cerebellitis

Cerebellitis is inflammation of the cerebellum, the part of the brain that coordinates movement and balance. It can arise from infectious, autoimmune post-infectious, inflammatory, or other processes and commonly presents with acute or subacute cerebellar signs.

The most prominent symptom is ataxia, with impaired coordination of limbs, gait disturbances, and difficulty with rapid alternating movements. Other findings may include dysmetria, intention tremor, dysdiadochokinesia, nystagmus, slurred speech (dysarthria), headache, nausea, and vomiting. Truncal ataxia may be especially noticeable in children.

Causes and pathophysiology vary. In children, acute cerebellitis is often post-infectious or immune-mediated and can follow varicella or other viral illnesses. Infectious cerebellitis can be due to viruses such as varicella, influenza, enteroviruses, or EBV, and may be associated with meningitis or encephalitis. Autoimmune or inflammatory mechanisms, including post-infectious cerebellitis and other inflammatory disorders, can also contribute. Less commonly, cerebellitis occurs in the context of vasculitis, demyelinating disease, paraneoplastic processes, or opportunistic infections in immunocompromised individuals.

Diagnosis relies on clinical assessment supported by imaging and laboratory studies. Magnetic resonance imaging (MRI) of the brain is preferred and may show cerebellar edema or inflammatory changes; computed tomography (CT) can be normal early. Lumbar puncture with CSF analysis and targeted blood tests help identify infectious or autoimmune etiologies and exclude stroke, tumor, intoxication, or metabolic causes.

Management focuses on treating the underlying cause and providing supportive care. Antiviral or antibacterial therapy is used when an infection is identified; corticosteroids, IVIG, or plasmapheresis may be considered for autoimmune or inflammatory cerebellitis. Physical therapy and supportive measures address ataxia and balance. Prognosis is generally favorable in children, with many recovering within weeks to months; adults may recover more slowly and with greater risk of residual ataxia.