Preoperative amygdala fMRI in temporal lobe epilepsy.
OBJECTIVE
Anterior temporal lobe resections (ATLR) benefit 70% of patients with refractory mesial temporal lobe epilepsy (TLE), but may be complicated by emotional disturbances. We used functional magnetic resonance imaging (fMRI) to investigate the role of the amygdala in processing emotions in TLE and whether this may be a potential preoperative predictive marker for emotional disturbances following surgery.


METHODS
We studied 54 patients with refractory mesial TLE due to hippocampal sclerosis (28 right, 26 left) and 21 healthy controls using a memory encoding fMRI paradigm, which included viewing fearful and neutral faces. Twenty-one TLE patients (10 left, 11 right) subsequently underwent ATLR. Anxiety and depression were assessed preoperatively and 4 months postoperatively using the Hospital Anxiety and Depression Scale.


RESULTS
On viewing fearful faces, healthy controls demonstrated left lateralized, while right TLE patients showed bilateral amygdala activation. Left TLE patients had significantly reduced activation in left and right amygdalae compared to controls and right TLE patients. In right TLE patients, left and right amygdala activation was significantly related to preoperative anxiety and depression levels, and preoperative right amygdala activation correlated significantly with postoperative change of anxiety and depression scores, characterized by greater increases in anxiety and depression in patients with greater preoperative activation. No such correlations were seen for left TLE patients.


CONCLUSIONS
The fearful face fMRI paradigm is a reliable method for visualizing amygdala activation in controls and patients with mesial TLE. Activation of the right amygdala preoperatively was predictive of emotional disturbances following right ATLR.
Bonelli
Silvia B
SB
Dept of Clinical and Experimental Epilepsy, NSE MRI Unit, Institute of Neurology UCL, Queen Square, London, United Kingdom.
Powell
Robert
R
Yogarajah
Mahinda
M
Thompson
Pamela J
PJ
Symms
Mark R
MR
Koepp
Matthias J
MJ
Duncan
John S
JS
D000293:Adolescent; D000328:Adult; D000342:Affective Symptoms / Q000503:physiopathology / Q000517:prevention & control; D000679:Amygdala / Q000503:physiopathology*; D038481:Anterior Temporal Lobectomy; D001008:Anxiety Disorders / Q000503:physiopathology / Q000517:prevention & control; D001143:Arousal / Q000502:physiology; D003866:Depressive Disorder / Q000503:physiopathology / Q000517:prevention & control; D004292:Dominance, Cerebral / Q000502:physiology; D004644:Emotions / Q000502:physiology*; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology* / Q000601:surgery; D005149:Facial Expression; D005239:Fear / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology; D011183:Postoperative Complications / Q000503:physiopathology / Q000517:prevention & control; D012307:Risk Factors; D012598:Sclerosis; D055815:Young Adult