The change of cerebral blood flow in depression of hypothyroidism in induced by post-thyroidectomy

点击翻译按钮获取中文摘要

The study investigated alterations in regional cerebral blood flow (rCBF) distribution in patients with transient hypothyroidism, post-thyroidectomy, using 99mTc-HMPAO SPECT and statistical parametric mapping (SPM96). The effect of thyroxine treatment on rCBF change was also studied. The measurements were done both before 131I therapy and after thyroid hormone (thyroxin) therapy. We used the adjusted rCBF images in relative flow redistribution to compare these data with normal control groups using SPM96. We also analyzed the association between rCBF and the severity of the patients' depression. The effect of thyroid hormone replacement was investigated by a group comparison test between the hypothyroidic state and the euthyroidic state. For statistical analysis, both a group comparison test and the Jack-Knife test were done. The group comparison study showed that in the hypothyroidic state, there was a significant decrease in adjusted rCBF in the bilateral parietal lobe, including the … More precuneus and in part of the bilateral occipital lobe, including the cuneus. The areas of significantly low perfusion extended to the bilateral prefrontal cortex in accordance with the progression of the severity of depression. On the Jack-Knife test, 66.7% showed rCBF reduction. The Jack-Knife test given after thyroxine administration showed improvement in 56.3% patients. 43.7% with abnormal rCBF at the baseline study did not show any change at the follow-up study. In group comparison studies, all those areas with decreased rCBF did not show significant changes after thyroxin replacement treatment. The current study demonstrated a significant rCBF decrease in transient hypothyroidic condition after thyroidectomy and before 131I therapy. Abnormalities in this rCBF-reduced area, including the parietal lobe, part of the occipital lobe, and progressing to the prefrontal cortex, may be important in understanding cognitive dysfunction and depression in patients with transient hypothyroidism. Based on the insignificant change in rCBF after thyroxin therapy, the reduction of rCBF under the induced hypothyroidic condition was thought to be prolonged or irreversible during short-term follow up. Less