Learn the Sudden-Onset Signs of ‘Seasick’ Stroke

‘Seasick’ Stroke:- Know the symptoms, says Shlee S. Song, MD, director of the Comprehensive Stroke Center and the Telestroke Program at Cedars-Sinai.

Unfortunately, while many people are on the lookout for well-known symptoms such as paralysis on one side of the body or face, some 20% of strokes don’t cause those symptoms, Song said. Called posterior circulation strokes, they occur in the arteries that supply blood to the back of the brain and are often mistaken for other ailments.

Song sat down with the Cedars-Sinai Newsroom to discuss the signs and symptoms of this under-recognized type of stroke.

How are symptoms of posterior circulation stroke different from the symptoms that people recognize for other stroke types?

Patients with posterior circulation stroke can appear as if intoxicated or on a rocking boat, with dizziness, loss of balance and coordination, and nausea. Posterior circulation stroke can also cause larger blind spots, double vision, hearing loss, and trouble with swallowing.

To help people recognize signs of all types of stroke, we use the acronym BE FAST. This stands for “balance” and “eyes,” which are signs of posterior circulation stroke, plus “face,” “arms,” and “speech,” which are more commonly recognized stroke signs. The T is for “time,” because if you suspect someone is having a stroke, it is time to call 911.

What makes posterior circulation strokes particularly dangerous?

Because of the more subtle symptoms to witnesses or bystanders, these strokes are more likely than other stroke types to be misdiagnosed or delayed in diagnosis. It's very common for these patients to miss the time window for treatment—which can mean permanent disability or even death. Some people assume the tipsiness and loss of balance are due to a sedative or sleeping pill they took, or maybe an inner ear issue. Because of the gastrointestinal symptoms, some patients may assume that it is something they ate, or a GI infection. People experiencing vision changes might go first to the ophthalmologist or optometrist. Sometimes even patients who come to the emergency department have their diagnosis delayed because they are in a bed or on a stretcher, and it takes some time to determine that they have loss of balance or coordination because walking assessments are not often part of stroke screening.

How can people tell the difference between posterior circulation stroke and these other conditions?

While a gastrointestinal infection, inner ear problem or vision problem usually comes on gradually and builds over time, strokes happen suddenly. Stroke symptoms hit patients like a lightning bolt, out of the blue.

What treatments are available for posterior circulation stroke?

If a patient has a clot, we have drugs that can dissolve it and get the blocked vessel open. If the patient’s clot is too large to be dissolved with medication, our interventional colleagues can go in with a catheter and remove the clot. If a patient has a burst blood vessel, we can make sure their blood pressure is controlled and reverse the action of any blood thinners they might be taking. This prevents blood from accumulating in that smaller area in the back side of the head, where space is limited. Swelling that can occur after a posterior circulation stroke can compress critical brain structures.

What are the risk factors for posterior circulation stroke?

Some are similar to risk factors for other stroke types. Uncontrolled high blood pressure, high cholesterol, and diabetes all increase risk for stroke. For posterior circulation stroke, sudden trauma to the neck can also increase risk for artery dissection. Common causes of this include car accidents, whiplash injuries and sports neck trauma. These types of injuries can cause a tear in the inner wall of an artery. Clots can form around the vessel tear and block blood flow.

So be gentle with the neck. Avoid chiropractic neck manipulations and deep tissue massage at the neck, because such critical blood vessels are there. Take care with inversions in yoga and Pilates, and in martial arts classes where there might be twisting or hyperextending of the neck. If it feels uncomfortable, that's your body signaling to say this neck turn is probably a little too much.

And if you are injured, especially if you experience any loss of function, no matter how temporary, you need an appropriate evaluation. This should include blood vessel studies to look at the flow inside the blood vessels, so that we can see if there is a vessel tear or blockage. Newswise/SP