Lumbosacral plexus neuritis.

We studied four patients with neurologic disorders of the lumbosacral plexus. Except for location of symptoms, the disorder confirmed to criteria established for the clinical diagnosis of brachial plexus neuritis. Acute onset of pain in one or both legs was followed by weakness, loss of stretch reflexes, and sometimes atrophy of affected muscles. The disorder affected in individual nerves or parts of the plexus. Gradual recovery occurred in all four patients.