Intracranial Tuberculoma Presenting as an Isolated Oculomotor Nerve Paresis

BackgroundThe differential diagnosis of isolated oculomotor nerve paresis ranges from benign to potentially lethal pathologies. Intracranial tuberculosis (TB), as in the case of this patient, carries a high morbidity and mortality. Early diagnosis is crucial to improve patient outcomes.Case ReportWe present the case of a 46-year-old man with a chief complaint of 5 days of diplopia. His examination was remarkable for right inferolateral exotropia and weakness of the right medial rectus. Due to the neurologic findings, we obtained a computed tomography brain scan, which revealed a ring-enhancing lesion within the central midbrain with vasogenic edema causing mass effect on the cerebral aqueduct. Further evaluation revealed tuberculosis (TB) as the underlying etiology. He was placed on steroids and a four-drug anti-TB regimen with resultant improvement of his symptoms.Why Should An Emergency Physician Be Aware of This?Intracranial tuberculoma can present with an isolated oculomotor nerve paresis in the absence of pulmonary or systemic symptoms. This case emphasizes the importance of maintaining a broad differential when investigating isolated oculomotor nerve paresis.