Super-refractory status epilepticus due to anti-GAD-65 autoimmune encephalitis – biphasic presentations with discognitive crisis with generalization and posterior focal myoclonus

Abstract

Introduction: Status epilepticus (SE) is a neurologic emergency and many causes should be investigated, such as autoimmune encephalitis. A patient will be described, with high levels of antibodies against 65kDa glutamic acid decarboxylase (GAD), an intracellular enzyme, which developed into super-refractory status. Objective: To emphasize the importance of immunologic mechanisms on the SE. Patient and methods: A 19-year old healthy female suddenly presented behaviour changes and recurrent generalized tonic-clonic crisis. The cerebrospinal fluid investigation was normal, brain MRI showed non-specific image in the white matter right hemisphere. The anti-GAD antibodies, obtained in serum, were with high levels (1960nmol/l). Continuous electroencephalogram (EEG) revealed moderate disorganization, epileptiform paroxysms in the right anterior frontotemporal region and rhythmic delta activity with varied frequencies and amplitudes suggestive of ictal discharges. Different types anticonvulsants drugs were used to control status without success. She recovered 2 months later after methylprednisolone and immunoglobulin. The patient initiated with focal myoclonus in the right upper limb after five months from hospital discharge. We have obtained patient and/or Institutional Review Board (IRB) approval, as necessary. Results: Most described cases of anti-GAD autoimmune encephalitis are presented as limbic encephalitis. Our case report shows a super-refratary status epilepticus and with partial relief of immunotherapy. Conclusion: The use of immunotherapy is essential in this case. Current studies are few to determine the best therapeutic approach.