Ataxia, Acute Cerebellar

Key Features

• Most common cause of acute childhood ataxia

• Accounts for about 40% of all cases

• Occurs most commonly in children aged 2–6 years

• Symptoms may include refusal to walk due to ataxia, in addition to sudden development of a wide-based, drunken gait

• Families may not report unsteadiness of arm movements, ataxia of the trunk, or dysarthria, but these symptoms are essential to localization

• Serious causes include cns infections and intracranial mass lesions

Clinical Findings

• Onset is abrupt

• Evolution of symptoms is rapid

• In about 70% of patients, a prodromal illness occurs with fever, respiratory or gastrointestinal symptoms, or an exanthem within 3 weeks of onset.

• Associated viral infections include varicella, rubeola, mumps, echovirus infections, poliomyelitis, infectious mononucleosis, and influenza.

• Bacterial infections such as scarlet fever and salmonellosis have also been incriminated.

• Mental status is normal in these patients, as is sensory and reflex testing.

Diagnosis

• Cerebrospinal fluid opening pressure, protein, and glucose levels are typically normal, though a mild pleocytosis with lymphocytic predominance can be seen

• Any significant elevation in white blood count and protein level should prompt an evaluation for meningitis or encephalitis

• CT and MRI scans are typically normal

• Occasionally focal cerebellar or cerebellopontine demyelinating lesions or enhancement of the meninges can be seen

• Decreased regional blood flow in the cerebellum on SPECT without abnormal foci on MRI of the brain has also been reported

Treatment

• Supportive

• Intravenous immunoglobulin (IVIg) has been used

• Corticosteroid use does not result in any improvement

• About 80–90% of patients recover without sequelae within 6–8 weeks, though some may demonstrate residual behavioral changes, learning problems, eye movement abnormalities, and speech problems