Neurosarcoidosis mimicry of multiple sclerosis: clinical, laboratory, and imaging characteristics.

Objective: To characterize the clinical and laboratory features of neurosarcoidosis (NS), presenting with findings consistent with multiple sclerosis (MS).

Methods: Retrospective chart review of our entire NS database was undertaken. Patients initially diagnosed with MS but who were subsequently diagnosed as having both systemic and neurologic sarcoidosis years later were selected for more detailed review.

Results: Seven patients were identified who were diagnosed with MS (although only 4 of these met McDonald criteria for MS during chart review) and 1 patient with optic neuritis who had a diagnosis of likely MS. These patients maintained the diagnosis of MS for a mean of 107 months (median 50 mo, range 23 to 262 mo) before the diagnosis was changed to NS, concomitant with the discovery of biopsy-proven systemic sarcoidosis in 4 cases. Neurologic manifestations included relapsing-remitting optic neuritis, myelopathy, dystonic spasms, sensory abnormalities, paraparesis, and hemiparesis. Patients appeared to improve or stabilize by treatment with corticosteroids or alternative immunosuppressants. MRIs demonstrated rounded or ovoid periventricular white matter changes typical for MS.

Conclusion: Patients with NS are frequently diagnosed initially with MS because of a considerable overlap of clinical and laboratory features. However, due to the relative rarity of NS, a misdiagnosis of NS as MS occurred only infrequently in our MS clinic.