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TREATMENT OF VERTEBROBASILAR TIA AND STROKE

Timothy C. Hain, MD . Page last modified: April 7, 2019

Strokes Tia

Here we are focusing on "dizzy" strokes, and not attempting to cover treatment of other types of strokes. These are generally "vertebrobasilar" strokes, meaning that they are caused by damage in the distribution of the blood vessels in the back of the head -- the vertebral and basilar arteries.

Acute treatment of stroke

The treatment of stroke has changed hugely in the last 10 years, but relatively little has changed with strokes that cause dizziness. No surgical treatment has shown to be effective for vertebrobasilar TIA or stroke. Generally speaking, acute "interventionist" treatments for strokes dominated by dizziness, such as TPA or thrombectomy are impractical due to risk of larger stroke or death."dizzy" strokes, most of the time, are brainstem strokes, and the stakes are high. A bleed into the brainstem will likely be fatal. It is presently not very feasible to do a thrombectomy on the tiny blood vessels that supply the brainstem.

For these reasons, these invasive stroke treatments for dizzy strokes are generally just costly sources of risk, rather than costly sources of benefit. Instead, one's goal should be to prevent the next one. So what we have left is mainly prevention, i.e., you may be able to move on to the next section.

Acute treatment of strokes that are outside of the vertebrobasilar territory (i.e. usually dizziness is not the main problem -- think paralysis).

For strokes in large vessels (such as the carotids or middle cerebral arteries), new methods include using TPA (tissue plasminogen activator) and thrombectomy. Both of these trade hope for a better outcome with risk of bleeding. As bleeds are more damaging than strokes from loss of blood supply, and the odds of a good outcome vs a bad outcome (including death) change over the 4-6 hour window that these treatments are possible, the judgment as to whether to go forward is not a trivial one.

For strokes involving bleeding, this is a "cows out of the barn situation", and one cannot get the blood to go back into the vessel, but one might be able to prevent more bleeding (i.e. keep more cows from leaving barn), but reducing blood pressure and if relevant, improve coagulation. It would be imprudent to use TPA for a stroke that had already bled.

Prevention of TIA and stroke

800,000 strokes occur every year in the US. It is estimated that about 80% are preventable. Control of blood pressure is the most important prevention measure -- not taking aspirin or whatever. This is ahead of diabetes and smoking.

Medications are used to "thin" the blood, and to treat elevated cholesterol which may predispose to hardening of the arteries. Life style and dietary changes may reduce risk.

Control of blood pressure -- this one is very important !

High blood pressure, particularly systolic pressure, should be rigorously controlled. A reasonable target is below 130/90. There are presently many highly effective medications for blood pressure. A reasonable treatment in many is a combination of an ace-inhibitor and a diuretic. This subject was recently reviewed by Messerli et al (2002) as well as Strauss (2002). It remains unclear how acutely and by how much blood pressure should be lowered after a stroke. Present thought is that all but the highest blood pressures should be left to settle spontaneously in the acute setting (Strauss, 2002).

Control of diabetes.

Diabetes should be carefully regulated. Again, this can be very important, and those who are running A1C levels of 10, need to bend all efforts to do "whatever it takes" to get their A1C down to <7. This is critically important. Weight loss is usually the biggest think one can do.

Blood "thinners":

When one has a dizzy stroke --this is usually the first thing done -- low dose aspirin. However, one should actually work on the blood pressure and diabetes as the first priority. This may involve taking drugs or losing weight.

Currently available medications which may improve blood flow include:

Aspirin. There have been very many randomized trials of antiplatelet therapy. There appears to be little difference in doses between 50 and 1500 mg/day while larger doses increase the risk of gastrointestinal bleeding (Strauss, 2002). Nevertheless, as little as 1 baby aspirin per day reduces stroke incidence by about 30%. Aspirin is only about half as effective as coumadin for prevention of strokes associated with atrial fibrillation. Aspirin is no better than placebo for asymptomatic carotid stenosis. NSAID's do not prevent strokes (Bak, 2003)

Ticlodipine (Ticlid). This is a drug similar to aspirin. It is slightly more effective than aspirin, perhaps about 8%, but also slightly more risky. Dose is 250 mg, twice/day. CBC Blood tests must be taken every 2 weeks for the first 3 months because of the risk of neutropenia (low white cell count). Diarrhea occurs in 10% of persons on this drug.

Coumadin (Warfarin). The effectiveness of this medication for vertebrobasilar TIA is controversial, but current medical practice is to use coumadin in patients who have failed aspirin treatment. Also, in atrial fibrillation, coumadin reduces stroke by two thirds and death by one third. In atrial fibrillation, it is presently felt that coumadin should be given to all of those in whom it is safe. More about this follows. Coumadin has a higher risk of bleeding complication than other treatments. It is generally felt that the combination of aspirin and coumadin is more dangerous. It is only used in situations such as those persons with artificial heart valves. Usual starting dose is 5 mg daily, draw blood 1/week till stable, then readjust based on PT. Target "INR" or International Normalized Ratio is usually 1.5-2.5 but those with more severe problems may get higher targets (2-3 in atrial fibrillation, for example, see later). Patients on certain drugs may need more or less Coumadin because of interactions. Coumadin is inexpensive !

