Short communication Role of fluorodeoxyglucose positron emission tomography in the diagnosis of neurosarcoidosis Neeraj Dubey a,b , Robert S. Miletich a,b,c , Mohammad Wasay d , Laszlo L. Mechtler a,b,c , Rohit Bakshi a,b,c,e, * a Dent Neurologic Institute, Buffalo, NY, USA b Imaging Services, Kaleida Health-Millard Fillmore Hospital, Buffalo, NY, USA c Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA d Department of Neurology, The Aga Khan University, Karachi, Pakistan e Buffalo Neuroimaging Analysis Center, The Jacobs Neurological Institute, Buffalo, NY, USA Received 22 October 1999; received in revised form 28 June 2002; accepted 3 July 2002 Abstract 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. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Sarcoidosis; Neurosarcoidosis; Brain; Inflammation; Positron emission tomography; Magnetic resonance imaging 1. Introduction Sarcoidosis is an idiopathic systemic granulomatous disease. Central nervous system involvement is reported in approximately 5% cases and usually occurs early in the disease [1]. Neurosarcoidosis includes a wide variety of clinical presentations such as cranial neuropathy, aseptic meningitis, neuroendocrine dysfunction and hydrocephalus [1,2]. Hilar adenopathy on chest X-ray, abnormal gallium scan, and elevated serum and cerebrospinal fluid (CSF) angiotensin converting enzyme (ACE) levels in the presence of neurologic involvement are suggestive of neurosarcoido- sis. However, neurosarcoidosis may occur with a normal chest X-ray and normal ACE levels, posing a diagnostic challenge. Fluorodeoxyglucose positron emission tomogra- phy (FDG-PET) may be useful in the diagnosis of systemic sarcoidosis [3–9]. We report a young man with bilateral temporal and cervical cord lesions with a normal chest X- ray and normal serum ACE. Whole body FDG-PET was useful in making the diagnosis of sarcoidosis leading to biopsy confirmation. To our knowledge, this is the first reported case of neurosarcoidosis demonstrating the diag- nostic utility of FDG-PET. 2. Case report A 45-year-old man noted a strange chemical smell several times a day and numbness and tightness around his chest during the previous 4 weeks. General physical examination was unremarkable. Neurologic examination showed a T-1 sensory level. Interictal EEG revealed left temporal spike and wave discharges. Carbamazepine was prescribed for probable olfactory seizures. Erythrocyte sedimentation rate, complete blood count, chemistry profile 0022-510X/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII:S0022-510X(02)00225-3 * Corresponding author. Buffalo Neuroimaging Analysis Center, The Jacobs Neurological Institute, 100 High St. Buffalo, NY 14203, USA. Tel.: +1-716-859-7592; fax: +1-716-859-7573. E-mail address: rbakshi@buffalo.edu (R. Bakshi). www.elsevier.com/locate/jns Journal of the Neurological Sciences 205 (2002) 77 – 81