Recurrent Demyelination and Remyelination in 37 Young Bengal Cats with Polyneuropathy

Background: With the exception of diabetic neuropathy, polyneuropathy associated with hyperchylomicronemia, and a few inherited polyneuropathies, peripheral neuropathies are poorly characterized in cats. A chronic polyneuropathy is described in a cohort of young Bengal cats. Objective: To characterize the clinical and histopathological features of a chronic-relapsing peripheral neuropathy in young Bengal cats. Animals: Thirty-seven young Bengal cats with clinical weakness consistent with peripheral neuropathy. Methods: Bengal cats were included in this study after a diagnosis of polyneuropathy was confirmed by muscle and peripheral nerve biopsy specimens. Pathological changes were characterized at the light and electron microscopic level and by morphometry. Clinical information and long-term outcome from case records of Bengal cats with histologically confirmed peripheral neuropathy were then assessed. Results: Nerve fiber loss within distal intramuscular nerve branches was a consistent finding in young Bengal cats with polyneuropathy. The most common abnormalities in peripheral nerve biopsies included inappropriately thin myelin sheaths and thinly myelinated fibers surrounded by supernumerary Schwann cell processes, indicative of repeated cycles of demyelination and remyelination. Recovery was common. Response to treatment could not be determined. Conclusions and Clinical Importance: A chronic-relapsing form of polyneuropathy associated primarily with episodes of demyelination and remyelination was identified in young Bengal cats. The prognosis for recovery is good, although relapses are possible and there can be residual motor deficits.