chronic inflammatory demyelinating polyneuropathy

an uncommon, acquired, demyelinating sensorimotor polyneuropathy, clinically characterized by insidious onset, slow evolution, (either steady progression or stepwise), and chronic course; symmetric weakness is a predominant symptom, often involving proximal leg muscles, accompanied by paresthesias, but not pain; CSF examination shows elevated protein, whereas electrodiagnostic studies reveal evidence of a demyelinating process, primarily conduction slowing rather than block; sometimes responds to prednisone.