[Chronic demyelinating polyradiculoneuropathy associated with malignant histiocytosis].

A case of malignant histiocytosis (MH) presenting with peripheral nerve involvement is described. A 67-year-old man initially noted left facial weakness on July 20, 1986. The symptom was improved within a week, however, two weeks later he noticed numbness in his fingers and a burning pain in his legs, which was followed by double vision and progressive weakness in all four limbs. On examination, he was found to have total ophthalmoparesis of the right eye and a trace of the left facial palsy. There was severe weakness of the leg muscles, as well as mild weakness of the arms. This was accompanied by wasting of his limbs. All tendon reflexes were absent. Planter responses were flexor. Although cutaneous sensation was intact, vibratory sense was markedly impaired in the legs below the knees. The sphincter function was mildly disturbed. The sedimentation rate was 32 mm/hr. The hemoglobin was 11.9 g/dl and the leukocyte count was 5,700/mm3. The platelet count fell to 60,000/mm3. Results of routine biochemical and radiological studies were unremarkable. The cerebrospinal fluid protein level was 129 mg/dl with a normal cell count. Motor nerve conduction study revealed marked reduction in amplitude of the compound muscle action potential, slow motor nerve conduction velocities and multifocal conduction blocks along the nerve trunks (the left ulnar nerve in the forearm, the bilateral tibial nerve in the lower leg). F-wave was absent or elicited with prolonged latency and with increased chrono-dispersion. Sensory nerve had normal or nearly normal conduction. EMG sampling showed an impaired interference pattern during voluntary contraction and a few denervation potentials at rest.(ABSTRACT TRUNCATED AT 250 WORDS)