BACKGROUND: The Anti-IgLON5 disease was first described as an abnormal neurological condition explained by a dual etiology hypothesis of neurodegeneration and autoimmunity.
CASE: A 64-year-old man with a 2-year history of aplastic anemia presented with neurological symptoms and signs including symmetrical parkinsonism, fluctuation in consciousness, supranuclear gaze palsy, mild fasciculation, and muscular atrophy. Three months earlier, he was referred to a sleep clinic, and polysomnography (PSG) revealed a sleep efficiency of 63.6%, increased sleep stages 1 and 2, and the absence of N3 stage or REM sleep. Brain MRI showed extensive cortical atrophy with significant Virchow-Robin spaces. CSF analysis was unremarkable, except a positive test result was achieved later for the IgLON5 antibody. Immunotherapy was initiated with high-dose methylprednisolone and intravenous immunoglobulin followed by treatment with rituximab. A mild to moderate response to treatment was observed in this case.
REVIEW OF THE LITERTURE: In this study we reviewed 29 published case reports about anti-Iglon 5 and examined all of the clinical manifestations that patients experienced with detail. None of the cases showed aplastic anemia, which was the main finding in our case. All of the patients experienced sleep disturbances in the course of their disease, but other symptoms were heterogeneous.
CONCLUSION: Correlation of cognitive symptoms in the absence of sleep disturbances at the beginning of the course of the anti-IgLON5 disease may lead to a late diagnosis and a worse prognosis. This study also had a unique impression on available documents, which could cause further changes to the notion of an association between other autoimmune disorders, such as anemia in this case and anti-IgLON5 disease.