Demyelinating polyneuropathy with focally folded myelin sheaths in a family of M

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J Neurol Sci. 2008 Sep 20.

Demyelinating polyneuropathy with focally folded myelin sheaths in a

family of Miniature Schnauzer dogs.

Vanhaesebrouck AE, Couturier J, Cauzinille L, Mizisin AP, Shelton GD,

Granger N.

National Veterinary School of Alfort, Maisons-Alfort, France.

A spontaneous demyelinating polyneuropathy in two young Miniature

Schnauzer dogs was characterized clinically, electrophysiologically

and histopathologically. Both dogs were related and a third dog,

belonging to the same family, had similar clinical signs.

On presentation, clinical signs were restricted to respiratory

dysfunction. Electrophysiological tests showed a dramatic decrease in

both motor and sensory nerve conduction velocities. Microscopic

examination of peripheral nerve biopsies (light and electron

microscopy, teased nerve fibers), showed that this neuropathy was

characterized by segmental demyelination and focally folded myelin

sheaths.

Various clinical syndromes associated with tomacula or focal

thickening of the myelin sheath of the peripheral nerves have been

described in humans and shown to be caused by gene mutations

affecting the myelin proteins, such as the hereditary neuropathy with

liability to pressure palsies or the demyelinating forms of Charcot-

Marie-Tooth disease.

In animals, a tomaculous neuropathy has been reported in cattle and

chickens but not in carnivores. Here we report a demyelinating

peripheral neuropathy with tomacula in two Miniature Schnauzer dogs.