Granulomatous meningoencephalitis

Granulomatous meningoencephalitis (GME) is an inflammatory disease of the central nervous system (CNS) of dogs and, rarely, cats. It is a form of meningoencephalitis. GME is likely second only to encephalitis caused by canine distemper virus as the most common cause of inflammatory disease of the canine CNS.[1] The disease is more common in female toy dogs of young and middle age. It has a rapid onset. The lesions of GME exist mainly in the white matter of the cerebrum, brainstem, cerebellum, and spinal cord.[2] The cause is only known to be noninfectious and is considered at this time to be idiopathic. Because lesions resemble those seen in allergic meningoencephalitis, GME is thought to have an immune-mediated cause, but it is also thought that the disease may be based on an abnormal response to an infectious agent.[3] One study searched for viral DNA from canine herpesvirus, canine adenovirus, and canine parvovirus in brain tissue from dogs with GME, necrotizing meningoencephalitis, and necrotizing leukoencephalitis (see below for the latter two conditions), but failed to find any.[4]

Types of GME

Diagnosis and treatment

Cerebrospinal fluid (CSF) analysis shows a large number of white blood cells. Typically small mature lymphocytes are the majority of cells seen, with monocytes and neutrophils making up the rest.[8] Definitive diagnosis is based on histopathology, either a brain biopsy or post-mortem evaluation (necropsy). A CT scan or MRI will show patchy, diffuse, or multifocal lesions. For a number of years, the basic treatment was some type of corticosteroid in combination with one or more immunosuppressive drugs, typically cytosine arabinoside and/or cyclosporine or other medications such as azathioprine, cyclophosphamide,[6] or procarbazine, of which were usually added one at a time to the corticosteroid until a successful combination was found. There is evidence that treatment with radiation therapy for focal GME provides the longest periods of remission.[1]

Pug Dog encephalitis

Pug Dog encephalitis (PDE) is an idiopathic inflammatory disease primarily affecting the prosencephalon (forebrain and thalamus). It is also known as necrotizing meningoencephalitis. The disease may be inherited in Pugs and Maltese and has been diagnosed in other breeds as well (Yorkies, Chihuahuas).[6] It differs in pathology from GME by more tissue breakdown and increased eosinophils (white blood cells). CSF analysis is also unique among inflammatory CNS diseases in dogs in that the cells are predominantly lymphocytes instead of a mixed population of mononuclear cells.[9] In Maltese and Pugs there is extensive necrosis and inflammation of the gray matter of the cerebrum and subcortical white matter. The most common early symptoms are related to forebrain disease and include seizures and dementia, and later circling, head tilt, and blindness with normal pupillary light reflexes may be seen.

Necrotizing leukoencephalitis

In Yorkshire Terriers there can be severe mononuclear inflammation of the brainstem and periventricular cerebral white matter. Because the condition in this breed frequently affects only the white matter, it has been called necrotizing leukoencephalitis. Symptoms of brainstem and central vestibular disease predominate.[10]

Other types of noninfectious meningoencephalitis

See also

References

  1. 1 2 Adamo F, O'Brien R (2004). "Use of cyclosporine to treat granulomatous meningoencephalitis in three dogs". J Am Vet Med Assoc 225 (8): 1211–6, 1196. doi:10.2460/javma.2004.225.1211. PMID 15521442.
  2. Suzuki M, Uchida K, Morozumi M, Yanai T, Nakayama H, Yamaguchi R, Tateyama S (2003). "A comparative pathological study on granulomatous meningoencephalomyelitis and central malignant histiocytosis in dogs". J Vet Med Sci 65 (12): 1319–24. doi:10.1292/jvms.65.1319. PMID 14709820.
  3. 1 2 3 Vite, C.H. (2005). "Inflammatory Diseases of the Central Nervous System". Braund's Clinical Neurology in Small Animals: Localization, Diagnosis and Treatment. Retrieved 2007-02-15.
  4. Schatzberg S, Haley N, Barr S, de Lahunta A, Sharp N (2005). "Polymerase chain reaction screening for DNA viruses in paraffin-embedded brains from dogs with necrotizing meningoencephalitis, necrotizing leukoencephalitis, and granulomatous meningoencephalitis". J Vet Intern Med 19 (4): 553–9. doi:10.1892/0891-6640(2005)19[553:PCRSFD]2.0.CO;2. PMID 16095173.
  5. 1 2 "Idiopathic Inflammatory Diseases". The Merck Veterinary Manual. 2006. Retrieved 2007-02-15.
  6. 1 2 3 Ettinger, Stephen J.;Feldman, Edward C. (1995). Textbook of Veterinary Internal Medicine (4th ed.). W.B. Saunders Company. ISBN 0-7216-6795-3.
  7. Gelatt, Kirk N. (ed.) (1999). Veterinary Ophthalmology (3rd ed.). Lippincott, Williams & Wilkins. ISBN 0-683-30076-8.
  8. Vernau, William (2005). "Cerebrospinal Fluid Analysis in Dogs and Cats" (PDF). Proceedings of the 50° Congresso Nazionale Multisala SCIVAC. Retrieved 2007-02-18.
  9. Higginbotham, Michael J.; Kent, Marc; Glass, Eric N. (August 2007). "Noninfectious Inflammatory Central Nervous System Diseases in Dogs". Compendium on Continuing Education for the Practicing Veterinarian (Veterinary Learning Systems) 29 (8): 488–497.
  10. Garosi, Laurent S. (2006). "CNS inflammatory (UK) problems: The neurologist's viewpoint, clinical approach and treatment" (PDF). Proceedings of the 53° Congresso Nazionale Multisala SCIVAC. Retrieved 2007-02-18.
  11. 1 2 Chrisman, Cheryl; Clemmons, Roger; Mariani, Christopher; Platt, Simon (2003). Neurology for the Small Animal Practitioner (1st ed.). Teton New Media. ISBN 1-893441-82-2.
  12. "Meningitis and Encephalitis: Introduction". The Merck Veterinary Manual. 2006. Retrieved 2007-02-15.
This article is issued from Wikipedia - version of the Wednesday, November 11, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.