Neural Correlates of Cognitive Dysfunctions in Cervical Spondylotic Myelopathy Patients: A Resting-State fMRI Study

Abstract

Cervical spondylotic myelopathy (CSM) is a common disease of the elderly that is characterized by gait instability, sensorimotor deficits, etc. Recurrent symptoms including memory loss, poor attention, etc. have also been reported in recent studies. However, these have been rarely investigated in CSM patients. To investigate the cognitive deficits and their correlation with brain functional alterations, we conducted resting-state fMRI (rs-fMRI) signal variability. This is a novel indicator in the neuroimaging field for assessing the regional neural activity in CSM patients. Further, to explore the network changes in patients, functional connectivity (FC) and graph theory analyses were performed. Compared with the controls, the signal variabilities were significantly lower in the widespread brain regions especially at the default mode network (DMN), visual network, and somatosensory network. The altered inferior parietal lobule signal variability positively correlated with the cognitive function level. Moreover, the FC and the global efficiency of DMN increased in patients with CSM and positively correlated with the cognitive function level. According to the study results, (1) the cervical spondylotic myelopathy patients exhibited regional neural impairments, which correlated with the severity of cognitive deficits in the DMN brain regions, and (2) the increased FC and global efficiency of DMN can compensate for the regional impairment.

Altered Coupling Between Resting-State Cerebral Blood Flow and Functional Connectivity Strength in Cervical Spondylotic Myelopathy Patients

“…High global efficiency of the default mode network positively correlates with MoCA scores in CSM patients. This implies that the high global efficiency in the default mode network compensates for the local impairment (measured by signal variability) in the default mode network ( 19 ). As the hippocampus has been shown to be an important brain region participating in many cognitive functions, the high FCS in the hippocampus was also associated with compensatory or adaptive changes in CSM, necessary for maintaining normal cognitive function in these individuals.…”

“…Therefore, to better explore functional or structural alterations in CSM patients, 12 regions of interest (ROIs) were selected for further analysis. They included the left and right precentral gyrus, the left and right postcentral gyrus, the left and right supplementary motor area, the left and right calcarine gyrus, the left and right precuneus, and the left and right thalamus ( 7 , 12 , 19 , 56 , 57 ). The ROIs were described based on the corresponding brain areas defined in the AAL.…”

“…Assessment of functional alterations in CSM patients relies on regional homogeneity (ReHo), amplitude of low frequency fluctuation (ALFF), and functional connectivity (FC). These methods have revealed extensive functional reorganizations including regional alterations of specific brain regions (e.g., S1, M1, V1) (7,(12)(13)(14), circuits (e.g., the thalamus-cortical circuit) (15,16), subnetworks (e.g., the sensorimotor network and default mode network) (8,(17)(18)(19), and the whole brain network (8) in CSM patients. Among the aforementioned neuroimaging metrics based on fMRI technique, FC is the most widely used for exploring brain functional reorganization in CSM patients.…”

Dynamic and Static Amplitude of Low-Frequency Fluctuation Is a Potential Biomarker for Predicting Prognosis of Degenerative Cervical Myelopathy Patients: A Preliminary Resting-State fMRI Study

“…Therefore, a sensorimotor mask was acquired from Shirer et al ( 25 ) (the spatial distribution of the mask was shown in Supplementary Figure 1 ). MVPA was then applied within the sensorimotor cortices given that previous literature reports of cortical alterations of DCM were mainly located at the sensorimotor network ( 9 , 26 – 29 ).…”

Identification and Therapeutic Outcome Prediction of Cervical Spondylotic Myelopathy Based on the Functional Connectivity From Resting-State Functional MRI Data: A Preliminary Machine Learning Study

“…Only the healthy subjects with no evidence of spinal compression, no ocular disease, no other spinal or brain neurological disorders or systemic disease, and able to complete the fMRI studies were included-details of study participants were as per our previous study (31). In the second dataset (dataset 2), 26 CSM patients and 36 HCs sampled from 2019 to 2020 were recruited in our study using the inclusion criteria for the first dataset; details of study participants were as per our previous study (32). Therefore, a total of 53 CSM patients and 47 healthy participants were included in our current study.…”