Catastrophic Neurologic Disorders in the Emergency Department , 2nd Edition

Chapter 5. Twitching and Spasms

The presentation of abnormal movements may doubtlessly have many causes, not to mention parallel systemic illness. Many emergency room physicians ask neurologists to classify, resolve, and treat the cause. Movement disorders may indicate a new lesion to the brain, may be due to drug effect, endocrine pathology, or connective tissue disease, or may even be factitious.1,2 Of patients with new movement disorders, the similarities between certain acute movement disorders would make recognition elusive, and particularly, naming the abnormal movement remains difficult when it presents as a mixture of things. (Even a proverbial neurologist, may say “I have no idea what this is.”)

This chapter attempts to clarify the commonly observed acute movement disorders in the emergency department but concentrates on the more serious and those that are drug-induced.

Clinical Assessment

In plain terms, involuntary movements are described using the following characteristics: rhythm, regularity, displacement by movement, generalized or same muscle group, presence or absence with relaxation, and whether the movement is fast, slow, flowing, or resembling spasm.3 Movement disorder can be very difficult to differentiate from a focal seizure or epileptic partialis continua. Staring, automatisms, and lip smacking may be absent, and the abnormality may just be a continuous repetitive jerk in one limb. Clonic jerks can be felt or seen and may evolve into a generalized seizure. (An electroencephalogram may be the only option to differentiate it from another movement disorder.)

Myoclonus is applied to muscle contractions that are brief, of small amplitude, and shock-like. The movements may be random or rhythmic, generalized or limited to one or multiple groups of muscles. Usually they are chaotic and arrhythmic but, when rhythmic, have been denoted as myorhythmias. Myoclonus due to lesions in the cortex is touch- and sound-sensitive and in awake patients caused by attempted motion (action myoclonus) or muscle stretch.4 Myoclonus can originate from the cortex, basal ganglia, brain stem, or spinal cord.5 In severe anoxic-ischemic brain injury, all of these locations may be involved. Myoclonus status epilepticus in a comatose patient after cardiac resuscitation is a result of devastating multilayer cortical damage and an indicator of poor prognosis (see Chapter 10).6

Drug-induced myoclonus may involve manifestations of first exposure or appear in toxic doses (Table 5.1).3,7,8,9,10,11 Generalized myoclonus is common in acute metabolic derangements but usually at end-stage organ failure such as hepatic and renal disease. It has been observed in hypernatremia, hypomagnesemia, and nonketotic hyperglycemia. Unusual causes are heat stroke, decompression injury, and pesticide exposure. The toxic exposure may have caused permanent damage to the cortex and basal ganglia (see Chapter 8).

Table 5.1. Drugs Causing Myoclonus

Drug Type



Monoamine oxidase inhibitors
Tricyclic antidepressants






Valproic acid

Calcium channel-blocking drugs


Opiate derivatives


Other drugs


Overdoses or poisonings

Antihistamine overdose
Methyl bromide fumes
Organic mercury poisoning
Gasoline sniffing
Dichloromethane ingestion
Strychnine poisoning
Chloralose (rodenticide)

Source: Adapted from Vadlamudi L, Wijdicks EFM: Multifocal myoclonus due to verapamil overdose. Neurology 58:984, 2002. By permission of Lippincott Williams & Wilkins.

Segmental myoclonus affecting the arm or leg may be due to acute spinal cord injury including trauma. Segmental myoclonus may closely mimicepilepsia partialis continua, in which the jerking movements are more regular and at a repetitive fast rate.

