Overcoming the Elusiveness of Neurosarcoidosis: Learning from Five Complex Cases.

The involvement of the central nervous system in sarcoidosis can manifest with a variety of neurological symptoms, and most of them can be nonspecific. The diagnosis of neurosarcoidosis (NS) can therefore be very challenging without a tissue biopsy. Both computed tomography (CT) and magnetic resonance imaging (MRI) are important imaging modalities in the diagnosis of NS, and MRI is the modality of choice due to its superior soft-tissue contrast resolution. We present a case series of NS with interesting neuroimaging features, complex neurological presentations, and clinical courses. We identify five cases presenting with clinically isolated neurosarcoidosis (CINS) without any other signs or symptoms of systemic disease which were diagnosed as NS on biopsy. In the first case, we describe a patient with an intramedullary cervical spinal cord lesion. In the second case we describe a patient presenting with inflammatory changes and enhancement in the orbit. The third case demonstrates a lesion with calcification around the region of the foramen of Monro. The fourth case shows multiple ring-enhancing lesions. Lastly, the fifth case exhibits unusual findings with both optic neuritis and a cerebellar nodule. We aim to describe the complicated clinical course with neurological workup, neuro-imaging, and eventual diagnosis and treatment of these challenging cases to highlight the variable presentations of NS. This case series will remind clinicians that NS should always be in the differential diagnosis when a patient presents with nonspecific neurological symptoms with unusual neuroimaging findings.