Cryptogenic sensory and sensorimotor polyneuropathies.

Chronic sensory or sensorimotor polyneuropathy is a common clinical problem referred to neurologists. Even with modern diagnostic approaches, up to one-third of them will remain unclassified. Recent studies have provided insight into their clinical spectrum and course. The age of onset tends to be in the sixth to seventh decade of life. Symptoms progress slowly, and most patients present with paresthesias or pain. Cryptogenic polyneuropathies are almost exclusively axonal on clinical, electrophysiologic, and histologic grounds. Overall, the prognosis is favorable, and only a small minority of patients develop significant motor disability or physical incapacitation. Progression to a nonambulatory state essentially never occurs. Successful management should focus on rational pharmacotherapy for painful paresthesias combined with patient education and reassurance.