Reading epilepsy from the dominant temporo-occipital region. Issue 7 (19th July 2009)

• Record Type: Journal Article
• Authors: Gavaret, Martine; Guedj, Eric; Koessler, Laurent; Trébuchon-Da Fonseca, Agnès; Aubert, Sandrine; Mundler, Olivier; Chauvel, Patrick; Bartolomei, Fabrice
• Is Part Of: Journal of neurology, neurosurgery and psychiatry. Volume 81:Issue 7(2010)
• Page Start: 710
• Page End: 715
• Publication Date: 2009-07-19
• Subjects: Reading epilepsy -- reflex epilepsy -- temporal lobe epilepsy -- occipital lobe epilepsy -- epilepsy; Neurology -- Periodicals; Nervous system -- Surgery -- Periodicals; Psychiatry -- Periodicals; 616.8
• DOI: 10.1136/jnnp.2009.175935
• Languages: English
• ISSNs: 0022-3050

Abstract

Abstract : Background: Reading epilepsy is a rare form of epilepsy, classified among idiopathic, age- and localisation-related (partial) epilepsies as a reflex epilepsy syndrome. Seizures usually consist of myoclonic jerks restricted to the jaw. However, distinct ictal features including visual symptoms and paroxysmal a- or dyslexia are described in some patients. The anatomical substrate of ictogenesis in reading epilepsy remains poorly understood. Methods: The authors report here the case of a primary reading epilepsy for which ictal semiology was characterised by visual symptoms and dyslexia, investigated by MRI, interictal high-resolution EEG and PET, ictal video-EEG and SPECT. Brain MRI was normal. Interictal high-resolution EEG was performed with 64 scalp channels, a realistic head model and different algorithms to solve the inverse problem. Results: Interictal source localisations highlighted the left occipito-temporal junction. Interictal PET demonstrated bilateral occipito-temporal hypometabolism with left-sided predominance. Ictal EEG showed a rhythmic discharge in left temporo-parieto-occipital junction channels, with left occipito-temporal predominance. MRI fusion of the coregistered subtraction between ictal and interictal SPECT individualised relative hyperperfusion affecting (a) the left occipito-parietal junction area, (b) the left lateral middle and inferior temporal gyri and (c) the left inferior frontal area. Conclusion: Besides reading-induced myoclonic jerks of the jaw, a second variant of reading epilepsy exists with clearly partial seizures manifested by visual symptoms and a- or dyslexia. These seizures originate from the occipito-temporal region of the dominant hemisphere, corresponding to the posterior part of the neural network that underlies the function of reading.