This case highlights the fact that anti-IgLON5 disease can exhibit the clinical and radiological changes seen in PSP patients and that neuroimaging markers of CSF dynamics problems (“high-convexity tight sulci” on an MRI and hyperperfusion of the high-convexity on both an ASL-MRI and a perfusion SPECT) may be found in IgLON5. Here, IGLON5 is linked to supranuclear palsy, progressive, 1.