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.

Asymmetrical polyneuropathy with a stepwise progressive course and well-demarcated areas of demyelination

“…Other examples of CIDP with focal involvement 23 demonstrate that the presenting features may be quite variable. As reported in a few patients with CIDP, our patient also had cranial nerve involvement 18,26 and nonspecific MRI white matter lesions. 19,26 The alterations of the MNCVs with marked temporal dispersion were consistent with the demyelination found in the acquired demyelinating neuropathies.…”

Relapse with Dysphagia in a Case of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

“…A small number of cases of CN involvement in patients with CIDP have been described (3). CIDP with involvement of CNs IX and/or X is infrequent, with clinical features reported in only three cases.…”

Spinal and cranial hypertrophic neuropathy in multiple sclerosis

“…Most patients with coexistent CNS and PNS demyelination do not have hypertrophic neuropathy. Massive spinal nerve root or cranial nerve hypertrophy is a rare, but well‐described, occurrence in patients with pure CIDP without coexistent CNS demyelination 4, 8, 11, 16. The nerve enlargement is due to extensive onion‐bulb formation 10.…”