Premium
P4‐365: Posterior compensatory network mediates spatial working memory in those with proficient cognition despite hippocampal atrophy
Author(s) -
Valenzuela Michael,
Turner Andrew,
Kochan Nicole,
Wen Wei,
McIntosh Randy,
Sachdev Perminder,
Breakspear Michael
Publication year - 2011
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2011.09.179
Subject(s) - hippocampal formation , hippocampus , atrophy , neuroscience , working memory , psychology , cognition , spatial memory , neuropsychology , population , episodic memory , cognitive psychology , medicine , pathology , environmental health
ingmultichannel near infrared spectroscopy (NIRS), wemeasured changes in the oxidized hemoglobin level (oxy-Hb) while performing a task reflecting cognitive function, ’shiritori (Japanese word-chain game)’. Methods: The subjects were 250 participants receiving the ’forgetfulness checkup’ performed in 2009 and 2010. The subjects were classified by the physicians in charge based on the checkup results into 4 groups (healthy, lowand high-risk, intermediate, and dementia groups). Regarding cerebral blood flow, oxy-Hb changes were recorded in 44 bilateral regions using multichannel NIRS (Hitachi ETG 4000). Each subject was instructed to say ’a-i-u-e-o ’ for 50 seconds as a resting state and then continuously perform ’shiritori’ for 30 seconds as a task. The resting state and task were alternately repeated 5 times. Oxy-Hb changes from the resting statewere numerically presented every 100 ms. The approximate area while performing the task (doxy-Hb) was calculated and regarded as a variation index. The region of interest (ROI) was set in the region assumed to reflect attention executive function (left ch11). The total the number of chained words in five performances was regarded as the number of ’shiritori’. Informed consent was obtained from all subjects before study. This study was approved by the Kurume University Ethics Committee. Results: Revised Hasegawa’s Dementia Scale (HDS-R) scores in the dementia, highand low-risk, intermediate, and healthy groups were 19.56 3.7, 23.36 1.5, 26.56 1.4, and 28.96 0.9, respectively. The number of ’shiritori’ was 26.16 12.5, 31.86 10.7, 38.56 12.3, and 41.36 12.8 in the dementia, highand low-risk, intermediate, and healthy groups, respectively, showing that it was significantly greater in the healthy and low-risk groups than in the dementia group. In addition, a positive correlation was observed between doxy-Hb at the left ch11 and the number of ‘shiritori”. A significant correlation was also observed between the HDS-R score and doxy-Hb at the left ch11. Conclusions: Evaluation employing the ’shiritori’ task and multichannel NIRS is noninvasive and may be useful for the diagnosis and early discovery of dementia.