Role of fluorodeoxyglucose positron emission tomography in the diagnosis of neurosarcoidosis.

A 45-year-old man developed seizures and myelopathy. MRI showed bitemporal and cervical spinal cord hyperintense lesions on T2-weighted and FLAIR images that contrast-enhanced. Initial evaluation for sarcoidosis was negative, including serum angiotensin converting enzyme (ACE) and chest X-ray. Whole body fluorodeoxyglucose positron emission tomography (FDG-PET) revealed multiple hypermetabolic hilar and mediastinal foci and spinal cord hypermetabolism at the site of MRI abnormality. Temporal lobe MRI lesions were hypometabolic. Mediastinal lymph node biopsy was consistent with sarcoidosis. The brain, spinal cord, and chest metabolic abnormalities together with the clinical presentation were interpreted as being most consistent with sarcoidosis. FDG-PET helped target the site of biopsy that subsequently confirmed the diagnosis histologically. In patients with perplexing neurologic presentations, whole body FDG-PET can help secure a timely and minimally invasive diagnosis of neurosarcoidosis.