title: Severe cranial nerve involvement in longstanding demyelinating polyneuropathy: a clinicopathologic correlation.
abstract: Onion bulb formations involving cranial nerves are an unusual pathologic feature. We report the postmortem neuropathologic findings in a 69-year-old man with a longstanding neuropathy characterized by progressive muscle weakness, sensory ataxia and multiple cranial nerve abnormalities. Electrodiagnostic testing disclosed features of an acquired demyelinating polyneuropathy. Treatment with corticosteroids and plasmapheresis resulted in no change in his neurologic status, and the patient died after repeated episodes of pneumonia and sepsis. Autopsy showed widespread onion bulb formation in cranial nerves III, IV, V, VI, X, XI and XII, anterior and posterior spinal nerve roots, dorsal root ganglia and multiple peripheral nerves, some of which also had foci of epineurial perivascular inflammation. Muscle sections revealed severe neurogenic atrophy. This case demonstrates that, in longstanding acquired demyelinating neuropathy, the cranial nerves also undergo repetitive cycles of demyelination and remyelination resulting in severe weakness of the bulbar musculature and histologic features of hypertrophic neuropathy.
authors.affiliation: Department of Pathology, University of Massachusetts Medical Center, Worcester 01655, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: McCann
authors.forename: T W
authors.initials: TW
authors.lastname: Smith
authors.forename: D A
authors.initials: DA
authors.lastname: Chad
authors.forename: J
authors.initials: J
authors.lastname: Sargent
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology; D002908:Chronic Disease; D003391:Cranial Nerves / Q000473:pathology*; D003711:Demyelinating Diseases / Q000473:pathology*; D005911:Gliosis / Q000473:pathology; D006801:Humans; D008297:Male