OBJECTIVE: We hypothesized that prominent pulvinar hypointensity in brain MRI represents the disease process due to iron accumulation in Alzheimer disease (AD). We aimed to determine whether or not the pulvinar signal intensity (SI) on the fluid-attenuated inversion recovery (FLAIR) sequences at 3.0T MRI differs between AD patients and normal subjects, and also whether the pulvinar SI is correlated with the T2* map, an imaging marker for tissue iron, and a cognitive scale. MATERIALS AND METHODS: Twenty one consecutive patients with AD and 21 age-matched control subjects were prospectively included in this study. The pulvinar SI was assessed on the FLAIR image. We measured the relative SI ratio of the pulvinar to the corpus callosum. The T2* values were calculated from the T2* relaxometry map. The differences between the two groups were analyzed, by using a Student t test. The correlation between the measurements was assessed by the Pearson's correlation test. RESULTS: As compared to the normal white matter, the FLAIR signal intensity of the pulvinar nucleus was significantly more hypointense in the AD patients than in the control subjects (p < 0.01). The pulvinar T2* was shorter in the AD patients than in the control subjects (51.5 +/- 4.95 ms vs. 56.5 +/- 5.49 ms, respectively, p = 0.003). The pulvinar SI ratio was strongly correlated with the pulvinar T2* (r = 0.745, p < 0.001). When controlling for age, only the pulvinar-to-CC SI ratio was positively correlated with that of the Mini-Mental State Examination (MMSE) score (r = 0.303, p < 0.050). Conversely, the pulvinar T2* was not correlated with the MMSE score (r = 0.277, p = 0.080). CONCLUSION: The FLAIR hypointensity of the pulvinar nucleus represents an abnormal iron accumulation in AD and may be used as an adjunctive finding for evaluating AD.
Aged ; Alzheimer Disease/*metabolism/*pathology ; Female ; Humans ; Iron/*metabolism ; *Magnetic Resonance Imaging ; Male ; Pulvinar/metabolism/*pathology

BACKGROUND: To investigate postoperative changes in the cerebral glucose metabolism of patients with mesial temporal lobe epilepsy (MTLE), statistical parametric mapping (SPM) analysis was performed on pre- and post-operative 18F-fluorodeoxy glucose positron emission tomographic (FDG-PET) images. METHODS: We included 28 patients with MTLE who had under-gone surgery and had been seizure free postoperatively (16 had left MTLE and 12 right MTLE). All patients showed hippocampal sclerosis by pathology or brain MRI. FDG-PET images of the 12 right TLE patients were reversed to lateralize the epileptogenic zone to the left side in all patients. RESULTS: Application of the paired t-test in SPM to pre- and postoperative FDG-PETs showed that the postoperative glucose metabolism decreased in the caudate nucleus, pulvinar of thalamus, fusiform gyrus, lingual gyrus, and in the posterior region of the insular cortex in the hemisphere ipsilateral to resection, whereas postoperative glucose metabolism increased in the anterior region of the insular cortex, temporal stem white matter, midbrain, inferior precentral gyrus, anterior cingulate gyrus, and supramarginal gyrus in the hemisphere ipsilateral to resection. No significant postsurgical changes of cerebral glucose metabolism occurred in the contralateral hemisphere. Subtraction between pre- and postoperative FDG-PET images in individual patients produced similar findings to the SPM results. CONCLUSION: This study suggests that brain regions showing a postoperative increase in glucose metabolism appear to represent the propagation pathways of ictal and interictal epileptic discharges in MTLE while a postoperative decrease in glucose metabolism may be related to a permanent loss of afferents from resected anterior-mesial temporal structures.
Anterior Temporal Lobectomy ; Brain ; Caudate Nucleus ; Electrons ; Epilepsy, Temporal Lobe* ; Glucose ; Gyrus Cinguli ; Humans ; Magnetic Resonance Imaging ; Mesencephalon ; Metabolism ; Pathology ; Pulvinar ; Sclerosis ; Seizures ; Temporal Lobe* ; Thalamus