Postinfectious Cerebellar Syndrome With Paraneoplastic Antibodies: An Association or Coincidence?

Cerebellar ataxia has a very broad differential diagnosis in adults, including paraneoplastic and postinfectious etiologies. We report a case of a 56-year-old male presented with right-sided cerebellar dysfunction preceded by fever and headache. He was diagnosed with subacute postinfectious cerebellar ataxia. Blood serology showed the presence of anti-amphiphysin and anti-Ri (ANNA-2, antineuronal nuclear autoantibody type 2) antibodies, which have a known association with cerebellar syndrome. The patient subsequently improved with the steroids. Although no evidence of an underlying tumor was found in the patient, the presence of the paraneoplastic antibodies remains a mystery. We suggest a probable association of these antibodies with the postinfectious cerebellar syndrome.