Combined electroencephalography and measurements of transcranial blood flow velocity during orthostatic testing--a new approach to assess syncope of unknown origin?

Differential diagnosis of syncope and seizures frequently imposes a major problem, particularly if interictal examinations are normal. We performed orthostatic testing combined with surface electroencephalography (EEG) and non-invasive measurements of cerebral blood flow velocity. Ten healthy controls, ten patients with confirmed diagnosis of epilepsy and 25 patients with history of syncope of unknown origin were examined. The following parameters were evaluated continuously and simultaneously during orthostatic challenge: computerized EEG with synchronous video-monitoring, transcranial Doppler sonography (TCD), heart rate and blood pressure. Isolated cerebrovascular dysregulation (i.e. a drop in cerebral perfusion despite the absence of a significant drop in peripheral blood pressure) occurred in 2/10 controls, 3/10 patients with epilepsy and 11/25 patients with syncope of unknown origin. The combined EEG and TCD measurements represent a new approach to the work-up of patients with otherwise unexplained syncope, helping us to understand the interdependence of neuronal activity and peripheral/cerebrovascular autoregulation under postural stress.

Ultrasonic angiographic and pathologic correlation of noncystic-appearing renal masses.

The ultrasonic echo pattern of renal masses is retrospectively correlated with the angiographic vascular pattern in 36 cases where a noncystic-appearing mass was identified by either study. Pathologic or cytologic correlation was available in 31 of these masses. In carcinomas the echogenicity was usually found to correlate well with the degree of neovascularity.