Anti Iglon5 Syndrome: What We Know So Far? A Non-Systematic Review

The objective of this review is to do an overview about the current knowledge of Anti Iglon5 Syndrome, a disease that was first described in 2014. The IgLON proteins are a family of cell adhesion molecules and the presence of antibodies against IgLON5 are crucial for diagnosis of Anti IgLON5 Syndrome. This syndrome has an expanded clinical spectrum that involves prominent sleep disorder, progressive bulbar dysfunction, gait instability with abnormal eye movements reminiscent and cognitive deterioration sometimes associated with chorea. The main neuropathological finding is the neuronal loss with hyperphosphorylated tau (p-Tau) protein accumulation at hypothalamus, brainstem tegmentum, hippocampus, periaqueductal gray matter, medulla oblongata and upper cervical cord. The exact pathogenesis is still unclear and involves a neurodegenerative process and autoimmune response. The early diagnosis is important to avoid unnecessary tests and prevent complications. Important resources for diagnosis are the antibody testing of serum and CSF for IgLON5-IgG. The mortality of anti IgLON5 syndrome is high and new studies published described a good response to immune therapy. However, the response to immune therapy depends of some clinical and analytical characteristic. In addition, future studies are needed to thoroughly study the aspects of pathogenesis and treatment of this important pathological syndrome.