Dados do Trabalho

Título

Anti-GABA-Ar positive antibody encephalitis as a recurring encephalitis associated with thymoma.

RESUMO

Case Presentation: A 53-year-old otherwise healthy female presented with a six-month history of cognitive and behavioral symptoms. Six months before, she presented difficulty in planning and performing multiple-step household tasks and progressive apathy. After two months, she manifested persecutory and religious delirious thoughts, sexual disinhibition and irritability. After another two months, she presented recurring focal onset seizures, starting with a speech disturbance and quickly evolving to a generalized tonic-clonic episode. Neurological exam revealed a frontal syndrome characterized by apathy, social disinhibition and executive cognitive impairment. Brain magnetic resonance imaging showed multifocal, non-enhancing, cortico subcortical T2/FLAIR signal abnormalities predominantly on frontal and temporal lobes. Cerebrospinal fluid study demonstrated the presence of oligoclonal bands despite normal cell and protein counts. A chest computed tomography revealed a thymoma that was surgically removed. Autoantibody panel confirmed the diagnosis of anti-GABA-A receptor encephalitis. The patient was treated with pulse therapy using methylprednisolone and plasmapheresis followed by cyclophosphamide, obtaining good seizure control. Six months later the disease relapsed presenting this time also with hemiparesis. Rituximab was administered, seizure control was once more obtained but the patient remains to this day with important behavioral symptoms.

Discussion: Anti-GABA-Ar encephalitis can be one of the thymoma associated paraneoplastic encephalitis. Seizures, cognitive impairment, decreased level of consciousness, altered behavior and movement disorders are the most frequent symptoms. Distinctive multifocal cortical-subcortical T2/FLAIR MR abnormalities provide an important clue to the diagnosis, since they rarely occur in other autoimmune encephalitis. The disorder is severe but most patients respond to treatment. However, up to a third of patients may relapse and recurrent disease may occur even after surgical removal of the thymoma.

Final comments: Anti-GABA-Ar positive encephalitis should be considered in patients with rapidly progressive cognitive decline, particularly in the setting of thymoma. Relapse may occur even after the removal of the associated tumor.