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Abstract #18388 Published in IGR 3-3
Differential diagnosis of visual aura in migraine and epilepsy
Schulze-Bonhage AKlinische Monatsblätter für Augenheilkunde 2001; 218: 595-602
Visual phenomena such as lightning, disturbed contours of objects, or scotoma, can be due to ophthalmological diseases, but can also occur as symptoms generated by the central nervous system ('aura') in migraine or epilepsy. A subsequent hemicrania is considered a hallmark of migraine, but in many cases does not enable distinction from postictal headaches in patients with focal epilepsy. However, detailed analysis of the aura does provide sufficient information for classifying the disorder as an aura in migraine or as a simple partial epileptic seizure in most cases. The higher degree of differentiation of visual phenomena including color, movement, and complex visual phenomena, is characteristic of the activation of neuronal circuits during an epileptic aura. The higher speed of transsynaptic propagation of epileptic discharges and postictal inactivation causes a more rapid time course of the epileptic aura compared to a migraine aura resulting from depolarization spreading by diffusion. Clinically, the diagnosis of epilepsy is supported by additional positive motor phenomena or by transition into a complex partial seizure, e.g., when epileptic activity spreads into a temporal lobe. However, secondarily generalized seizures may also occur in patients with migraine. Interictal and ictal EEG recordings can be important in proving epileptic origin, but their sensitivity is low if ictal discharges remain limited to a small area of the brain. In rare cases, measurements of ictal cerebral perfusion can contribute to the differential diagnosis. LA: German
Dr A. Schulze-Bonhage, Sektion Prächirurgische Epilepsiediagnostik am Neurozentrum der Universität Freiburg, Breisacher Strasse 64, 79102 Freiburg, Germany. schulzeb@nz.ukl.uni-freiburg.de