There are also now newer oral anticoagulants, which are easier to manage and safer as well, but are immensely more costly than coumadin. Examples include dabigatran, edoxaban, rivaroxaban, and apixaban. These agents are ex-pen-sive ! Xarelto (rivaroxaban) is an example -- costs about $12/tablet as of 2016.

Dipyridamole (Persantine). Formerly used with aspirin, Persantine is now mainly used for patients on coumadin who have continued having TIAs in spite of adequate anticoagulation. Typical dose is 50 mg, three times/day. There is no added effect of combining this drug with aspirin.

Heparin. This intravenous medication is used in the hospital setting, in situations where there are repeated TIA's.

Low-molecular weight heparinoids. This medication is presently investigational. It is similar to heparin but does not require intravenous injection or frequent blood tests.

Pentoxifylline (Trental). Makes blood flow more freely. The usual dose is one tablet, three times/day. Pentoxifylline has not been proven to work in TIA. Still, lack of evidence is not the same as evidence of lack of effectiveness.

Antiarrhythmic drugs -- for those who have an irregular heart beat:

Atrial fibrillation (AF) affects roughly 2.3 million adults in the United States. The prevalence is high -- nearly 4% of persons aged 60 years or older and nearly 9% of those aged 80 or older (Waldo, 2004). Compared with persons having a normal heart rhythm, persons with atrial fibrillation have a 4 to 5 fold increase in the likelihood of stroke. The prevalence of atrial fibrillation in stroke has been increasing in recent years -- perhaps suggesting more AF or less competing causes.

Digoxin, beta blockers, verapamil, diltiazem, quinidine, procainamide, disopyramide, flecainide, propafenone, sotalol, and amiodarone are examples of medications that can make the heart more regular. Non-drug therapies such as ablation are also possible. These drugs have many side effects, especially amiodarone, which can include dizziness. It is often that these drugs are NOT used, but rather there is a combination of a rate control medication (such as metoprolol), and a blood thinner. This may be safer than taking the antiarrythmics such as amiodarone.

Special considerations regarding treatment in those with atrial fibrillation

Several studies involving atrial fibrillation (AF) patients have been conducted. Analysis of several trials revealed that risk of stroke can be reduced by 68% by giving warfarin (coumadin). Aspirin alone reduces risk by about 36%. In AF patients < 65 years of age with no other risk factor, the risk of stroke is about 1% per year, which has lead some to the conclusion that treatment with coumadin is not warranted.   In AF patients older than 65 years of age or less than 65 with one or more risk factors, data strongly supports the use of warfarin to reduce stroke.

Newer blood thinners are safer but much more costly than coumadin.

After a stroke has been sustained in the context of AF, coumadin (warfarin) reduces risk of stroke by 67% compared to 18% for aspirin. Tight control of the INR is very desirable -- it should be between 2-3.5 in patients less than 80 years old, and 2-3 in those greater than 80 years old.

Recent data suggests that mobile cardiac telemetry may be indicated to detect occult atrial fibrillation (Tayal et al, 2008). This is a device similar to a Holter monitor. There are "over the counter" cardiac monitors available for about $100. Implantable heart monitors also can detect occult atrial fibrillation at a very high cost.

Reduction of lipids in the blood -- a good idea.

Dietary treatment of hyperlipidemia

If cholesterol is greater than 200, diet should be modified. The "step 1" diet is low in saturated fat, has limited cholesterol (no more than 300 mg/day), and for overweight individuals, restricted in calories. The total fat caloric content of the diet should not exceed 30%. One should strive to decrease consumption of meats, which are high in saturated fat, and replace calories with complex carbohydrates (not sugar), or fish. Avoid saturated oils such as palm oil and butter, using unsaturated oils such as olive oils or nut oils where needed. Increasing fiber in the diet may help reduce cholesterol. A minimum of 6 months of dietary treatment should be attempted before initiating drug therapy unless LDL cholesterol is > 130 mg/dl. For this level of LDL alter diet and begin drug therapy simultaneously.  

Cholesterol should be rechecked at 4-6 weeks and 3 months after starting the diet. If the step-I diet fails (LDL not < 90-100), then proceed to the step-2 diet.

The step 2 diet limits saturated fat to less than 7% of total calories and cholesterol intake to less than 200 mg/day. Medications that reduce cholesterol such as lovastatin should be used if diet doesn't work. Those that are overweight should diet to reduce weight by 5 lbs/month till normal before starting any cholesterol lowering medications as reduction of weight is more effective than changes in diet or medication. It has been our observation that just eating less is generally more likely to work for weight loss than any other strategy.

Medication (such as a statin) may be indicated when response to diet is inadequate. Patients with high cholesterol should attempt to avoid use of medications in the "beta blocker" family as well as in the "thiazide" diuretic family. Both of these types of medications are commonly used for control of blood pressure.

