What are the consequences and treatment options for cerebellar circuit dysfunction?

Management of Cerebellar Circuit Dysfunction

Cerebellar circuit dysfunction requires prompt recognition and targeted intervention, with surgical decompression being the most effective treatment for deteriorating patients with cerebellar infarction. 1

Clinical Manifestations of Cerebellar Circuit Dysfunction

• Cerebellar dysfunction can manifest as motor symptoms including ataxia, dysmetria, dyschronometria, dysdiadochokinesia, and unsteady gait characterized by widened base, irregular steps, and lateral veering 2
• Non-motor manifestations include cognitive impairments (executive function, visual-spatial processing, linguistic deficits) and affective dysregulation when cerebellar circuits connecting to cerebral association cortices are affected 3
• Movement disorders such as action tremor, Holmes' tremor, palatal tremor, asterixis, and dystonia can result from cerebrovascular lesions affecting cerebellar circuits 4
• Cerebellar circuit dysfunction plays a role in neuropsychiatric conditions including obsessive-compulsive disorder through disruption of cortico-striato-thalamo-cortical circuits 1

Recognition of Deterioration in Cerebellar Dysfunction

• Monitor for decreased level of arousal or new brainstem signs, which indicate deterioration in cerebellar stroke 5
• Clinical deterioration manifests as brainstem compression, depression in consciousness level, Glasgow Coma Scale score <12 on admission, or a decline of ≥2 points 1
• Watch for radiographic deterioration appearing as fourth ventricular compression and evidence of hydrocephalus 1
• Advanced deterioration may present with pupillary anisocoria, pinpoint pupils, loss of oculocephalic responses, bradycardia, irregular breathing patterns, and sudden apnea 5

Medical Management

• Transfer patients with significant cerebellar dysfunction to an intensive care or stroke unit for comprehensive treatment and close monitoring 1
• Position the patient with head elevation between 0° and 30° to help manage intracranial pressure 5
• Ensure sufficient cerebral oxygenation and correct hypovolemia with isotonic fluids 5
• Osmotic therapy (mannitol or hypertonic saline) is reasonable for patients with clinical deterioration from cerebellar swelling 1
• Maintain normoglycemia (glucose <8 mmol/L) and treat hyperthermia 5
• Avoid hypothermia, barbiturates, and corticosteroids as they lack sufficient evidence in the setting of ischemic cerebellar swelling 1

Surgical Management for Cerebellar Infarction

• Obtain early neurosurgical consultation to facilitate planning of potential decompressive surgery 5
• In patients with cerebellar stroke who deteriorate neurologically, suboccipital craniectomy with dural expansion should be performed 1
• If ventriculostomy is needed to relieve obstructive hydrocephalus, it should be accompanied by decompressive suboccipital craniectomy to avoid upward cerebellar displacement 1
• Surgery after cerebellar infarct leads to acceptable functional outcomes in most patients 1

Treatment of Medication-Induced Cerebellar Dysfunction

• For cerebellar syndrome induced by high-dose cytarabine or other chemotherapeutic agents (bortezomib, rituximab, trastuzumab), the causative drug should be discontinued immediately 1
• In patients receiving cytarabine, avoid very high doses especially in those with renal impairment 1
• Recovery from medication-induced cerebellar dysfunction is variable, ranging from complete remission to persistent disabling ataxia 1

Management of Posterior Reversible Encephalopathy Syndrome (PRES) Affecting Cerebellum

• Stringent blood pressure control is crucial when PRES affects cerebellar regions 1
• Treatment requires cessation of the causative agent (often anticancer therapy) and antiepileptic treatment if seizures occur 1
• PRES typically resolves within 2 weeks with appropriate supportive management 1

Considerations for Non-Motor Cerebellar Dysfunction

• Cerebellar circuits contribute to cognitive and emotional processing through connections with cerebral association cortices 3
• Dysfunction in posterior lobe lesions (lobules VI and VII) can disrupt cognitive functions 3
• Vermis lesions may contribute to neuropsychiatric disorders by affecting cerebro-cerebellar-limbic loops 3
• In obsessive-compulsive disorder, cerebellar circuits interact with cortico-striato-thalamo-cortical pathways, potentially contributing to compulsive behaviors 1

Monitoring and Follow-up

• Patients with territorial cerebellar infarctions require monitoring for up to 5 days, even if initially stable 5
• Regular assessment of neurological status, particularly level of consciousness and brainstem signs, is essential 1
• Monitor for development of obstructive hydrocephalus, which is a secondary manifestation in most instances of cerebellar swelling 5