Evaluation of neuronal loss in adult moyamoya disease by 123I-iomazenil SPECT.
BACKGROUND
Central benzodiazepine (BZD) receptor imaging is effective to evaluate neuron density in the pathological brain cortex. This study used BZD receptor imaging to evaluate neuronal damage in adult ischemic moyamoya disease.


METHODS
Single photon emission computed tomography and a novel tracer, 123I-iomazenil, were used to measure BZD receptor density in the brain. Evaluation of early and late images was performed in three asymptomatic, unoperated patients, and six mildly symptomatic, operated patients.


RESULTS
Uptakes in the frontal, parietal, and occipital lobes of symptomatic patients were significantly lower (p<0.05) than those of asymptomatic patients. The late image/ early image count ratios (L/E ratios) of asymptomatic patients were relatively constant (mean, 0.571; range, 0.550-0.581) in all regions of interest. In contrast, the L/E ratios of symptomatic patients were not uniform.


CONCLUSIONS
The neuron density was preserved in adult asymptomatic patients despite harboring moyamoya disease. In contrast, the neuronal density was decreased in symptomatic patients even though their symptoms were mild and they had undergone revascularization.
Department of Neurosurgery, Tohoku University School of Medicine, Sendai, Miyagi, Japan.
S
S
Sato
R
R
Shirane
S
S
Maruoka
T
T
Yoshimoto
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005442:Flumazenil / Q000031:analogs & derivatives*; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D009474:Neurons / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D011963:Receptors, GABA-A / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D007457:Iodine Radioisotopes; D011963:Receptors, GABA-A; D005442:Flumazenil; C063038:iomazenil