Localizing value of epileptic visual auras

• Published in: Brain (London, England : 1878) Vol. 123; no. 2; pp. 244 - 253
• Main Authors: Bien, Christian G., Benninger, Felix O., Urbach, Horst, Schramm, Johannes, Kurthen, Martin, Elger, Christian E.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.02.2000; Oxford Publishing Limited (England)
• Subjects: Adolescent; Adult; Biological and medical sciences; Child, Preschool; epilepsy; Epilepsy - physiopathology; Female; focus localization; Hallucinations - physiopathology; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Male; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Occipital Lobe - pathology; occipital lobe epilepsy; Temporal Lobe - pathology; temporal lobe epilepsy; visual auras; Visual Fields; Visual Perception; Human; Nervous system diseases; Hallucination; Vision disorder; Epileptic focus; Complex partial epilepsy; Differential diagnostic; Cerebral disorder; Occipital lobe epilepsy; Refractory; Symptomatology; Eye disease; Central nervous system disease; Temporal lobe epilepsy; Aura; Localization
• ISSN: 0006-8950; 1460-2156
• DOI: 10.1093/brain/123.2.244

It is difficult to differentiate between seizures of occipital or temporal lobe origin in patients with focal epileptic seizures associated with visual aura. These are often suspected to originate from the visual cortex, which causes reluctance to propose resection as treatment for the affected patient. To determine the value of localizing different types of visual auras, we report on 20 patients experiencing visual aura from a series of 878 surgically treated patients suffering from intractable focal seizures. In all of these patients, a morphological abnormality was identified on MRI (n = 18) or cranial CT (n = 2). These abnormalities were shown to represent the morphological correlate of the epileptogenic zone in each case, as demonstrated by intracranial ictal EEG recordings and/or seizure freedom after focal resective surgery. Elementary hallucinations, illusions and visual loss were reported not only by all patients with occipital lobe epilepsy, but also by patients with occipitotemporal and anteromedial temporal seizure onset. Complex hallucinations never occurred in occipital lobe seizures but were present in the two other groups. The same correlation was found for concentric changes of visual field (tunnel vision), a newly described ictal phenomenon. We conclude that elementary hallucinations, illusions and visual loss, although typical for occipital lobe epilepsy, can also occur in anteromedial temporal or occipitotemporal seizures and are therefore not a discordant feature in presurgical evaluation of patients with suspected temporal lobe epilepsy. Complex hallucinations and tunnel vision, however, should be considered concordant only with the assumption of an anteromedial temporal or occipitotemporal seizure onset.