Fibers from the dorsal premotor cortex elicit motor-evoked potential in a cortical dysplasia.
OBJECTIVE
To identify the fibers originating from the dorsal premotor cortex (dorsal PMC) that contribute to motor-evoked potentials (MEP), we have applied integrated functional neuronavigation and awake surgery during removal of an epileptic cortical dysplasia located in the right premotor cortex.


METHODS
Chronic subdural electrodes were employed for functional mapping during a routine invasive evaluation for intractable epilepsy. After the fibers originating from the dorsal PMC were plotted into the tractography-integrated functional neuronavigation, subcortical MEPs and clinical symptoms were examined during resection of the epileptogenic dorsal PMC.


RESULTS
During removal of the epileptogenic area, MEPs were elicited by electrical stimulation of the fibers originating from the dorsal PMC, which were separated from the pyramidal tracts from the precentral gyrus. Resection of the dorsal PMC and its fibers caused a transient dysmetric movement of the left toe without motor weakness.


CONCLUSIONS
Functional corticospinal tract fibers originating from the dorsal PMC can be defined and removed safely under local anesthesia with the aid of integration of functional neuronavigation and subcortical electrical stimulation.
Mikuni
Nobuhiro
N
Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Kyoto, 6068507, Japan. mikunin@kuhp.kyoto-u.ac.jp
Okada
Tsutomu
T
Taki
Junya
J
Matsumoto
Riki
R
Nishida
Namiko
N
Enatsu
Rei
R
Hanakawa
Takashi
T
Ikeda
Akio
A
Miki
Yukio
Y
Urayama
Shin-ichi
S
Fukuyama
Hidenao
H
Hashimoto
Nobuo
N
D000293:Adolescent; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology; D019054:Evoked Potentials, Motor; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology / Q000473:pathology* / Q000503:physiopathology*; D009412:Nerve Fibers / Q000502:physiology*