What is the pathophysiology of a cerebellar (cerebral) stroke?

From the Guidelines

Cerebellar stroke is a life-threatening condition that occurs when blood flow to the cerebellum is disrupted, resulting in tissue damage and neurological dysfunction, and prompt recognition and treatment are crucial to prevent severe morbidity and mortality. The cerebellum, located at the back of the brain beneath the occipital lobes, primarily receives blood supply from three major vessels: the posterior inferior cerebellar artery (PICA), anterior inferior cerebellar artery (AICA), and superior cerebellar artery (SCA) 1. Cerebellar strokes can be either ischemic (caused by vessel occlusion) or hemorrhagic (caused by vessel rupture). In ischemic cerebellar stroke, which accounts for approximately 80% of cases, thrombosis or embolism blocks blood flow, leading to oxygen and nutrient deprivation in cerebellar tissue, initiating an ischemic cascade involving excitotoxicity, oxidative stress, and inflammatory responses that ultimately result in neuronal death 1.

The pathophysiology of cerebellar stroke involves a complex interplay of factors, including:

• Loss of function of membrane transporters, causing sodium and water influx into the necrotic or ischemic cell, leading to cytotoxic edema 1
• Disruption of the blood-brain barrier (BBB), leading to vasogenic edema 1
• Mass effect, increased intracranial pressure, and life-threatening complications like obstructive hydrocephalus or brainstem compression 1
• The cerebellum's role in coordination, balance, and motor learning means that damage manifests as ataxia, dysmetria, dysdiadochokinesia, nystagmus, and vertigo 1

Decompressive suboccipital craniectomy with dural expansion should be performed in patients with cerebellar infarction causing neurological deterioration from brainstem compression despite maximal medical therapy 1. The management of cerebellar stroke requires a multidisciplinary approach, including:

• Complex medical care, such as airway management and mechanical ventilation, blood pressure control, fluid management, and glucose and temperature control 1
• Surgical intervention, such as decompressive craniectomy, to relieve mass effect and prevent further brain damage 1
• Close monitoring of the patient for signs of neurological worsening and prompt recognition of complications like obstructive hydrocephalus or brainstem compression 1

From the Research

Pathophysiology of Cerebellar Stroke

• Cerebellar infarction is a significant cause of stroke, often presenting with non-specific symptoms such as dizziness, nausea, vomiting, unsteady gait, and headache 2.
• The clinical presentation of cerebellar stroke can be subtle, making accurate diagnosis challenging, and relying heavily on careful attention to patients' coordination, gait, and eye movements 2.
• Cerebellar stroke can result from various causes, including small vessel arteriolosclerosis, cardioembolism, and large artery athero-thromboembolism, with hypertension being a significant modifiable risk factor 3.
• The pathophysiology of cerebellar stroke involves vascular injury to the central nervous system, leading to acute, focal neurological deficits 3.

Clinical Features and Diagnosis

• Cerebellar stroke can present with a range of symptoms, including ataxia, dysarthria, and nystagmus, which can be overlooked or misdiagnosed as benign conditions 4.
• Early diagnosis is crucial to prevent potentially fatal complications, such as brainstem compression and obstructive hydrocephalus, and to identify and treat underlying vascular lesions 2.
• Imaging studies, such as brain CT or MRI, are essential for diagnosing cerebellar stroke, although early-stage posterior fossa ischemia may not be visible on initial imaging 2.

Treatment and Management

• Treatment of cerebellar stroke involves thrombolysis, anticoagulation, and antiplatelet therapy, depending on the underlying cause and patient's condition 5, 6.
• Intravenous thrombolysis with alteplase is recommended within 4.5 hours of stroke onset, although its use in patients with a history of cerebral hemorrhage requires careful consideration 5, 6.
• Mechanical thrombectomy and intra-arterial thrombolysis may be considered in selected cases, particularly for patients with large vessel occlusions 6.