Authors :
Presenting Author: Rei Enatsu, MD, PhD – Sapporo medical university
Tomoaki Tamada, MD, PhD – Sapporo medical university; Takuro Saito, MD, PhD – Sapporo medical university; Ryohei Chiba, MD, PhD – Sapporo medical university; Aya Kanno, MD, PhD – Sapporo medical university; Nobuhiro Mikuni, MD, PhD – Sapporo medical university
Rationale:
The present study investigated the networks of visual functional areas using an electric brain stimulation (EBS) and diffusion tensor imaging (DTI).
Methods:
Thirteen focal epilepsy patients in which visual functional areas were identified by EBS were studied. DTI was applied to depict subcortical fibers from the visual functional areas identified by EBS.
Results:
The electrical stimulation induced three types of visual symptoms: visual illusions (change of vision), visual hallucinations (appearance of a new object), and blurred vision.
Visual illusions were associated with the stimulation of lateral temporo-parieto-occipital areas, and visual hallucinations with the stimulation of lateral/basal temporal areas, occipital lobe and precuneus. Tractography revealed that the superior fronto-occipital fasciculus was associated with visual illusions and the middle longitudinal fasciculus with visual hallucinations, and both symptoms shared several subcortical fibers such as the vertical occipital fasciculus, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, inferior longitudinal fasciculus, optic radiations, and commissural fibers.
Conclusions:
The present results show that the characteristic cortical regions and networks of visual functional areas, and provide a practical guide for electrical cortical stimulation.
Funding: Takeda Science Foundation