Evaluation of Regional Cerebral Blood Flow in Alzheimer's Disease Patients with Subclinical Hypothyroidism

<b><i>Background:</i></b> This study examined regional cerebral blood flow (rCBF) in Alzheimer's disease (AD) patients with and without subclinical hypothyroidism (SCH). <b><i>Methods:</i></b> Eleven AD patients with SCH and 141 AD patients without SCH underwent brain perfusion single photon emission computed tomography (SPECT). The SPECT data were analyzed by statistical parametric mapping (SPM8) and FineSRT. <b><i>Results:</i></b> AD patients with SCH showed a significantly decreased rCBF mainly in the temporal lobe and thalamus, whereas those without SCH showed a significantly decreased rCBF in the parietotemporal lobe and cingulate gyrus as well as the frontal lobe. <b><i>Conclusion:</i></b> Our findings suggest that SCH may affect cerebral perfusion in regions associated with the memory function.