Visual cortex hyperexcitability in idiopathic generalized epilepsies with photosensitivity: A TMS pilot study

BACKGROUND: The current understanding of the mechanisms underlying photosensitivity is still limited, although most studies point to a hyperexcitability of the visual cortex. METHODS: Using transcranial magnetic stimulation, we determined the resting motor threshold (rMT) and the phosphene threshold (PT) in 33 patients with IGEs (8 with photosensitivity) compared with 12 healthy controls. RESULTS: Eleven controls (92%) reported phosphenes compared with fifteen (46%) patients with idiopathic generalized epilepsy (p=0.015). Phosphenes were reported more frequently among patients with epilepsy with photosensitivity (87.5%) than in patients with active epilepsy without photosensitivity (30.8%) (p=0.038) and patients with epilepsy in remission without photosensitivity (33.3%) (p=0.054); no differences were found between patients with epilepsy with photosensitivity and controls (p=0.648). Resting motor threshold and phosphene threshold were significantly higher among patients with epilepsy (active epilepsy or epilepsy in remission without photosensitivity) compared to healthy controls (p