Introduction:

New clinical entities related to the discovery of autoantibodies either against intracellular antigens or against cell membrane surface receptors or synapses are being identified with increasing frequency. In the latter group, patients with apnea have been described in recent years, REM and NON-REM sleep behavior disorder, respiratory failure and presence in serum and CSF of antibodies against the LON5 antigen. These antibodies appear to alter the interaction with the cytoskeletal system of the neuron and induce accumulation of TAU, conditioning a wide clinical expression.

Clinical case:

76-year-old male patient with eight years evolution of symptoms before diagnosis. He had a mixture of respiratory symptoms, parasomnias, ataxia, movement disorder, autonomic symptoms, cognitive and mood disorder, and associated a chronic demyelinating polyneuropathy. The diagnosis was confirmed by detection of antibodies against IGLON5 in cerebrospinal fluid.

Conclusion:

Anti-IGLON5 antibody encephalitis is a unique entity that challenges what we know about autoimmunity and neurodegeneration, leading to a diagnostic challenge due to the wide expression of symptoms and the possibility of improvement with early treatment.