Abstract
Among 85 neuropathy patients admitted and studied in the Department of Neurology, University of Occupational and Environmental Health, Japan, from 1979 to 1990, four patients suffering from sensory ataxia are reported with special reference to their etiological and pathological conditions. All of them were classified as having immune-mediated neuropathy. The first patient, a 56-year-old woman, was diagnosed as having chronic progressive ataxic sensory neuropathy. Her symptoms became progressively worse over a nine-year period after onset, but no evidence of cancer has been revealed. The positive rheumatoid factor was the only other feature noted. The second patient, a 63-year-old woman, after extensive laboratory studies, including the biopsy of the lymphnode at the bifurcation of the bronchus in search of the cancer, was diagnosed as having subacute sensory neuropathy with small cell carcinoma of the lung. Chemotherapy was completed without subsequent obvious clinical benefits. The clinical diagnosis was confirmed on autopsy 29 months after the onset. The symptoms of the first patient were indistinguishable from those of the second patient, especially in the early clinical stage. In both patients, the proprioceptive sensations were severely affected and the disturbance of the proprioceptive sensations seemed to be almost parallel with the ataxia signs. The main site of the lesion seemed to be the neuron in the dorsal root ganglion in the first patient, as well as in the second patient who showed a marked loss of neurons in the dorsal root ganglion considered to be the primary lesion on autopsy. Two remaining patients, a 54-year-old man with residual signs of sensory ataxia and a 45-year-old man, whose superficial, vibration and position sensations were less affected disproportionately to the ataxia signs with positive Romberg's sign, were diagnosed as having an ataxic form of acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Although the lesions are usually widely distributed in the peripheral nerves, dorsal root ganglia, spinal roots and the posterior columns in AIDP, the lesions of spinal roots and dorsal root ganglia seemed to be primarily responsible for the sensory ataxia in these patients. In this report, although we studied four cases retrospectively, the neurological features of such ataxia in the peripheral nerve disorders, the nature and distribution of the lesions responsible for sensory ataxia, and the prognosis of such ataxia should be more systematically studied in future.
