Thalamic asymmetry on interictal SPECT in patients with frontal lobe epilepsy.
BACKGROUND
Interictal brain single photon emission computed tomography (SPECT) is useful for the detection of seizure focus. Recent reports indicate a hypoperfusion in the ipsilateral thalamus as a seizure focus on interictal SPECT in temporal lobe epilepsy. In frontal lobe epilepsy (FLE), however, the alteration of perfusion in the thalamus has not been well documented. This study aimed to assess whether perfusion analysis on the thalamus may add useful information for the detection of epileptic foci in patients with FLE.


METHODS
Interictal brain SPECT was performed in 11 patients with FLE. The asymmetry index for the thalamus and frontal area in the SPECT image was calculated in order to compare the laterality of the seizure foci.


RESULTS
Thalamic asymmetry was seen in seven patients (64%), while cortial asymmetry was seen in six patients (55%). The concordance with the lateralization of the seizure foci was 6/7 (86%) in the thalamus, and 4/6 (67%) in the frontal area. Four patients showed only thalamic asymmetry. Concordance with the lateralization of the seizure focus was found in all of them.


CONCLUSIONS
These preliminary results suggest that hypoperfusion in the thalamus may have a complementary role to lateralize the epileptic foci in patients with FLE.
Takano
A
A
Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
Shiga
T
T
Kobayashi
J
J
Adachi
I
I
Nakamura
F
F
Koyama
T
T
Katoh
C
C
Morita
K
K
Tsukamoto
E
E
Tamaki
N
N
D000293:Adolescent; D000328:Adult; D000662:Amphetamines / Q000493:pharmacokinetics; D004569:Electroencephalography; D017034:Epilepsy, Frontal Lobe / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon
D000662:Amphetamines; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; C041336:4-iodoamphetamine