Interictal 99mTc-HMPAO SPECT in temporal lobe epilepsy: relation to clinical variables.
OBJECTIVE
Factors affecting blood flow observed by interictal single-photon emission computed tomography (SPECT) images in temporal lobe epilepsy (TLE) have not been systematically studied or consistently demonstrated. We evaluated interictal SPECT results with respect to many clinical variables in a large population of TLE patients, all of whom underwent temporal lobectomy.


METHODS
Interictal 99mTc-HMPAO SPECT scans from 61 TLE patients were obtained before an anterior temporal lobectomy. SPECT was analyzed using a region of interest analysis (ROI) in the cerebellum, anterior temporal lobe, lateral temporal lobe, mesial temporal lobe, whole temporal lobe, and inferior frontal lobe. Asymmetry indices (AIs) were calculated. Correlative analysis of AIs and clinical variables was performed.


RESULTS
The AIs from TLE patients differed significantly from those of controls in the anterior temporal (p < 0.01), lateral temporal (p < 0.001), and whole temporal (p < 0.01) regions. No consistent overall correlation between the AIs and clinical variables existed. In right TLE (RTLE) only, AIs in the lateral and whole temporal lobe were positively correlated with age of onset (r = 0.470, p < 0.05; r = 0.548, p < 0.01, respectively). Similarly, in RTLE only, duration of epilepsy was negatively correlated with the anterior (r = -0.395, p < 0.05) and mesial (r = -0.45, p < 0.05) temporal lobe AI. No correlations were found between clinical variables and AIs in left TLE (LTLE) patients.


CONCLUSIONS
Significant correlation of age at onset and duration of epilepsy with AIs in RTLE but not LTLE suggests physiologic processes may be determined in part by laterality of TLE. Clinical applications are problematic.
Avery
R A
RA
Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520-8018, USA.
Zubal
I G
IG
Studholme
C
C
Slawski
J
J
Corsi
M
M
Spencer
D D
DD
Spencer
S S
SS
D000328:Adult; D017668:Age of Onset; D002531:Cerebellum / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D005625:Frontal Lobe / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D019690:Technetium Tc 99m Exametazime; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000601:surgery; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome
D019690:Technetium Tc 99m Exametazime