• Indicated by the presence of one or more of the following symptoms:
Short-term memory loss
Ringing in the ears
Reduced blood flow to the brain based on ultrasound exam
Cerebral vascular insufficiency (CVI)—decreased blood supply to the brain—is extremely common among the elderly in developed countries owing to the high prevalence of atherosclerosis (hardening of the arteries). The artery affected in most cases is the carotid artery. A pair of carotid arteries—one on each side of the neck running parallel to the jugular vein—are the main arteries that supply blood to the brain.
Typically, the problem develops at the carotid bifurcation—the splitting of the carotid artery into the internal branch (supplying the brain) and the external branch (supplying the face and scalp). This bifurcation is similar to a stream splitting into two branches. At the bifurcation, just as at the splitting of the stream, debris and sediment accumulate. Significant symptoms begin to appear in most cases only when the blockage of the artery has reached 90%. This situation is similar to what occurs in angina (see the chapter “Angina”).
Symptoms of cerebral vascular insufficiency are caused by reduced blood flow and oxygen supply to the brain. Severe disruption of blood and oxygen supply results in a stroke. The official definition of a stroke is loss of nerve function for at least 24 hours due to lack of oxygen. Some strokes are quite mild; others can leave a person paralyzed, in a coma, or unable to talk, depending on which part of the brain is affected. Smaller “mini-strokes,” or transient ischemic attacks (TIAs), may result in loss of nerve function for an hour or more, but less than 24 hours. TIAs may produce transient symptoms of CVI: dizziness, ringing in the ears, blurred vision, confusion, and so on. Repeated TIAs are serious, as over time they can result in substantial, progressive damage to brain function. What makes this so insidious is that the lack of a sudden event can mask the problem, so it is not recognized until too late.
Anyone who experiences signs and symptoms of CVI should consult a physician immediately for proper evaluation. In the past, evaluation of blood flow to the brain involved invasive techniques such as cerebral angiography. This procedure was similar to a cardiac (heart) angiogram (see the chapter “Angina”) and carried a relatively high side-effect rate: it caused a stroke in roughly 4% of the subjects. The modern evaluation of blood flow to the brain primarily involves the use of ultrasound techniques. These techniques determine the rate of blood flow and the degree of blockage by using sound waves.
The considerations and recommendations in the chapter “Heart and Cardiovascular Health” are appropriate here, since the primary goal is to improve blood flow by making the arteries healthier. Diet is particularly important, as stroke patients, especially those with significant blockage of the carotid arteries, tend to have an unfavorable dietary pattern (high intake of saturated fatty acids; low intake of fruits, vegetables, and omega-3 fatty acids) that may have been a key factor leading to their stroke.1 It is also important to address any other underlying factors, such as high cholesterol levels or high blood pressure. Beyond these general recommendations, we will offer a discussion of two natural medicines with proven benefits in CVI: fish oils and ginkgo biloba extract.
Before we discuss these natural approaches, it is important to take a look at a surgical procedures that is often recommended for patients with CVI: carotid endarterectomy. The internal, common, and external carotid arteries are clamped, the lining of the internal carotid artery is opened, and the atherosclerotic plaque is removed. This surgery is risky: approximately 6 to 10% of patients will either die or suffer severe neurological damage as a result of a stroke during the surgery, and about 7 to 11% of the patients will die during or soon (less than one month) after having a carotid endarterectomy. Newer, less invasive procedures include angioplasty done by threading catheters through the femoral artery in the leg and up through the aorta to the carotid, then inflating a balloon to dilate the artery. Often a wire-mesh stent (tube) is placed in the artery. However, it remains controversial whether angioplasty is actually safer or produces better outcomes. What is known is that carotid endarterectomies or angioplasties are of no value to patients with less than 70% blockage (as determined by an angiograph).2–6
If you have symptoms of severe CVI, including frequent TIAs or a past stroke, along with severe (greater than 70%) blockage of the carotid artery, then carotid endarterectomy or angioplasty may be appropriate. However, we recommend that you consult a qualified EDTA chelation specialist before electing to go ahead with these procedures. For a discussion of EDTA and referrals, see the chapter “Angina.”
The importance of fish oils for the patient with CVI cannot be overstated. Just as the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) protect against heart disease, they are also protective against a stroke. Low levels of EPA and DHA are found in the atherosclerotic plaque in the carotid arteries of patients with significant carotid blockage, while supplementation with EPA + DHA is associated with reducing inflammation within the atherosclerotic plaque, thereby reducing the likelihood that the plaque will rupture and lead to blood clots that may cause a stroke.7,8 The recommended dosage for prevention is 1,000 mg EPA + DHA.
Ginkgo biloba extract (GBE) has been the subject of more than 40 double-blind studies on the treatment of cerebral vascular insufficiency. In well-designed studies, GBE has produced statistically significant improvement in the major symptoms of CVI as well as in impaired mental performance. These symptoms included short-term memory loss, vertigo, headache, ringing in the ears, lack of vigilance, and depression. These results suggest that vascular insufficiency, not a true degenerative process, may be the major cause of these so-called age-related cerebral disorders.9
There has been some concern that GBE may increase bleeding risk when used with warfarin (Coumadin), aspirin, and antiplatelet therapies. However, a study evaluating the use of GBE and warfarin concurrently revealed no change in the international normalized ratio (INR), which is the blood test used to monitor a patient’s possible bleeding risk in response to anticoagulation therapy.10 Results from controlled studies consistently indicate that ginkgo does not significantly affect bleeding time or platelet aggregation, nor does it adversely affect the safety of aspirin or warfarin.11
• Symptoms of cerebral vascular insufficiency are associated with reduced blood flow and oxygen supply to the brain.
• Anyone who experiences signs and symptoms of cerebral vascular insufficiency should consult a physician immediately.
• The modern evaluation of blood flow to the brain involves the use of ultrasound techniques.
• Carotid endarterectomy and angioplasty are highly controversial surgical procedures because approximately 6 to 10% of patients will either die or suffer severe neurological damage as a result of a stroke during the procedure.
• Fish oils are especially helpful for reducing the inflammation associated with strokes.
• In well-designed studies, ginkgo biloba extract has produced a statistically significant regression of the major symptoms of cerebral vascular insufficiency and impaired mental performance.
In most cases, CVI is a consequence of atherosclerosis. Appropriate treatment involves following the recommendations in the chapter “Heart and Cardiovascular Health.” It may also be appropriate to consult the chapters “High Cholesterol and/or Triglycerides” and “High Blood Pressure.” The primary therapeutic goal in the treatment of CVI is to enhance the blood and oxygen supply to the brain. Ginkgo biloba extract has shown excellent results in this regard. The recommended dosage of GBE (24% ginkgo flavonglycosides) is 240 to 320 mg per day.