Comment on dietary treatment: While lowered cholesterol and avoidance of being overweight reduces stroke risk, there is disagreement about whether or not restriction of dietary fat avoids stroke. Gilman et al (1997) reported that dietary fat intake was inversely associated with stroke risk, with the lowest age-adjusted cumulative stroke rate in men for individuals who had a total fat intake of calories amounting to 50% of their caloric intake,  and three times greater incidence for men with 26% intake. An alternative to the arduous and rigorous dietary treatment  that would take this into account this observation might be to combine a higher unsaturated fat intake with drug treatment (see below), and avoidance of obesity through reduced caloric intake.

A second issue is that it is very clear now that drugs that lower overall cholesterol decrease cardiac risk. It seems likely that the same will be shown in the future for stroke. This again might make one inclined to use drug treatment for cholesterol early on.

Drug Therapy for hyperlipidemia:

In recent years it has become clear that drugs that lower cholesterol can significantly reduce morbidity from vascular disease. Our thought is that many patients are so concerned about side effects from these drugs that they sacrifice years of their lives as well as a better quality of life if they had just "bit the bullet", and tolerated these drugs.

Heart attacks, in particular, are reduced by roughly 30% starting 6 months after beginning treatment in individuals with elevated cholesterol. Although at this writing there are no published studies regarding stroke, it seems likely that "statin" drugs eventually be shown to reduce risk by about 25% in stroke and TIA (Strauss, 2002). The trend in vascular medicine is to use these agents earlier and with a lessened emphasis on dietary treatment. A target of 100 mg/dL for LDL is thought to be appropriate (Strauss, 2002). The vast majority of patients with a history of ischemic stroke or transient ischemic attack could benefit from statin use (Stroke, 2004).

At this writing, fluvastatin is the least costly statin treatment for low risk patients who require LDL reductions of 15-25%. Pravastatin is an intermediate potency agent, and atorvastatin is suitable for patients who require very substantial reductions. Niacin and bile acid agents such as Questran are also effective agents, but side effects limit their usefulness. The statins are all very similar, so price may be a better guideline than anything else. A list of agents follows.

Brand Name Generic Name Mechanism Dose Cost
Nicolar, Niaspan Niacin Reduces triglyceride synthesis 1 g BID $10/100 tablets
Lopid gemfibrozil Unclear 600 BID $14/60 tablets
Lescol fluvastatin Statin 40 mg daily about $3/tablet
Colestid colestipol Reduces absorption of bile acids. 10 g/day divided  
Lipitor atorvastatin Statin 10-40 mg daily $230/50 tablets
Questran cholstyramine Binds bowel acids 8g/day divided $200-$600/60
Zocor simvistatin Statin 10 mg daily $110/30 tablets
Pravachol pravastatin Statin 20 mg daily $40/90 tablets
Mevacor lovastatin Statin 20 mg daily  
Zetia, Ezetrol; Vytorin with statin Ezetimibe Decreases cholesterol absorption 10 5-8$/single pill.
PCSK9   PCSK9 inhibitor   Anticipated about $20,000/year.

As can easily be seen, the non-insurance price of many of these drugs is extremely high, in spite of being generics.

Miscellaneous interventions

Estrogen replacement where appropriate is associated with a 25-50% reduction of risk from heart disease as well as 15% decrease in LDL and 15% increase in HDL. Estrogen use may also reduce the risk of osteoporosis. A potential increased risk of breast cancer remains.

Life style : Persons with a sedentary life style are at higher risk for stroke than those with active life styles. Persons who have had TIA, in general, should not restrict their activity, but rather, might even consider increasing activity. Driving, swimming, and operation of potentially dangerous equipment is obviously risky. While recommendations must be individualized, we do suggest caution and if possible, avoidance of these latter activities.

Vitamin supplements. Low serum homocysteine levels is correlated with a modest reduction in the risk of ischemic heart disease and stroke (The Homocysteine Studies Collaboration, 2003). Folate supplementation is probably reasonable in persons with low homocysteine.

Smoking cessation. Reducing smoking will reduce long-term vascular risk as well as cancer risk. This is not so easy.

Carotid endarterectomy

Carotid territory strokes rarely cause dizziness, and for this reason, endarterectomy is often not relevant. Nevertheless, carotid endarterectomy is beneficial in persons with symptomatic carotid disease and severe carotid stenosis, defined as 70% to 99%. Benefits in persons with severe stenosis decreased risk of about 50%. In those marginal stenosis, between 50-69%, the risk reduction was less (about 27%). Persons with less than 50% stenosis were harmed by surgery according to the NASCET study (Strauss et al, 2002). Increased risk of surgery correlates with previous stroke, blood pressure greater than 180, older than 75 years, and history of peripheral vascular disease. Other vascular lesions in the brain also increased the risk of stroke (Strauss, 2002).

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Copyright April 7, 2019 , Timothy C. Hain, M.D. All rights reserved. Last saved on April 7, 2019