[A case of chronic inflammatory demyelinating polyradiculoneuropathy with orthostatic hypotension].

A 27-year-old man was admitted to our hospital for his legs' numbness of subacute onset and discomfort while standing. No specific previous history was found and his family history was non-contributory. On admission, his general status was unremarkable except for arterial hypertension and mild tachycardia. Moderate impairment of superficial sensations and dysesthesia were noted in the distal extremities, tongue, oral cavity, and lips. Deep sensation was moderately impaired in the lower legs. Romberg sign was positive. He had mild weakness in the proximal muscles of the lower extremities. Hyporeflexia was noted in all extremities, but Achilles reflexes were absent. Pathologic reflexes were not noted. He fainted after two minute standing. On laboratory examination, serum IgM, C3, and C4 were mildly elevated. CSF protein level was prominently high without CSF pleocytosis. MCV was mildly decreased, and F wave conduction velocity was prominently decreased in the posterior tibial nerve, SCV was also mildly decreased in the right sural nerve. Needle electromyography showed mild neuropathic changes. Left sural nerve biopsy showed no abnormal finding in the myelinated and unmyelinated fibers. A 60 degree head-up tilting test caused a hypotensive attack, and Valsalva ratio was decreased. However, hand grip test and cold pressor test were normal. The response to noradrenaline infusion test and CVR-R were also normal. Muscle sympathetic activity (MSA) was recorded from the tibial nerve using a tungsten microelectrode (Iwase, et al.). His basic activity was higher and responsiveness was lower than age-matched normal controls. The regression line existed above the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)