Voxel-Based Mapping of Brain Hypometabolism in Permanent Amnesia with PET

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2001-06, Vol.13 (6), p.1164-1173
• Main Authors: Aupée, A.M., Desgranges, B., Eustache, F., Lalevée, C., de la Sayette, V., Viader, F., Baron, J.C.
• Format: Article
• Language: English
• Subjects: 18 F-FDG; Adult; Amnesia; Amnesia - diagnostic imaging; Amnesia - physiopathology; Blood Glucose - metabolism; Brain - diagnostic imaging; Brain - physiopathology; Brain Mapping; Cerebral Cortex - diagnostic imaging; Cerebral Cortex - physiopathology; Cortex (cingulate); Cortex (temporal); Dominance, Cerebral - physiology; Energy Metabolism - physiology; Etiology; FDG; Female; glucose utilization; Hemispheric laterality; Humans; hypometabolism network; Hypoxia, Brain - diagnostic imaging; Hypoxia, Brain - physiopathology; Korsakoff Syndrome - diagnostic imaging; Korsakoff Syndrome - physiopathology; Male; memory; Metabolic rate; Middle Aged; Nerve Net - diagnostic imaging; Nerve Net - physiopathology; permanent amnesia; PET; Positron emission tomography; Prefrontal cortex; Retrograde amnesia; Thalamus; Thalamus - diagnostic imaging; Thalamus - physiopathology; Tomography, Emission-Computed; Wernicke Encephalopathy - diagnostic imaging; Wernicke Encephalopathy - physiopathology
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1006/nimg.2001.0762

In this study, we used voxel-based mapping methods to compare the resting cerebral metabolic rate of glucose (CMRglc) measured with PET in five patients with permanent amnesia (three with chronic Wernicke-Korsakoff and two with postanoxia syndrome) to that of nine healthy age-matched subjects. We assessed (i) a group pattern of relative hypometabolism; and (ii) the consistency of this group pattern, if any, in individual subjects, according to etiology. The results from the group analysis documented that permanent amnesia is associated with hypometabolism in the thalamus, posterior cingulate cortex, and mesial prefrontal cortex (near the anterior cingulate gyrus), bilaterally, as well as in the left supramarginal and middle temporal gyri. The individual analysis showed that this group pattern was found in essentially each patient, regardless of the cause of amnesia. Thus, permanent amnesia is subtended by dysfunction in structures belonging to Papez/limbic circuits as well as in left-hemisphere areas typically concerned with verbal functions, probably through a mechanism of thalamo-cortical disconnection and possibly involved in retrograde amnesia. The use of a voxel-based method allowed us to map a common network of synaptic dysfunction in a neuropsychological syndrome regardless of etiology. Our results indicate that this should be a powerful method in functional neuropsychology.