Unilateral cerebellar lesions cause ipsilateral signs.

Useful and well-known mnemonic to remember symptoms of cerebellar disease is DANISH:

• D - Dysdiadochokinesia, Dysmetria (past-pointing), patients may appear 'Drunk'
• A - Ataxia (limb, truncal)
• N - Nystamus (horizontal = ipsilateral hemisphere)
• I - Intention tremour
• S - Slurred staccato speech, Scanning dysarthria
• H - Hypotonia

Causes

• Friedreich's ataxia, ataxic telangiectasia
• neoplastic: cerebellar haemangioma
• stroke
• alcohol
• multiple sclerosis
• hypothyroidism
• drugs: phenytoin, lead poisoning
• paraneoplastic e.g. secondary to lung cancer