrome,” the restlessness, which is perceived as painful, forces the sufferer to stand up, walk around, and move the legs time and again, particularly at night or after prolonged sitting in a soft chair. This syndrome usually responds to small doses of L-DOPA, as well as to dopamine agonists.

Image  Pseudoradicular Pain

This term denotes an etiologically heterogeneous collection of painful syndromes caused by a faulty synergy of the muscles and joints. The faulty synergy arises either from structural joint changes or from nonphysiological movements putting excessive stress on the musculoskeletal system.

Pathophysiology. The joints of the body have a continuous, dynamic relationship with the muscles that move them. Afferent nerve impulses arising in the joints are fed back to the muscles to regulate and coordinate the timing and strength of muscle contraction. Thus, pathological impulses arising from mechanically damaged or otherwise dysfunctional joints lead to nonphysiologic patterns of muscle activation. In addition, movements that are repeated monotonously or that put the joints in an unfavorable position (“nonergonomic” movements) cause pain of the participating anatomic structures through overuse. Different names are used for the resulting pain syndromes, depending on the specialty and school of thought of the physician or other expert consulted: tendomyalgia, tendomyosis, pseudoradicular pain, myofascial syndrome, muscular rheumatism, and so forth.

Clinical manifestations. Pseudoradicular pain can arise in many different regions of the body but is particularly common in the upper limb. The pain is chronic and difficult to treat, because it is constantly reactivated by the daily (over)use of the involved joints and muscles.

The general features of pseudoradicular pain are as follows:

Image the pain is of greater or lesser intensity,

Image usually radiates into a single limb,

Image is exacerbated by the use of this limb,

Image and causes an antalgic restriction of movement;

Image there are painful trigger points and painful tendon attachments;

Image there is no objectifiable sensory deficit, paresis, or reflex abnormality;

Image nonphysiologic, antalgic movement leads to the perpetuation, extension, and chronification of the pain.

Treatment and prognosis. This condition is difficult to treat. The most useful approach consists of good occupational hygiene (use of the affected muscles only up to the pain threshold), changing the illness-producing behavior (switch to a different task at work), and passive measures such as trigger-point therapy. Much patience is demanded of both doctor and patient.