Dystonia is reserved for movements characterized by a persistent posture in one extremity. There is sustained patterned spasm but normal tone in between. The positions may be bizarre in the limbs and trunk.12 In the emergency department, it is useful to distinguish between a generalized or focal dystonia and whether dystonia occurs at rest. Sensory tricks (touching limb to reduce spasm), also known as geste antagoniste, are characteristic in dystonia. A form of dystonia is ocular deviation (oculogyric crises). Oculogyric crises may be associated with backward or lateral flexion of the neck, and the tongue may protrude. The deviation of the eyes upward, sideways, or downward is held for several minutes and can only for a brief moment be corrected by effort. This eye movement is commonly drug-induced, and discontinuation of the drug is rapidly successful. Oculogyric crises do occur in serious neurologic conditions such as bilateral para-median thalamic infarction, multiple sclerosis, head injury, and tumors in the ventricles. Drugs causing oculogyric crises and oromandibular dyskinesis include phenothiazines and many of the antipsychotic drugs but also carbamazepine, gabapentin, lithium, ondansetron, and, perhaps best known, metoclopramide (Fig. 5.1). However, they may be seen as a manifestation of schizophrenia alone. Acute drug-induced dystonia is not prevalent along with anti-psychotic drug use, but other well-established associations have been reported (Table 5.2).7,9,13

Dystonia is a common symptom in Parkinson's disease and neurodegenerative disorders associated with extrapyramidal signs, such as progressive supranuclear palsy, multisystem atrophy, corticobasal ganglia degeneration, and inherited movement disorders.14 Any physician seeing patients with acute dystonia should consider Wilson's disease, particularly when patients are 20–30 years old. Additional findings are artificial grin (retracted lips) and brown iris in previously blue-eyed persons. Diagnostic tests include reduced serum ceruloplasmin level (in 5% of patients it is normal), Kayser-Fleischer rings under slit lamp, and increased signal in basal ganglia and cortex on magnetic resonance imaging (MRI).

Chorea and athetosis are movements that are often combined and overlapping. Chorea is arrhythmic, with a jerky, thrusting component that is always purposeless but often incorporated into a voluntary movement. It may include grimacing, respiratory muscles producing grunts, or “dance-like” walk. Athetosis involves slow, undulating movements seen with the attempt to sustain a posture. Fairly typical movement patterns are known, such as alteration between extension-pronation and flexion-supination of arm, flexion-extension of fingers, and foot inversion. Pursing and parting of the lips or side-to-side movement of the neck is observed commonly.

Figure 5.1 Patient with oromandibular dystonia, oculogyric crises, and dystonic posturing after ondansetron administration. The facial images were made within 90 seconds.13

Drug-induced chorea is shown in Table 5.3, with a well-established presentation of central nervous system (CNS) stimulants and oral contraceptives.

Chorea gravidarum and its association with birth control medication show an increased susceptibility in some patients but many patients had prior Sydenham's chorea and heart valve damage from streptococcal infection. Chorea is also associated with new-onset hyperthyroidism, polycythemia vera, and systemic lupus erythematosus. Structural CNS lesions commonly involve ischemic or hemorrhagic stroke in basal ganglia but usually are one-sided (hemichorea).

Finally, tremor is common and diagnosed by synchronous contractions of opposing muscles. Tremor produces rhythmic oscillations. Acute tremors may indicate damage to the red nucleus (Benedikt's syndrome, see Table 15.2) that may produce a rubral tremor and has a frequency of 2–5 Hz. It is typically seen in action and with posture holding and not at rest.

Table 5.2. Durg-Induced Dystonia

Antiepileptic drugs
Calcium antagonists
Dopamine agonists
Monoamine oxidase inhibitors
Selective serotonin reuptake inhibitors

Drug-induced tremors (Table 5.4) are usually postural and primarily enhanced physiologic tremors. Withdrawal of alcohol, barbiturates, benzodiazepines, β-blockers, and opioids may produce tremors.

Certain rare entities can be encountered in the emergency department and require prompt action. Acute parkinsonism may be induced by toxins such as MPTP (l-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), organophosphates, carbon monoxide, carbon disulfide, cyanide, and methanol. It may also be particularly severe in acute withdrawal from dopaminergic drugs in patients with established Parkinson syndrome. Many chemotherapeutic agents have been implicated, including paclitaxel, vincristine, and CHOP (cyclophosphamide, hydroxydaunomycin, vincristine [Oncovin], and prednisone). Response to levodopa or prednisone is potentially present but not in toxic parkinsonism. Parkinsonism can be part of neuroleptic malignant syndrome, and fever, dysautonomia, and elevation of serum creatine kinase usually point in that direction (see Chapter 9).

