Changes in glutamate concentration, glucose metabolism, and cerebral blood flow during focal brain cooling of the epileptogenic cortex in humans.
OBJECTIVE
Recently, focal brain cooling (FBC) was proposed as a method for treating refractory epilepsy. However, the precise influence of cooling on the molecular basis of epilepsy has not been elucidated. Thus the aim of this study was to assess the effect of FBC on glutamate (Glu) concentration, cerebral blood flow (CBF), and glucose metabolism in patients with intractable epilepsy.


METHODS
Nine patients underwent FBC at 15°C for 30 min prior to cortical resection (n = 6) or hippocampectomy (n = 3). Measurement of metabolites and CBF, as well as electrocorticography (ECoG), was performed.


RESULTS
Epileptic discharge (ED), as observed by ECoG, disappeared in the cooling period and reappeared in the rewarming period. Glu concentrations were high during the precooling period and were reduced to 51.2% during the cooling period (p = 0.025). Glycerol levels showed a similar decrease (p = 0.028). Lactate concentration was high during the precooling period and was reduced during the cooling period (21.3% decrease; p = 0.005). Glucose and pyruvate levels were maintained throughout the procedure. Changes in CBF were parallel to those observed by ECoG.


CONCLUSIONS
FBC reduced EDs and concentrations of Glu and glycerol. This demonstrates the neuroprotective effect of FBC. Our findings confirm that FBC is a reasonable and optimal treatment option for patients with intractable epilepsy.
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Sadahiro
S
Nomura
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Masami
M
Fujii
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Takao
T
Inoue
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Yeting
Y
He
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Yuichi
Y
Maruta
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Hiroyasu
H
Koizumi
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Eiichi
E
Suehiro
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Hirochika
H
Imoto
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Hideyuki
H
Ishihara
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Fumiaki
F
Oka
Department of Anesthesiology, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Mishiya
M
Matsumoto
Department of Organ Anatomy, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Yuji
Y
Owada
Fuzzy Logic Systems Institute, Kitakyushu, Fukuoka, Japan.
Takeshi
T
Yamakawa
Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan.
Michiyasu
M
Suzuki
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001921:Brain / Q000098:blood supply*; D002540:Cerebral Cortex / Q000503:physiopathology / Q000601:surgery*; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000503:physiopathology / Q000601:surgery*; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism; D006624:Hippocampus / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods*; D019289:Pyruvic Acid / Q000378:metabolism; D012039:Regional Blood Flow / Q000502:physiology; D017694:Rewarming; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
D001786:Blood Glucose; D019344:Lactic Acid; D018698:Glutamic Acid; D019289:Pyruvic Acid; D005990:Glycerol
Cerebral blood flow; Epilepsy; Glutamate; Hypothermia; Lactate