Effects Of Thyroid Dysfunction On Spatial And Object Memory In The Adult Patients

Objective To explore the effects of thyroid dysfunction on spatial and object memory in the adult patients.Methods The patients with thyroid dysfunction were recruited from the Department of Endocrinology, the First Hospital of Anhui Medical University, from March 2013 to November 2013. According to thyroid hormone levels, the patients were divided into hyperthyroidism group(42 cases) and hypothyroidism group(16 cases). Furthermore, in each group the patients were divided into antibody-positive and antibody-negative subgroups according to whether they had thyroid-related antibodies. After the patients’ background information was collected, the Nine-Box Maze test was used to assess their spatial and object memories. Normal individuals were enrolled as the controls(27 cases). The patients were treated with proper medications, regularly followed-up, and re-tested after six months. Statistical analysis was performed by using SPSS 17.0, and t test, ANOVA, rank test orχ2 test were used to reveal any significant difference between groups.Results Compared to the controls, the hyperthyroidism patients had higher errors in the spatial reference(z = 2.407,P = 0.016)and object(z = 7.553,P < 0.001)memories, and so did the hypothyroidism patients in the object memory(z = 6.221,P < 0.001). The antibody-positive patients with hyperthyroidism showed more errors in the spatial reference(z = 3.695,P < 0.001), spatial working(z = 2.693,P = 0.007) and object(z = 6.415,P < 0.001)memories than the controls, and the antibody-positive patients with hypothyroidism had similar findings in the spatial working(z = 2.574,P = 0.010) and object(z = 5.655,P < 0.001)memories. In the antibody negative subgroups, the hyperthyroidism and hypothyroidism patients only displayed more errors in the object memory than the controls(z = 6.699、5.422,Ps < 0.001). 6 months after drugs treatment the patients had not significant decrement in the errors of spatial reference and object recognition memories.Conclusion The patients with thyroid dysfunction, especially for the antibody-positive individuals, had a certain degree of memory impairment, and autoimmune factor may be a cause involved in their cognitive damage. After the drug treatment, impaired cognitive function had no significant improvement.