Early Warning Value of ASL-MRI to Estimate Premorbid Variations in Patients With Early Postoperative Cognitive Dysfunctions

Abstract

Background: Postoperative cognitive dysfunction (POCD) is a general complication following cardiac and major non-cardiac surgery amongst the elderly, yet its causes and mechanisms are still unknown. The present study aimed to detect whether regional cerebral blood flow (CBF) is altered in the brain before surgery in POCD patients compared with non-POCD (NPOCD) patients, thus, CBF variation may potentially predict the occurrence of early POCD.Methods: Fifty patients scheduled for spinal stenosis surgery were enrolled in the study. All study participants completed a battery of neuropsychological tests (NPTs) by a well-trained neuropsychologist before the surgery and 1 week after the surgery. POCD was defined when the preoperative to postoperative difference of at least two of the NPTs’ |Z|-scores with reference to a control group exceeded 1.96. Pulsed arterial spin-labeling (ASL) MRI was scanned at least 1 day before surgery. The ASLtbx toolkit and SPM12 were applied to preprocess and correct the images, which were then normalized to the MNI brain template space to obtain standardized cerebral perfusion images.Results: POCD was identified in 11 out of 50 patients (22%). The CBF of the right superior temporal lobe, right and left middle cingulate gyrus, and the right hippocampus, and parahippocampal gyrus in POCD group was lower than that in NPOCD group (P < 0.001). The CBF of the pars triangularis of inferior frontal gyrus in POCD group was higher than that in NPOCD group (P < 0.001).Conclusions: These preliminary findings suggest that CBF premorbid alterations may happen in cognitively intact elderly patients that develop early POCD. Alterations of preoperative CBF might be a bio-marker for early POCD that can be detected by noninvasive MRI scans.

Does cognitive frailty predict delayed neurocognitive recovery after noncardiac surgery in frail elderly individuals? Probably not

“…Patients were first screened with MMSE and MoCA to eliminate those with dementia and identify those with MCI, respectively. Furthermore, eight tests with 11 subscales were administered, including the Hopkins Verbal Learning Test (HVLT immediate and delayed), Brief Visuospatial Memory Test-revised (BVMT immediate and delayed), Digits Symbol Substitution Test (DSST), Trail Making Test (TMT), Semantic Fluency Test (SFT), Forward and Backward Digit Span Test (DST forward and backward), Stroop Color Word Test (STROOP), and Judgment Of Line Orientation Test (JLOT), mainly focusing on memory, attention force, and executive function, as was the case in our previous study (Du et al, 2021 ). These measures were not only highly sensitive to the many forms of cognitive impairment but also free of cultural bias.…”

“…All the tests were conducted in a quiet environment by professionally trained personnel. DNR was defined as a Z score (at least two Z-scores in individual tests, or the composite Z-score of all variables) at ≥ 1.96, as described in the International Study of Post-Operative Cognitive Dysfunction (ISPOCD) before (Moller et al, 1998 ; Du et al, 2021 ).…”

“…In contrast, participants were considered to have MCI if their MoCA scores were < 26 points (Nasreddine et al, 2005). (Du et al, 2021). These measures were not only highly sensitive to the many forms of cognitive impairment but also free of cultural bias.…”

Potential Markers of Neurocognitive Disorders After Cardiac Surgery: A Bibliometric and Visual Analysis

“…In order to improve identification and prevention of these neurocognitive sequelae, many researchers have been seeking potential markers with high sensitivity and specificity (Alifier et al, 2020 ; Szwed et al, 2020 ; Du et al, 2021 ). As an objective parameter, markers can capture complex pathophysiological changes of bodies, assist in risk stratification and prognosis monitoring, and facilitate diagnosis and assessment of PNDs.…”