Claustrum Sign: An Increasingly Recognized Imaging Feature of New-Onset Refractory Status Epilepticus (NORSE)

The claustrum sign, marked by increased MRI signal intensity of the claustrum, is an increasingly recognized imaging finding associated with new-onset refractory status epilepticus (NORSE), and may be associated with a more refractory disease course and worse outcomes. We present a 42-year old male patient who developed NORSE refractory to several treatments including immunotherapy, with MRI demonstrating the claustrum sign early in his disease course. We aim to highlight this sign as an important feature of NORSE, which could alert clinicians to the diagnosis, prompting more extensive workup and aggressive treatment earlier on.