BACKGROUND: Brain glucose metabolic rates measured by positron emission tomography can be more affected by partial volume effects in Alzheimer disease (AD) than in healthy aging because of disease-associated brain atrophy. OBJECTIVE: To determine whether the distinct distribution of cerebral metabolic lesions in patients with the visual variant of AD (AD + VS) represents a true index of neuronal/synaptic dysfunction or is the consequence of brain atrophy. SETTING: Government research hospital. DESIGN: Resting cerebral metabolic rate for glucose was measured with positron emission tomography in a cross-sectional study of AD and AD + VS groups and in healthy control subjects. Segmented magnetic resonance images were used to correct for brain atrophy. PATIENTS: Patients with AD + VS had prominent visual and visuospatial symptoms. There were 15 patients with AD, 10 with AD + VS, and 37 age-matched control subjects. MAIN OUTCOME MEASURE: Measurement of the rate of cerebral glucose metabolism. RESULTS: Before atrophy correction, the AD + VS group, compared with the control subjects, showed hypometabolism in primary and extrastriate visual areas and in parietal and superior temporal cortical areas. Compared with the AD group, the AD + VS group showed hypometabolism in visual association areas. After atrophy correction, hypometabolism remained significantly different between patients and controls and between the 2 AD groups. CONCLUSIONS: The reductions in cerebral hypometabolism represent a true loss of functional activity and are not simply an artifact caused by brain atrophy. The different patterns of hypometabolism indicate the differential development of the lesions between the AD and AD + VS groups.
BACKGROUND: Brain glucose metabolic rates measured by positron emission tomography can be more affected by partial volume effects in Alzheimer disease (AD) than in healthy aging because of disease-associated brain atrophy. OBJECTIVE: To determine whether the distinct distribution of cerebral metabolic lesions in patients with the visual variant of AD (AD + VS) represents a true index of neuronal/synaptic dysfunction or is the consequence of brain atrophy. SETTING: Government research hospital. DESIGN: Resting cerebral metabolic rate for glucose was measured with positron emission tomography in a cross-sectional study of AD and AD + VS groups and in healthy control subjects. Segmented magnetic resonance images were used to correct for brain atrophy. PATIENTS: Patients with AD + VS had prominent visual and visuospatial symptoms. There were 15 patients with AD, 10 with AD + VS, and 37 age-matched control subjects. MAIN OUTCOME MEASURE: Measurement of the rate of cerebral glucose metabolism. RESULTS: Before atrophy correction, the AD + VS group, compared with the control subjects, showed hypometabolism in primary and extrastriate visual areas and in parietal and superior temporal cortical areas. Compared with the AD group, the AD + VS group showed hypometabolism in visual association areas. After atrophy correction, hypometabolism remained significantly different between patients and controls and between the 2 AD groups. CONCLUSIONS: The reductions in cerebral hypometabolism represent a true loss of functional activity and are not simply an artifact caused by brain atrophy. The different patterns of hypometabolism indicate the differential development of the lesions between the AD and AD + VS groups.
Authors: Kewei Chen; Napatkamon Ayutyanont; Jessica B S Langbaum; Adam S Fleisher; Cole Reschke; Wendy Lee; Xiaofen Liu; Dan Bandy; Gene E Alexander; Paul M Thompson; Leslie Shaw; John Q Trojanowski; Clifford R Jack; Susan M Landau; Norman L Foster; Danielle J Harvey; Michael W Weiner; Robert A Koeppe; William J Jagust; Eric M Reiman Journal: Neuroimage Date: 2011-01-27 Impact factor: 6.556
Authors: Jennifer L Whitwell; Clifford R Jack; Kejal Kantarci; Stephen D Weigand; Bradley F Boeve; David S Knopman; Daniel A Drubach; David F Tang-Wai; Ronald C Petersen; Keith A Josephs Journal: Neurobiol Aging Date: 2006-06-23 Impact factor: 4.673
Authors: Qiaoling Zeng; Xiaojun Guan; Jason C F Law Yan Lun; Zhujing Shen; Tao Guo; Min Xuan; Quanquan Gu; Xiaojun Xu; Min Chen; Minming Zhang Journal: Neurosci Bull Date: 2017-08-21 Impact factor: 5.203