A Superior Cerebellar Artery (SCA) stroke occurs when blood flow to the cerebellum is blocked. The cerebellum is the part of the brain responsible for coordinating movement, balance, and posture. The superior cerebellar artery supplies oxygen-rich blood to the upper part of the cerebellum. When this artery is obstructed, the cerebellar tissue it nourishes begins to die, leading to a range of neurological symptoms.
Causes of Superior Cerebellar Artery Strokes
An SCA stroke is an ischemic stroke, caused by a blockage rather than bleeding, which happens in one of two ways. The first is a thrombus, where a blood clot forms directly within the superior cerebellar artery, often on top of fatty deposits called plaque from atherosclerosis. The second common cause is an embolus, a piece of a blood clot that forms elsewhere, breaks free, and travels through the bloodstream until it lodges in the artery.
These emboli often originate in the heart, particularly in individuals with a heart rhythm disorder called atrial fibrillation. Other risk factors that contribute to both clot formation and atherosclerosis include high blood pressure, high cholesterol, diabetes, and smoking.
Recognizing the Symptoms
The symptoms of an SCA stroke are related to the functions of the cerebellum and differ from more common signs of a stroke. One of the most prominent symptoms is ataxia, a lack of coordination that can manifest as an unsteady, “drunken” walking gait or clumsy movements of the arms and legs. Patients frequently experience vertigo, a sensation that the room is spinning, along with dizziness, nausea, and vomiting.
Another characteristic symptom is dysarthria, which is slurred or poorly coordinated speech due to the cerebellum’s role in controlling the muscles used for talking. Many individuals also develop nystagmus, which involves involuntary, rapid eye movements. A sudden, severe headache at the back of the head is another common indicator of a cerebellar stroke.
The Diagnostic Process
When a cerebellar stroke is suspected, diagnosis begins with a thorough neurological examination. A physician will test the patient’s coordination, balance, eye movements, and speech to identify deficits pointing to a problem in the cerebellum.
Brain imaging is the next step to confirm the diagnosis. A non-contrast computed tomography (CT) scan is performed first to rule out a hemorrhagic stroke, which is caused by bleeding in the brain and requires different treatment. To diagnose an ischemic stroke and pinpoint the blockage, magnetic resonance imaging (MRI) is used. An MRI provides a detailed view of the brain tissue, while a magnetic resonance angiogram (MRA) can visualize the blood vessels to confirm the arterial occlusion.
Medical Treatments for SCA Strokes
Immediate medical treatment for an SCA stroke focuses on restoring blood flow to the cerebellum. For eligible patients who arrive at the hospital within a few hours of symptom onset, a medication called tissue plasminogen activator (tPA) can be administered intravenously to dissolve the blood clot. In cases where the clot is larger or the patient is not a candidate for tPA, a mechanical thrombectomy may be performed. During this procedure, a catheter is threaded through an artery to the brain, where a device is used to retrieve and remove the clot.
After the initial emergency treatment, patients are placed on long-term medications to prevent another stroke. These often include antiplatelet drugs like aspirin, anticoagulants if the stroke was caused by atrial fibrillation, and statins to lower cholesterol and manage atherosclerosis.
Rehabilitation and Life After an SCA Stroke
After a patient’s condition is stabilized, the focus shifts to rehabilitation to address functional impairments caused by damage to the cerebellum. This recovery process involves a team of specialists. Physical therapists work with patients to improve balance, strength, and coordination, using specific exercises to retrain walking and reduce ataxia.
Occupational therapists help individuals relearn skills for daily living, like dressing, eating, and writing, which may have become difficult due to poor coordination. For those experiencing speech difficulties, a speech-language pathologist develops exercises to improve muscle control for clearer speech and address any swallowing problems. The recovery journey varies for each person, but consistent participation in these therapies is a factor in regaining function and independence.