Neurosarcoidosis Presented as an Isolated Brain Lesion.

Sarcoidosis is a multisystemic, noncaseating granulomatous disease of unknown etiology. Neurosarcoidosis (NS) is the involvement of the central nervous system (CNS) in sarcoidosis, and it occurs in approximately 5%-10% of cases. NS can present with a variety of clinical features, making diagnosis challenging. A comprehensive diagnostic approach is required to obtain a definitive diagnosis. In this case we present a 13-year-old boy with diabetes mellitus presented with acute right-sided weakness, paresthesia, headaches, and episodes of loss of consciousness, followed by confusion and aggressive behavior. Neurological examination revealed right-sided motor and sensory deficits, as well as abnormal reflexes. Cranial imaging revealed a solitary lesion in the left centrum semi-ovale. Cerebrospinal fluid (CSF) analysis showed lymphoblastic leukocytosis, increased CSF angiotensin-converting enzyme (ACE), and a high IgG index. Extensive laboratory and imaging studies ruled out other potential etiologies. This case presented with a unique set of clinical features, including a mass lesion effect and seizures, which are uncommon in isolated NS. The patient responded well to high-dose corticosteroid therapy, with resolution of his symptoms. Levetiracetam was used to effectively manage his seizures.