Bottom line: Unless there are additional neurologic signs or symptoms, neurologic testing for syncope is rarely helpful.
Linzer, M, et al. “Diagnosing syncope. Part 1: Value of history, physical examination, and electrocardiography. Clinical Efficacy Assessment Project of the American College of Physicians.” Annals of Internal Medicine 126.12 (1997):989-96.
A review of the literature on diagnostic testing for syncope resulted in this guideline and its conclusion that “neurologic testing is rarely helpful unless additional neurologic signs or symptoms are present (diagnostic yield of electroencephalography, computed tomography, and Doppler ultrasonography, 2% to 6%).”