Pseudo pre-excitation ECG changes in a patient with anti-GAD mediated autoimmune limbic encephalitis

Abstract

We report the case of a 30-year-old male patient presenting with complex partial seizures and amnesia and diagnosed with anti-glutamic acid decarboxylase (anti-GAD) mediated autoimmune limbic encephalitis. New onset ECG changes consistent with pre-excitation were co-existent and resolved entirely with immunotherapy. This association has not been previously reported in the literature. Pre-excitation is usually attributable to an accessory cardiac pathway, the presence of which was excluded in the case. Instead, we posit a potential deleterious, reversible effect of anti-GAD antibodies on cardiac membrane stability. Given the risk of sudden cardiac death associated with such ECG profiles, we highlight the need for neurologists to be aware of this potential association and of the possible benefits of specialist cardiological involvement. Further work should be undertaken to elucidate the nature of this association, and clinicians should be mindful of the potentially adverse consequences thereof.