Patterns of sensory loss
Nystagmus: This is usually horizontal and the fast phase is towards the side of the lesion.
Dysarthria: Scanning speech, which is when the speech is heard syllable by syllable. Ask the patient to say ‘British Constitution’ or ‘West Register Street’. It occurs when both lateral lobes are affected.
Rebound: Hands and arms outstretched, eyes closed, push down each hand in turn, and look for rebound (overshooting).
Finger-nose test: Intention tremor and past-pointing. Dysdiadochokinesis: Tapping alternately with the palmar and dorsal aspects of the hand is poor.
Heel-shin test: Poorly performed, the patient is unable to keep heel on shin.
Truncal ataxia: Also called central ataxia. Test the ability of the patient to sit on the edge of the bed with their arms crossed.
Gait: Wide-based gait, with a tendency to drift towards the side of the lesion. Stopping and turning is difficult. If there is no obvious abnormality, ask the patient to walk heel to toe. Even a mild cerebellar problem makes this very difficult.
Causes include the following:
· Multiple sclerosis Trauma
· Endocrine: Hypothyroidism.
· Vascular: Cerebellar haemorrhage, cerebellar ischaemic stroke.
· Drugs: Phenytoin, carbamazepine.
· Metabolic: Alcohol (acute, reversible or chronic degeneration)
· Neoplastic: Tumour, paraneoplastic syndrome, e.g. lung carcinoma
· Congenital: Arnold–Chiari malformation, Friedreich’s ataxia