Fibrinoid leukodystrophy

From Dog
Revision as of 01:42, 19 November 2012 by WikiSysop (talk | contribs)
White matter EM study, showing enlarged astrocyte with a cytoplasm densely packed with RF filaments[1]

Fibronioid leukodystrophy is a rare genetic disease of dogs characterised by localized disease of the white matter of the cerebellum and brain stem.

This disease may occur sporadically or in litters with a possible genetic underpinning. The condition in dogs is morphologically identical to human Alexander's Disease.

Clinical symptoms include weight loss, mental depression, anorexia, generalized weakness and vomiting. initial neurological signs are inconsistent but invariably progress to include progressive tetraparesis and tremors, particularly of the hind limbs, followed by posterior paresis and tetraparesis.

A common complication is megaesophagus, which has been diagnosed in the Burnese Mountain Dog[2] and French Bulldog[3].

Hematology, urinalysis and CSF analysis are often unrewarding.

Diagnosis usually requires pre- or postmortem brain biopsy. histologically, this disease appears as a diffuse degenerative myeloencephalopathy[4], affecting only the white matter of the brain.

Immunohistochemistry is required for detection of glial fibrillary acidic protein (Rosenthal fibers throughout the white matter), allowing for a definitive diagnosis. Dystrophic astrocytes, enlarged with abundant RF particles, is characteristic of this disease.

A differential diagnosis include canine distemper virus.

Treatment responses to prednisolone are poor and the disease invariably progresses, requiring euthanasia.

References

  1. Alemañ N et al (2006) Rosenthal fiber encephalopathy in a dog resembling Alexander disease in humans. Vet Pathol 43(6):1025-1028
  2. Weissenböck, H et al (1996) Alexander's disease in a Bernese mountain dog. Acta Neuropathol 91(2):200-204
  3. Ito T et al (2010) Fibrinoid leukodystrophy (Alexander's disease-like disorder) in a young adult French bulldog. J Vet Med Sci 72(10):1387-1390
  4. Cox NR et al (1986) Myeloencephalopathy resembling Alexander's disease in a Scottish terrier dog. Acta Neuropathol 71(1-2):163-166