Meningoencephalitis

Meningoencephalitis is inflammation of the meninges (the tissue which covers the brain and spinal cord) and brain tissue.  Inflammation can occur due to either an infection or an autoimmune reaction to one’s own tissues. Organisms which can cause brain infections in dogs and cats include bacteria, viruses, fungi, protozoa, rickettsia, and parasites.  In dogs, however, meningoencephalitis is most commonly caused by an autoimmune disorder.

Meningoencephalitis of Unknown Etiology (MUE) is the umbrella term used to refer to the suspected autoimmune brain disorders.  Disorders classified as types of MUE include Granulomatous meningoencephalitis (GME), Necrotizing meningoencephalitis (NME), and Necrotizing leukoencephalitis (NLE).  While there are some differences between these three disorders, they are lumped together because they are very difficult to distinguish in a live patient and because the treatment is similar for all disorders.

Small breed, younger to middle-aged dogs are most commonly affected by MUE.  Signs of MUE can be quite variable, so MRI and CSF (spinal tap) analysis, including detailed tests to rule-out infections of the brain, are required to reach a presumptive diagnosis.  This is adequate in most cases; however, a biopsy of the lesion is required in some patients to distinguish MUE from an infection or cancer.

Treatment of MUE is directed at dampening the immune system’s attack against the brain.  Prednisone is typically the first-line treatment; however, a second immunosuppressive is typically added to gain more long-term control of the disease.  MUE is a severe and potentially deadly disease.  If a dog survives the initial few days, however, many cases of MUE will go into remission with aggressive treatment.

You may schedule a consultation with our Neurologist by calling us at our Manchester or Newington location today.