Positive and negative network correlations in temporal lobe epilepsy.
Temporal lobe seizures are accompanied by complex behavioral phenomena including loss of consciousness, dystonic movements and neuroendocrine changes. These phenomena may arise from extended neural networks beyond the temporal lobe. To investigate this, we imaged cerebral blood flow (CBF) changes during human temporal lobe seizures with single photon emission computed tomography (SPECT) while performing continuous video/EEG monitoring. We found that temporal lobe seizures associated with loss of consciousness produced CBF increases in the temporal lobe, followed by increases in bilateral midline subcortical structures. These changes were accompanied by marked bilateral CBF decreases in the frontal and parietal association cortex. In contrast, temporal lobe seizures in which consciousness was spared were not accompanied by these widespread CBF changes. The CBF decreases in frontal and parietal association cortex were strongly correlated with increases in midline structures such as the mediodorsal thalamus. These results suggest that impaired consciousness in temporal lobe seizures may result from focal abnormal activity in temporal and subcortical networks linked to widespread impaired function of the association cortex.
Blumenfeld
Hal
H
Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA. hal.blumenfeld@yale.edu
McNally
Kelly A
KA
Vanderhill
Susan D
SD
Paige
A LeBron
AL
Chung
Richard
R
Davis
Kathryn
K
Norden
Andrew D
AD
Stokking
Rik
R
Studholme
Colin
C
Novotny
Edward J
EJ
Zubal
I George
IG
Spencer
Susan S
SS
D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000098:blood supply* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D004569:Electroencephalography / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000503:physiopathology*; D005246:Feedback; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D012640:Seizures / Q000150:complications / Q000503:physiopathology*; D013223:Statistics as Topic; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods