The cerebellum is a dense structure located at the base of the brain. Often referred to as the “little brain,” this region accounts for only about ten percent of the brain’s total volume but contains a majority of its neurons. Its primary function is not to initiate movement, but rather to fine-tune ongoing motor activity, maintain posture, and regulate balance. A cerebellar stroke occurs when the blood supply to this specific area is suddenly interrupted, leading rapidly to cell death.
Anatomy and Types of Cerebellar Strokes
The cerebellum receives its blood supply from three pairs of arteries that branch off the vertebrobasilar system. These vessels are the Superior Cerebellar Artery (SCA), the Anterior Inferior Cerebellar Artery (AICA), and the Posterior Inferior Cerebellar Artery (PICA). PICA occlusion is the most frequent cause of an ischemic cerebellar stroke.
Cerebellar strokes are categorized as ischemic or hemorrhagic. An ischemic stroke is far more common, resulting from a blockage, typically a blood clot that travels from the heart or a major neck artery and becomes lodged in one of the cerebellar arteries. A hemorrhagic stroke, in contrast, involves a blood vessel rupturing within the cerebellum, causing blood to leak into the surrounding brain tissue. This bleeding is often associated with long-term high blood pressure.
Identifying the Specific Symptoms
Damage to the cerebellum manifests in distinct symptoms that reflect its role in coordinating movement and balance. The most characteristic symptom is ataxia, a severe loss of coordination and clumsiness affecting the limbs and gait. People with ataxia often present with an unsteady, wide-based walking pattern that can look like staggering.
Another common symptom is severe vertigo, described as a feeling that the room is spinning, often accompanied by nausea and vomiting. This occurs because the cerebellum processes sensory information from the vestibular system, which regulates the body’s sense of spatial orientation and balance.
Oculomotor deficits are also frequently observed, most notably nystagmus, which involves involuntary, rhythmic, and rapid movements of the eyes. The cerebellum normally works to coordinate eye movements and stabilize gaze, so its injury results in these uncontrollable flickers.
Dysarthria is characterized by slurred, slow, or poorly articulated speech, occurring because the stroke has impaired the precise coordination of the muscles in the mouth, tongue, and larynx. Symptoms vary depending on which cerebellar artery is affected; PICA infarcts are often associated with vertigo and headache, while SCA infarcts tend to cause more pronounced limb and gait ataxia.
Acute Diagnosis and Emergency Treatment
The immediate medical response to a suspected cerebellar stroke begins with rapid diagnostic imaging, because the time elapsed since symptom onset heavily influences treatment options. A non-contrast Computed Tomography (CT) scan is typically the first test performed to quickly rule out a hemorrhagic stroke, as this type of bleeding must be identified immediately. However, the cerebellum is located in the posterior fossa, an area where bone artifact can obscure soft tissue, making early ischemic changes difficult to see on a standard CT scan.
For this reason, a Magnetic Resonance Imaging (MRI) scan, particularly a sequence called Diffusion-Weighted Imaging (DWI), is considered superior for confirming an acute ischemic stroke in the cerebellum. MRI can detect the subtle damage in the posterior fossa within minutes to hours of the event. The imaging also helps doctors determine the size of the stroke and the potential for swelling.
Emergency treatment depends on the stroke type and the time window. For an ischemic stroke, if the patient arrives within three to four-and-a-half hours of symptom onset, they may be eligible for intravenous thrombolysis using tissue plasminogen activator (tPA) to dissolve the clot and restore blood flow. If the blockage is in a large vessel, a procedure called endovascular thrombectomy, which involves mechanically removing the clot, may be considered.
Hemorrhagic strokes and large ischemic strokes carry a distinct risk of brainstem compression because the cerebellum is located in a confined space. The swelling that follows a stroke can cause a dangerous buildup of pressure, leading to obstructive hydrocephalus or herniation. In these cases, neurosurgical interventions like external ventricular drainage (EVD) to relieve fluid buildup or suboccipital decompression to relieve pressure on the brainstem may be necessary to prevent catastrophic outcomes.
Recovery and Rehabilitation Pathways
After the acute medical crisis is stabilized, the focus shifts to recovery, which is heavily dependent on the brain’s ability to reorganize itself through neuroplasticity. This inherent mechanism allows healthy areas of the brain to take over functions that were previously controlled by the damaged cerebellar tissue. Rehabilitation is a highly individualized and multidisciplinary process.
Physical Therapy (PT) concentrates on intensive balance and gait training to help the patient overcome residual ataxia and improve mobility. Occupational Therapy (OT) helps patients regain the fine motor skills necessary for activities of daily living, such as dressing, eating, and writing. These tasks are practiced repetitively to stimulate the formation of new neural connections.
For patients experiencing dysarthria, Speech Therapy focuses on exercises to improve the strength and coordination of the muscles used for articulation and voice control. Dedicated and repetitive practice in these therapies leverages neuroplasticity to maximize the restoration of function and improve long-term independence.