Acute ataxia in children: Common causes and yield of diagnostic work-up in the era of varicella vaccination.

We aimed to identify the most common causes of acute ataxia in children in the era of widespread varicella vaccination and the yield of commonly used diagnostic work-up. This retrospective study reviewed the medical records of children who presented with ataxia of less than 72 h duration, over the last 12 years. Associated signs and symptoms, laboratory, EEG and neuroimaging studies, final diagnosis and clinical findings at discharge and during follow-up were studied. A total of 58 patients (35 boys, 23 girls), mean age 4.9 ± 3.8 years, were enrolled. The most common etiology of acute ataxia in our study was post-infectious acute cerebellar ataxia (50%). Children diagnosed with post-infectious acute cerebellar ataxia were significantly younger (3.48 ± 2.23 vs. 6.5 ± 3.1 years, p = 0.01), as compared with children diagnosed with infection and acute disseminated encephalomyelitis. 86% of children with post-infectious cerebellar ataxia were younger than 5 years of age. The abnormality yield of work-up studies performed in our cohort was 39% for lumbar puncture, 36% for EEG, 7% for CT scan. MRI was done in children who showed extra cerebellar signs, when vascular or demyelinating diseases were suspected and in children with prolonged symptoms and was abnormal in 8 (14%) children. We conclude that post-infectious acute cerebellar ataxia remains the most common cause of acute ataxia in children. Although lumbar puncture and neuroimaging should be considered in all children with acute cerebellar ataxia, younger children with a history of previous viral illness and no extra cerebellar signs and symptoms may benefit from watchful waiting.