Alzheimer's Pill May Help in Stroke

A new medication, memantine, which is at present used to treat Alzheimer’s disease, may also show promise in the treatment of stroke. If it is shown to have a beneficial effect on stroke recovery, it would be the first medication to aid in the recovery of damage following a stroke.

The currently available therapies that are used after a stroke do not directly treat the stroke itself. The existing medical management for stroke is focused on several things:

• Maintaining medical stability through steps such as fluid and electrolyte management to optimize stroke recovery.
• Reducing the chances of another stroke by preventing blood clot formation, often by using blood thinner medications.
• Identifying and controlling stroke risk factors such as hypertension, heart disease, diabetes, and high cholesterol.

Memantine is a relatively new medication currently used to treat the symptoms of some types of dementia. Known by the trade name Namenda, it has been shown to be moderately effective for preventing the progression of the symptoms of some types of dementia. It has been approved by the United States Food and Drug Administration for the treatment of moderate to severe Alzheimer's disease, which is one of the most common and recognized causes of dementia.

The mechanism of action of memantine is believed to lie in the inhibition of a chemical called glutamate. Glutamate has been shown to cause deterioration of neurons (brain cells) through a chemical process called neuroexcitatory damage. This type of neuroexcitatory brain cell injury is one of the mechanisms that play a role in the brain damage that occurs as a result of a stroke.

Stroke is an event characterized by interruption of blood supply to the brain.

The effect of the interruption blood supply (ischemia) on the brain is called infarction. Infarction means that the brain tissue suffers from toxic damage and may become dysfunctional, resulting in physical and mental disability after a stroke. Thus, inhibition of glutamate can inhibit neurotoxic damage, decreasing the damage caused by a stroke.

Medication that could potentially reduce the area of stroke damage would certainly be a breakthrough in stroke management. However, even a potential breakthrough has to be examined thoroughly to verify whether it is effective.

So far, studies show that memantine may reduce the area of infarcted brain tissue and improve neurological function in mice that have had a stroke, and thus it is possible that it could work in the same way in humans as well.

There have been a few studies evaluating the effects of memantine on humans. For example, a recent randomized, double-blind, placebo-controlled research experiment in Spain evaluated 28 stroke survivors who had aphasia (diminished speaking ability) after a stroke. The participants who received treatment with memantine showed more improvement in speaking ability as they recovered from their strokes than those who did not receive the medication.

It is always difficult to predict which medications will be developed and approved for the treatment of medical disorders. Generally, new medications that are proven to be effective and are found not to have serious side effects have a higher likelihood of approval and of becoming standard use. Thus far, memantine appears promising, particularly because there is already data available with regard to safety in the treatment of Alzheimer’s disease.

Currently, many different methods for saving infarcted brain tissue are being investigated, such as stem cell transplantation, electrical stimulation, and hypothermia, but none have advanced yet into widespread use. Memantine has an advantage over some of these methods because it is already produced as a medication, albeit as a medication for another condition besides stroke.

Stroke is among the most serious medical illnesses, and there are currently very few effective treatments for stroke. Much of the improvement after a stroke occurs because the brain heals on its own and because programs such as physical therapy and rehabilitation also maximize healing and improve a stroke survivor's physical and cognitive (thinking) abilities.

If you or a loved one has had a stroke, your doctor can provide you with the most updated treatment, or a referral for the most updated treatments available.