Features July 2011 Issue

Know How to Respond to Overnight Strokes

Itís not unusual to wake up with the feeling that your arm or leg has gone to sleep. You may chalk it up to just having "slept wrong." But if you wake up with feelings of numbness on one side, a difficulty talking or understanding speech, or trouble walking, the cause may be much more serious. A recent study found that one in seven strokes occur during sleep, and many of those stroke patients could have been treated had they been seen by a doctor soon after waking up.

Illustration: Marty Bee

Patients who are having an ischemic stroke, which occurs when a blood clot blocks blood flow to the brain, sometimes can be treated with the drug tPA. The clot-busting drug can be given intravenously or delivered directly to the site of the blockage with a catheter.

The study, published in the May 10 issue of the journal Neurology, found that at least one third of the people who with "wake-up" stroke symptoms could have been treated with the clot-busting drug tissue plasminogen activator (tPA). The drug is given to patients with ischemic strokes, those caused by a blood clot, but usually just if symptoms started less than four and a half hours before the medication can be administered. Beyond that point, the effectiveness of tPA becomes negligible and may actually increase the risk of bleeding, according to Ken Uchino, MD, director of the Vascular Neurology Fellowship at the Cerebrovascular Center at Cleveland Clinic.

But if you wake up with stroke symptoms and are unable to pinpoint when the symptoms started, you should still get to a stroke center as soon as possible. Researchers suggested that the onset of a stroke may be what wakes many people up, so that the window of time that tPA can be administered effectively and safely, is likely open for plenty of patients.

"Beyond the standard treatment, there are still situations in which the team of doctors might decide to treat the stroke early to keep the injury small," Dr. Uchino says. "Mild symptoms upon awakening, but subsequently worsening, might change the standard decision making. So get to a stroke center as soon as possible."

He adds that research is underway to develop treatments that extend beyond the current window of treatment. But no matter what treatment is available, the key to stroke treatment is always going to hinge on a rapid response to symptom onset.

"Most strokes occur without warning and can occur any time," Dr. Uchino says. "The cause of stroke appears to be no different during sleep than during wakefulness. There is a slightly higher occurrence of strokes and heart attacks soon after awakening, which may relate to adrenaline surge and blood pressure rise. The exact trigger is unknown."

Know Stroke Symptoms

Whether you wake up with stroke symptoms or you experience them at any other time of day, itís important to recognize them quickly and call 911 promptly. The easiest way to remember important symptoms is to know the meaning of the acronym FAST (Face, Arms, Speech, Time). For Face, ask the stroke patient to smile and see if one side of the face droops. For Arms, ask the person to raise his arms and see if one side drifts downward. For Speech, ask the person to say a familiar phrase, such as the first line of the "Pledge of Allegiance," and listen for a slurring of words or unintelligible speech. The Time element is that if obvious symptoms are present, you need to get to a stroke center quickly, Dr. Uchino says.

"Recognizing a possible stroke and calling 911 to get to a certified stroke center is very important," Dr. Uchino says. "I encourage everyone to know stroke symptoms. Some states already have defined system to bring patients to designated stroke centers, but getting to a certified center is important."

Nighttime Risks

While a stroke can occur at any time, Dr. Uchino notes that sleep behaviors and changes in blood pressure overnight can affect your stroke risk.

"There is no known way to reduce the chance of nighttime stroke," he says. "However, there is an increasing recognition that what happens at night influences oneís overall chance of stroke. There is strong data linking sleep apnea to stroke and heart attacks. Blood pressure variation during sleep, which one normally does not measure, has also been linked to stroke risk. Donít hesitate to seek evaluation and treatment for sleep apnea. Signs of sleep apnea can be just fatigue or snoring."