Schraml Frank V, Beason-Held Lori L, Fletcher Douglas W, Brown Brian P
Department of Radiology, National Naval Medical Center, Bethesda, Maryland, USA.
J Cereb Blood Flow Metab. 2006 Mar;26(3):321-9. doi: 10.1038/sj.jcbfm.9600191.
Thyroid dysfunction is a well-known contributor to psychiatric morbidity. To investigate the mechanism(s) by which thyroid hormone availability affects cerebral activity, a group of thyroidectomized individuals were studied at two points in time: when markedly hypothyroid in preparation for a thyroid cancer metastatic survey and when clinically and/or biochemically euthyroid. The analysis consisted of single photon emission computed tomography (SPECT) using a lipophilic radiopharmaceutical, technetium-99m (Tc-99m) ethyl cysteinate dimer (ECD), and measurement of mood, anxiety, and psychomotor function, at both points in time. Both increases and decreases in regional cerebral radiotracer activity were found in the hypothyroid condition relative to the euthyroid condition, and the neuropsychological assessment demonstrated significantly greater depression, anxiety, and psychomotor slowing during the hypothyroid state. Increased radiotracer activity was seen in frontal and temporal regions, posterior cingulate gyrus, thalamus, and putamen. Decreased activity was seen in the occipital cortex, and the pre- and postcentral gyri. This distribution pattern is partially consistent with findings in persons with depression and anxiety unrelated to thyroid disease, supporting the link between the symptoms observed in our subjects and their marked hypothyroidism. Finally, these results support the need to consider the effect of the thyroid state on cellular mechanisms of uptake and retention of cerebral blood flow radiopharmaceuticals when studying 'noneuthyroid' individuals.
甲状腺功能障碍是导致精神疾病的一个众所周知的因素。为了研究甲状腺激素可利用性影响大脑活动的机制，一组甲状腺切除的个体在两个时间点接受了研究：在为甲状腺癌转移调查做准备时明显甲状腺功能减退，以及在临床和/或生化指标处于甲状腺功能正常时。分析包括使用亲脂性放射性药物锝-99m（Tc-99m）乙半胱氨酸二聚体（ECD）进行单光子发射计算机断层扫描（SPECT），以及在两个时间点测量情绪、焦虑和精神运动功能。与甲状腺功能正常状态相比，甲状腺功能减退状态下发现局部脑放射性示踪剂活性既有增加也有减少，神经心理学评估显示在甲状腺功能减退状态下抑郁、焦虑和精神运动迟缓明显更严重。在额叶和颞叶区域、后扣带回、丘脑和壳核中观察到放射性示踪剂活性增加。在枕叶皮质以及中央前回和中央后回中观察到活性降低。这种分布模式与与甲状腺疾病无关的抑郁症和焦虑症患者的研究结果部分一致，支持了我们研究对象中观察到的症状与其明显的甲状腺功能减退之间的联系。最后，这些结果支持在研究“非甲状腺功能正常”个体时需要考虑甲状腺状态对脑血流放射性药物摄取和滞留细胞机制的影响。
