What are the symptoms and treatment options for cerebellar disorders?

Cerebellar Disorders: Symptoms and Treatment

Core Clinical Presentation

Cerebellar disorders manifest with characteristic motor coordination deficits including widened-based gait, dysmetria, dysdiadochokinesia, truncal instability, dysarthria, and nystagmus—critically, these symptoms persist regardless of visual input, distinguishing them from sensory ataxia. 1

Motor Symptoms

• Gait abnormalities: Staggering, broad-based stance with increased variability; tandem gait is typically impaired 2, 3
• Limb ataxia: Dysmetria manifests as overshooting or undershooting during finger-to-nose and heel-to-shin testing 1
• Dysdiadochokinesia: Inability to perform rapid alternating movements 1
• Dyssynergia: Loss of coordinated multi-joint movements 1
• Tremor: Action tremor, postural tremor, and kinetic tremor variants 4
• Hypotonia: Reduced muscle tone, though cerebellar rigidity can also occur 4

Oculomotor Symptoms

• Nystagmus: Eye instability and abnormal eye movements 3
• Ocular dysmetria: Saccadic overshooting 1
• Impaired smooth pursuit and vestibulo-ocular reflex dysfunction 3
• Ophthalmoplegia: May occur in specific syndromes like Miller Fisher syndrome (triad of ataxia, areflexia, and ophthalmoplegia) 1

Speech and Cognitive Symptoms

• Ataxic dysarthria: Scanning or explosive speech with staccato quality and slurred articulation 1, 4
• Cerebellar mutism: Most common in children after midline cerebellar tumor resection 4
• Cognitive impairments: Executive dysfunction, visual-spatial processing deficits, linguistic difficulties, and affective dysregulation (Schmahmann's syndrome) 3

Truncal and Postural Symptoms

• Truncal ataxia: Difficulty maintaining posture, particularly prominent with cerebellar vermian pathology 1, 5
• Increased postural sway with hypermetric responses to perturbations 2

Critical Diagnostic Distinctions

The key distinguishing feature: unsteadiness does NOT significantly worsen with eye closure in cerebellar ataxia, unlike sensory ataxia. 1

• Negative Romberg test: Worsening with eyes closed suggests sensory ataxia involving dorsal columns rather than cerebellar pathology 1
• Vestibular dysfunction: Lurching gait triggered by head rotation indicates vestibular rather than cerebellar dysfunction 1

Common Diagnostic Pitfalls to Avoid

• Mistaking weakness or hypotonia for ataxia, particularly in children 1
• Missing "pseudoataxia" from functional disorders that mimic organic cerebellar disease 1
• Overlooking associated spinal cord signs (motor spasticity, sensory ataxia) that warrant spine imaging in addition to brain imaging 1

Diagnostic Workup

MRI of the head without IV contrast is the preferred initial imaging modality for evaluating cerebellar disorders. 1, 5

• MRI findings: Volume loss in cerebellum/brainstem, signal alterations, and patterns suggesting specific ataxia subtypes 5
• Contrast-enhanced MRI: Should be added if inflammatory or neoplastic causes are suspected 1
• Advanced MRI techniques: Diffusion-weighted imaging and spectroscopy help detect early changes and distinguish between ataxia subtypes 1, 5

Physical Examination Specifics

• Monitor for pupillary abnormalities suggesting drug/toxin ingestion versus third nerve compression 1
• Assess for torticollis or resistance to head/neck motion indicating craniocervical junction pathology, cord compression, or posterior fossa tumor 1
• Look for telangiectasias suggesting ataxia-telangiectasia 1

Recognition of Acute Deterioration

Cerebellar Infarction with Swelling

Deterioration from cerebellar infarcts presents with brainstem compression signs: pupillary anisocoria, pinpoint pupils, loss of oculocephalic responses, bradycardia, irregular breathing patterns, and sudden apnea. 6

• Clinical deterioration criteria: Brainstem compression signs, obstructive hydrocephalus, depressed consciousness, Glasgow Coma Scale <12 on admission, or decline ≥2 points 6
• Radiographic deterioration: Fourth ventricular compression and hydrocephalus 6
• Temporal patterns: Headache with truncal ataxia and dysmetria suggests acute cerebellitis; altered consciousness may indicate increased intracranial pressure or herniation 1

Monitoring Recommendations

• Frequent monitoring of level of arousal and new brainstem signs in patients with cerebellar stroke at high risk for deterioration (Class I; Level of Evidence C) 6

Treatment Approaches

Acute Management of Cerebellar Infarction with Swelling

Osmotic therapy for patients with clinical deterioration from cerebral swelling is reasonable (Class IIa; Level of Evidence C). 6

• Initial measures: Elevate head of bed to 30° 6
• Osmotic agents: Mannitol and hypertonic saline (3%, 7.5%, 23% concentrations) work through osmotic gradient, drawing water from neurons into arteries 6
• Thrombosis prophylaxis: Subcutaneous heparin or low-molecular-weight heparin is necessary to prevent deep venous thrombosis, even with hemorrhagic conversion or early edema on CT 6
• NOT recommended: Hypothermia, barbiturates, and corticosteroids have insufficient data and are not recommended (Class III; Level of Evidence C) 6
• Seizure management: Seizures are uncommon; no evidence supports prophylaxis, but prolonged EEG monitoring may be needed for fluctuating consciousness 6

Pharmacologic Management for Chronic Cerebellar Ataxia

Evidence for pharmacologic management is limited, though aminopyridines reduce attacks in episodic ataxias and may improve gait ataxia in other conditions. 2

Rehabilitation Interventions

Intensive exercises targeting balance and coordination lead to improvements in balance and walking, but require ongoing training to maintain effects. 2

• Balance training programs improve stability 1
• Postural training improves trunk control 1
• Task-oriented upper limb training improves reaching and fine motor control 1
• Prescription of assistive devices and orthoses improves balance and mobility 1

Supportive Management

• Walking aids, orthoses, specialized footwear, and seating may be required for severe cases 2
• Noninvasive brain stimulation of the cerebellum may become a useful adjunct to therapy in the future 2
• Management of associated conditions: Address autonomic dysfunction and sleep disorders 5

Underlying Cause Identification

Identification of the underlying cause is crucial for developing an effective management plan. 5

• Genetic/inherited disorders: Autosomal dominant spinocerebellar ataxias, autosomal recessive conditions 5
• Acquired causes: Toxic/nutritional factors, immune-mediated conditions, infectious diseases, neurodegenerative disorders, vascular diseases 5