Cerebellar Syndrome

Relevant physical signs

• Inspection
  • Scars to suggest previous decompression / tumour resection
• Cranial nerves
  • Kayser-Fleisher rings (Wilson’s disease)
  • Multi-directional nystagmus
  • Internuclear ophthalmoplegia (demyelination)
  • Restriction of extra-ocular movements (Miller-Fisher syndrome)
  • Relative afferent pupillary defect (demyelination)
  • Ipsilateral loss of facial sensation (lateral medullary syndrome)
  • Ipsilateral Horner’s syndrome (lateral medullary syndrome)
  • Ipsilateral lower VII and VIII palsy (cerebellopontine angle)
  • Staccato, scanning speech
    • Say “baby hippopotamus” and “West Register Street”
• Upper limbs
  • Holmes rebound phenomenon
  • Truncal ataxia (usually points to cerebellar vermis)
  • Intention tremor
  • Dysmetria
  • Dysdiadochokinesis
  • Parkinsonism (multiple system atrophy)
    • Lead-pipe rigidity
    • Cogwheeling
    • Resting tremor
  • Arreflexia (Miller-Fisher syndrome)
  • Power (if the patient has an ataxic hemiparesis)
  • Contralateral (to the cerebellar signs) spinothalamic sensory loss (lateral medullary syndrome)
• Lower limbs
  • Toe clawing, pes cavus (Friedrich’s ataxia)
  • Dysmetria (toe to finger test)
  • Dyssynergia (heel-shin test)
  • Dysmetria (foot tapping test)
  • Pendular jerks
  • Ataxic gait, tends to veer towards the side of the lesion
• Cardiovascular screening (stroke)
  • Pulse (atrial fibrillation)
  • Carotid bruits (carotid artery stenosis)
  • Diabetic dermopathy
• Chronic alcoholism (bilateral cerebellar syndrome)
  • Stigmata of chronic liver disease
  • Dupuytren’s contracture
  • Parotid enlargement

Differential diagnosis

• Unilateral
  • Ischaemic
    • Stroke within the cerebellar hemisphere
    • Stroke causing a lateral medullary syndrome
      • Ipsilateral Horner’s, facial sensory loss with contralateral spinothalamic loss
    • Lacunar infarct (ataxic hemiparesis)
  • Neoplastic
    • Cerebellopontine angle tumour
    • Primary brain tumour within the cerebellum
    • Cerebellar metastases
    • Neurofibromatosis type 2
• Bilateral
  • Hereditary
    • Friedrich’s ataxia
      • Autosomal recessive
      • Trinucleotide (GAA) expansion repeat in the frataxin gene
      • Clinical features
        • Progressive cerebellar ataxia
        • Hyporeflexia / arreflexia
        • Distal weakness, initially involving the lower limbs
        • Dorsal column loss, initially distal
        • Dysphagia
        • Reduced visual acuity
        • Sensorineural hearing loss
        • Kyphoscoliosis
        • Pes cavus
        • Urinary incontinence
        • Cardiomyopathy
        • Diabetes mellitus
    • Spinocerebellar ataxia
      • Usually autosomal dominant
      • Some involve trinucleotide expansion CAG repeats
      • Clinical features
        • Usually presents in third or fourth decade
        • Progressive cerebellar ataxia
        • Dysarthria, bulbar palsy
        • May have slow saccades and saccadic pursuit
        • May have lid retraction
        • Increased tone
        • Hyperreflexia
        • Extensor plantar responses
        • May have peripheral neuropathy causing fasciculations and wasting
    • Wilson’s disease
      • Autosomal recessive
      • Clinical features
        • Tremor
        • Ataxia
        • Psychiatric disorders
        • Chronic liver disease
    • Ataxia telangiectasia
      • Autosomal recessive
      • Telangiectasia on face, ears, conjunctiva and skin creases
      • Associated IgA deficiency with recurrent chest infections
      • Associated lymphoreticular malignancy
    • Arnold-Chiari malformation
  • Inflammatory
    • Demyelination (multiple sclerosis)
    • Miller-Fisher syndrome
    • Degenerative
      • Multiple system atrophy
  • Drug-induced
    • Alcohol-induced cerebellar degeneration
    • Wernicke’s encephalopathy (ophthalmoplegia, ataxia and confusion)
    • Phenytoin
    • Lithium
    • Carbamezapine
    • Phenobarbitone
  • Neoplastic
    • Bilateral cerebellopontine angle tumours
    • von Hippel Lindau syndrome
    • Neurofibromatosis type 2
    • Paraneoplastic phenomenon (usually lung, breast or ovarian carcinoma)
  • Vascular
    • Bilateral cerebellar strokes

Investigations

• Magnetic resonance imaging (posterior fossa is bony, hence computed tomography may be sub-optimal) of the brain to look for strokes, space-occupying lesions and cerebellar degeneration
• In patients with a family history:
  • Genetic testing for trinucleotide expansion repeat in frataxin gene
  • Genetic testing for disabling mutations in the ATM gene (ataxia telangiectasia)
  • Genetic testing for SCA genes
  • Serum caeruplasmin (low) and 24h urinary copper excretion (high) for Wilson’s disease
• Consider lumbar puncture (Miller-Fisher)
  • Normal cell differential count with elevated CSF protein (albuminocytologic dissociation)
• Serology
  • Anti-GQ1b (ganglioside) antibodies in Miller-Fisher syndrome
  • Anti-Yo (Purkinje cell) antibodies in paraneoplastic syndrome (usually gynaecological and breast)
  • Anti-Hu (neuronal nuclear) antibodies in paraneoplastic syndrome (other malignancies)
• Drug levels if drug-induced cerebellar syndrome suspected
• If stroke, look for underlying cause
  • Trans-cranial Doppler
  • Doppler of the carotid arteries
  • Trans-thoracic echocardiogram to look for intracardiac thrombus
  • Holter monitoring to detect paroxysmal atrial fibrillation
  • Screening for cardiovascular risk factors (HbA1c, LPM)
• Age-appropriate malignancy screening to look for underlying malignancy

Management

• Multidisciplinary team approach
• Physiotherapy, occupational therapy to maximize and preserve function
• Consider genetic counselling for hereditary ataxias
• Alcohol cessation and thiamine supplementation
• Withdrawal of the offending drug
• Consider referral to neurosurgery for excision of space-occupying lesion
• Antiplatelet, statin and gastric protection for stroke
• Consider Madopar for multiple system atrophy, but may not work
• Treat underlying malignancy
• Intravenous immunoglobulin or plasma exchange for Miller-Fisher syndrome