IgLON5: A case with predominant cerebellar tau deposits and leptomeningeal inflammation

In 2014, a novel tauopathy characterized by REM sleep behavior disorder (RBD), sleep apnea, and stridor was first reported.1 Association with serum and CSF antibodies against IgLON5, a neuronal cell adhesion molecule of unknown function, was found in all patients.1 Neuropathologic examinations revealed neuronal accumulation of hyperphosphorylated 3-repeat (3R) and 4-repeat (4R) tau deposits in the hypothalamus and tegmental brainstem nuclei as the most relevant finding in the absence of inflammatory changes.2