Table 5.3. Drug-Induced Chorea

Tricyclic oral contraceptives
Tricyclic antidepressants
Selective serotonin reuptake inhibitors
Antiepileptic drugs

Table 5.4. Drug-Induced Tremors

Antiepileptic drugs
Antihyperglycemic drugs
Calcium channel blockers
Dopamine receptor-blocking agents

In addition, there are reasonably well-delineated disorders that include lethal catatonia (due to a prior major lesion to the CNS) and serotonin syndrome (due to serotonin-specific reuptake inhibitors, “ecstasy,” and a combination of monoamine oxidase inhibitors and meperidine).15,16 Neuroleptic malignant syndrome should be rapidly considered when hyperthermia, rigidity, autonomic features, and increased creatine kinase are present. Acute serotonin syndrome has a profile similar to any of the acute dysautonomias, but profound myoclonus and shivering may be present (Box 5.1).

Acute laryngeal dystonia may occur after recent administration of phenothiazine or other neuroleptic agents.17,18,19 Manji and coworkers20 from Queens Square London coined the term status dystonicus. Life-threatening complications occurred in these patients with respiratory failure due to upper airway obstruction or decreased respiratory function. Myoclonus may affect the diaphragm, and generalized dystonic spasm may impair swallowing. A tracheostomy was needed in more than a third of patients, and rhabdomyolysis from persistent spasm did occur.

Line of Action

Acute movement disorders could point to a structural lesion and justify an MRI scan. Paroxysmal dyskinesias, whether dystonia, chorea, or athetosis, could be due to a secondary cause.

Toxicity from overdose is a common occurrence, and one should not be satisfied with other explanations until they are carefully excluded. All drug-induced movement disorders are self-limiting, but failure to recognize their severity may lead to progression of the disorders, with hypotension and cardiac arrhythmias.

Box 5.1. Akinetic Rigid Crises with Hyperthermia

The diagnostic spectra of these mostly poorly understood disorders overlap and include profuse perspiration, fluctuating pulse rate and blood pressure, and hyperthermia due to impaired thermoregulation. Untreated, the condition leads to rhabdomyolysis and dehydration and may become lethal due to myocardial stress or deep venous thrombosis and pulmonary emboli. This condition may be drug-induced (neuroleptic agents or serotonin syndrome— mostly due to recent use or increase in dose of selective serotonin reuptake inhibitors) or due to drug withdrawal (dopamine withdrawal in severe Parkinson's disease or as a result of a major brain injury, encephalitis, or anoxic-ischemic damage). The degree of increase in creatine kinase is variable but expected, with prolonged symptoms. Therapy is supportive, with oxygenation, rehydration, anticoagulation, and options include dantrolene (1–10 mg/kg), bromocriptine (5 mg), lisuride (0.02–0,25 mg/hour), or, certainly not as a last resort, electro-convulsive therapy.

In patients with severe myoclonus, medication to enhance γ-aminobutyric acid (GABA) inhibition could be useful, including lorazepam and valproate. Propofol infusion (titrating to effect) is successful in myoclonus status epilepticus.6,21

Acute dystonic reactions are often successfully treated with intravenous or oral administration of anticholinergics (benztropine) or antihistaminic agents (diphenhydramine).22 Benzodiazepines may be useful as well. In status dystonicus, neuromuscular paralysis and sedation may be needed for several days, followed by benzhexol, tetrabenazine, and pimozide or haloperidol. Intravenous diphenhydramine 25–75 mg dramatically resolved the status in acute laryngeal dystonia.

Dantrolene, bromocriptine, lisuride, or electroconvulsive therapy is effective in neuroleptic malignant syndrome or lethal catatonia (Box 5.1).23Cyproheptadine has shown promise in serotonin syndrome.24 The management in movement disorders leading to major systemic involvement or airway involvement is summarized in Figure 5.2.

Figure 5.2 The four major acute movement disorders and initial therapy.


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