The Neuroimaging Spectrum of Neurosarcoidosis

ABSTRACT Among its many forms, involvement of the nervous system in sarcoidosis ranks as one of the most severe and potentially disabling manifestations of the disease, and timely recognition and accurate diagnosis are critical for its optimal treatment. Neurosarcoidosis may assume almost any clinicoradiographic phenotype, and as such, neuroimaging is central to its diagnosis and long‐term management. In this review of neuroimaging findings in neurosarcoidosis, overarching radiographic themes are presented, which are followed by detailed explanations of its varied phenotypes alongside neuroimaging figures to illustrate key abnormalities seen in the disorder. The role of structures exposed to cerebrospinal fluid in the cranial compartment (meninges, cranial nerves, ventricles) is explored first, followed by brain parenchymal involvement (standard and tumefactive enhancing lesions, nonenhancing white matter disease), and then sellar and parasellar disease (hypothalamus, infundibulum, pituitary gland, cavernous sinus). Its cerebrovascular manifestations (ischemic stroke, intracranial hemorrhage, medullary vein engorgement, radial perivascular enhancement) and spinal manifestations (spinal cord, spinal nerve roots, and cauda equina) are then discussed. The review concludes with a discussion of the differential diagnosis stratified by neuroanatomical location.