Post viral cerebellar ataxia is a clinical syndrome defined by the rapid onset of cerebellar dysfunction, which manifests primarily as gait disturbance and incoordination. It typically occurs in association with a benign viral illness or vaccination. Although influenza virus was known as a causative agents of post viral cerebellar ataxia in child or young adult, the cases of post viral cerebellar ataxia after influenza infection in the elderly have rarely been reported. We report the case of a 71-year-old patient who had post viral cerebellar ataxia after type B influenza infection.
A 71-year-old male patient was admitted at our hospital with a 2-months history of limb and gait ataxia. Two months before coming to the hospital, he got type B influenza infection and presented symptoms of fever, sore throat, myalgia. The symptoms had been improved in 2 weeks, however he developed gait ataxia and looked staggering when he walked. One month later, he suddenly appeared unable to stand and walk, and he also complained severe dizziness, nausea, vomiting and dysphagia. He had no history of any medical or neurological illness. On the neurological examination at admission, he was alert and well oriented. Cranial nerve examination was normal without nystagmus. Cerebellar function test showed remarkable dysmetria and dysdiadochokinesia especially, in the left upper and lower extremities. Gait ataxia was severe enough for him not to walk by himself. Finger-to-nose test, heel-to-shin test found were positive, but, because standing was unable, Romberg's test and tandem gait test could not be performed. Motor power of both lower extremities on manual muscle test was checked as the normal grade but loss of deep tendon reflexes. Electromyography was performed to exclude peripheral neuropathy, but there were no obvious abnormal findings. Blood tests revealed no specific abnormal findings. The serological tests for detection of antibody were all negative. Cerebrospinal fluid examination revealed a cell count of 6 white blood cells with 24% neutrophils, protein 39 mg/dL, glucose 67 mg/dL (serum glucose 95 mg/dL). There was no abnormality on brain magnetic resonance imaging with contrast enhancement. The clinical features and laboratory data led to a diagnosis of post viral cerebellar ataxia. His symptoms improved after treated with steroids and IVIG. He was able to walk and discharged to home.
Most Influenza infection is known to cause post viral cerebellar ataxia in children, but we have found it could be rare in elderly as well. |
