Acute sensory neuronopathy with preserved SEPs and long-latency reflexes

A case of spontaneous acute sensory neuronopathy is described in a previously healthy 19-year-old male. He had marked sensory ataxia with relative sparing of cutaneous sensation. There was no recovery over 4 years. Sural nerve biopsy showed modest axonal loss. Sensory evoked potentials were mildly abnormal in the face of absent sensory nerve action potentials. The long-latency (R2) reflex was preserved whereas the short-latency (R1) reflex was absent. The findings indicate that loss of large-diameter (group Ia) ganglion cells are primarily responsible for this syndrome.