[Assessment of cerebral benzodiazepine receptor distribution in anxiety disorders by 123I-iomazenil-SPECT: comparison to cerebral perfusion scintigraphy by 123I-IMP].

123I-Iomazenil (123I-IMZ) and 123I-IMP imaging were performed in 5 patients with anxiety disorder (PAD) and 6 normal volunteers (NV). On 123I-IMZ delayed imaging, the 2 PAD showed abnormally decreased findings. In anxiety disorder, decreased accumulation on 123I-IMZ delayed images was seen in left hippocampus and parahippocampal gyrus in one patient, in right frontal and temporal lobe and left occipital pole in the other. Compared with NV, PAD had lower 123I-IMZ uptake on delayed image in right upper and left lower frontal cortices, indicating the involvement of the benzodiazepine receptor complex in anxiety disorder. Compared with grading for anxiety disorder with Hamilton anxiety scale (HAS) and delayed to early count ratios of 123I-IMZ, negative correlation (R < -0.7) was recognized hippocampus and parahippocampal gyrus, frontal and occipital cortices. Compared between HAS and the count ratio to the cerebellum on 123I-IMP image, positive correlation (R > 0.7) was recognized in the hippocampus, the parahippocampal gyrus, the lower outer temporal cortex and the lower frontal cortex.