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Lewis-Sumner Syndrome

In 1982, Lewis and colleagues described five patients with a chronic, acquired, asymmetric sensorimotor demyelinating polyneuropathy that clinically resembled a mononeuritis multiplex.[149] Subsequently, many similar patients have been described.[150–154] The syndrome has been given various names, most commonly Lewis-Sumner syndrome and multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy.

Diagnosis and Evaluation

Patients have a slowly progressive course, commonly over many years. The upper extremities are usually involved before the lower extremities. Both weakness and numbness may be present, and the pattern of involvement is asymmetric, usually in the distribution of discrete nerves such as one sees in a mononeuritis multiplex. Pain is more common than in MMN. Cranial neuropathies may occur but are rare. Reflexes are usually decreased in an asymmetric multifocal manner, but rarely are completely absent.

Blood and urine tests are usually the same as …