Poststreptococcal acute disseminated encephalomyelitis with basal ganglia involvement and auto-reactive antibasal ganglia antibodies

Antibasal ganglia antibodies (ABGA) are associated with Sydenham's chorea a nd pediatric autoimmune neuropsychiatric disorders associated with streptoc occal infections. We present 10 patients with acute disseminated encephalom yelitis (ADEM) associated with Group A beta hemolytic streptococcal infecti on. The clinical phenotype was novel, with 50% having a dystonic extrapyram idal movement disorder, and 70% a behavioral syndrome. None of the patients had rheumatic fever or Sydenham's chorea. Enzyme-linked immunosorbent assa y, Western immunoblotting, and immunohistochemistry were used to detect ABG A. Neurological (n = 40) and streptococcal (n = 40) controls were used for comparison. Enzyme-linked immunosorbent assay results showed significantly elevated ABGA in the patients with poststreptococcal ADEM. Western immunobl otting demonstrated ABGA reactivity to three dominant protein bands of 60, 67, or 80 kDa; a finding not reproduced in controls. Fluorescent immunohist ochemistry demonstrated specific binding to large striatal neurones, which was not seen in controls. Streptococcal serology was also significantly ele vated in the poststreptococcal ADEM group compared with neurological contro ls. Magnetic resonance imaging studies showed hyperintense basal ganglia in 80% of patients with poststreptococcal ADEM, compared to 18% of patients w ith non-streptococcal ADEM. These findings support a new subgroup of postin fectious autoimmune inflammatory disorders associated with Group A beta hem olytic streptococcus, abnormal basal ganglia imaging, and elevated ABGA.