http://www.dizziness-and-balance.com/disorders/autoimmune/aibd.html Autoimmune Brain Disease (ABD) Timothy C. Hain, MD Last edited: April 4, 2010 ABD defined How common is it Diagnosis Treatment Education Index Autoimmune Brain disease or "ABD" consists of a syndrome of central nervous system which is caused by antibodies or immune cells which are attacking the brain. There is considerable overlap between autoimmune disorders that attack the ear and those that attack the brain. The immune system is complex and there are several ways that it can damage the brain. Traditional "autoimmune diseases" including Systemic Lupus Erythematosis (SLE), Sjoegren's syndrome (dry eye syndrome), Wegener's granulomatosis, and rheumatoid arthritis can cause or be associated with ABD. There are are also organ specific disorders such as Hashimoto's thyroiditis and Celiac disease (sprue) which occasionally are accompanied by ABD. In Celiac disease, antibodies have been found directed against transglutamase 2 (an autoantigen in the gut), and transglutamase 6 - an antigen independent of intesinal involvement (Hadjivassilou M, et al, 2008). Antibodies to glutamate receptors have been reported in cerebellar degenerations (Gahring et al, 1997), in patients with downbeating nystagmus (Antonini et al, 2003), and palatal myoclonus. Antibodies to GAD are also reported in "stiff person syndrome", typlified by muscular rigidity and episodic muscle spasms. Anti-GAD antibodies are also very common in diabetes. Autoimmune mechanisms have also been suggested for the opsoclonus-myoclonus syndrome (Pranzatelli 1996; Lapenna, Lochi et al. 2000; Dale 2003; Pranzatelli, Travelstead et al. 2004; Pranzatelli, Tate et al. 2005) How common is autoimmune brain disease ? ABD is rare, probably accounting for less than 1% of all cases of central disturbances. What causes autoimmune brain disease ? The cause of ABD is generally assumed to be related to either antibodies or immune cells that cause damage to the brain. There are several theories as to how these might arise, analogously to other putatative autoimmune disorders: Bystander damage: In this theory damage to the brain causes cytokines to be released which provoke, after a delay, additional immune reactions. This theory might explain the attack/remission cycle of disorders such as multiple sclerosis. Cross-reactions: In this theory, antibodies or rogue T-cells cause accidental brain damage because the brain shares common antigens with a potentially harmful substance, virus or bacteria that the body is fighting off. Intolerance: The brain, like the eye may be only an partially "immune privileged" locus, meaning that the body may not know about all of the brain antigens, and when they are released (perhaps following surgery or an infection), the body may wrongly mount an attack on the "foreign" antigen. In the eye, there is a syndrome called "sympathetic ophthalmia", where following a penetrating injury to one eye, the other eye may go blind. This theory is not presently in favor for the ABD. Genetic factors: There is increasing evidence that genetically controlled aspects of the immune system may increase or otherwise be associated with increased susceptibility to brain injury. How is the diagnosis of autoimmune brain disease made? The diagnosis is based on history, findings on physical examination, blood tests, and the results of other tests. Blood tests for autoimmune disorders include: Sed Rate and CRP ANA anti-GQ1b antibody (for eye muscle weakness) Rheumatoid Factor Complement C1Q Thyroid screen (TSH, anti-microsomal antibodies, for Hashimoto's thyroiditis and encephalopathy) anti-gliadin and anti-endomysial antibodies (for Celiac disease). anti-GAD antibodies (for stiff-person syndrome and diabetes) Anti-Purkinje cell antibodies (anti-Yo) Anti-HU, anti-Ri (for paraneoplastic antibodies to neurons) HLA testing Blood tests for conditions that resemble autoimmune disorders include: FTA (for Syphilis) Lyme titer HBA1C (for diabetes, which is often autoimmune mediated also, and is asociated with anti-GAD) How is Autoimmune Brain Disease Treated ? There are several protocols for treatment. In cases with a classic rapidly progressive impairment, a trial of steroids (Prednisone or Decadron) for 4 weeks may be tried. In persons with response to steroids, in most cases a chemotherapy type of medication such as Cytoxan or Methotrexate will be used over the long term ). Plasmapheresis or IVIG (immunoglobulin infusion) may be beneficial. Newer medications are constantly being developed for immune suppression, usually aimed at tumors of the immune system. Autoimmune brain disease is rare making it difficult to study. One can speculate that there might be effective treatments that simply have not been discovered. For example, there are numerous potential treatments that have not been tried in a formal way. Gamma globulin infusions, given monthly, is useful in numerous autoimmune disorders. This treatment is very expensive, which limits its use. Immune modulating drugs such as are used for treatment of MS (beta-interferon, alpha-inteferon, copaxone) are commonly used. Rituximab has been used in opsoclonus. Other medications that have coincidental suppression of immune responses, such as minocycline, might be tried. -------------------------------------------------------------------------------- REFERENCES: Antonini G and others. Autoantibodies to glutamic acid decarboxylase in downbeat nystagmus. J Neurol Neurosurg Psych 2003:74:998-999 Gahring LC, Rogers SW, Twyman RE. Antibodies to glutamate receptor subuint GluR2 in nonfamilial olivopontocerebellar degeneration. Neurology 1997, 48:494-500 Hadjivassiliou and others. The humoral response in the pathogenesis of gluten ataxia. Neurology 2002:58:1221-26 Hadjivassiliou and others. Autoantibodies in gluten ataxia recognize a novel neuronal transglutamase. Ann Neurol 2008:64"332-343 Pranzatelli, M. R. (1996). "The immunopharmacology of the opsoclonus-myoclonus syndrome." Clin Neuropharmacol19(1): 1-47. Pranzatelli, M. R., E. D. Tate, et al. (2005). 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