Research on spontaneous upper limb activity and graph theory of electroencephalogram in patients with acute ischemic stroke

To evaluate the changes in motor function impairment and brain functional networks of patients with acute ischemic stroke(AIS) through parameters of spontaneous activities of both upper limbs and electroencephalogram graph theory analysis methods.

The data of 34 acute ischemic stroke patients(observation group) with upper limb motor disorders who were treated in the Department of Neurology of the Affiliated Hospital of Southwest Medical University from January 2022 to October 2023, and 40 healthy controls (HC group) were collected. The subjects completed the National Institutes of Health Stroke Scale (NIHSS) and Fugl-Meyer Assessment (FMA) within 7 days, and wore wrist activity recorders (Actiwatch) continuously for 24 hours to collect data on spontaneous activities of upper limbs and analyzed related parameters such as the coordination coefficient of both upper limbs (r), the activity ratio of the affected side to the healthy side upper limb (ULAR), etc. At the same time, all subjects completed approximately 2 hours of 19-channel electroencephalogram examination. After preprocessing the electroencephalogram data, 5 segments of 10-second resting-state electroencephalogram were extracted for graph theory.

① Compared to healthy individuals, AIS patients exhibited decreased functional connectivity edges in the δ and θ bands, with substantial reductions in network connections in the α band. In the β band, connections between the frontal, right parietal, and occipital regions weakened, while connections from the right temporal lobe to the left temporal lobe strengthened. In the γ band, there was a significant increase in connections throughout the brain. ② Graph theory analysis revealed significantly increased shortest path lengths (α band: t=2.228, P < 0.05, d=-0.52; β band: t=-3.641, P < 0.01, d=-0.878) and decreased global efficiency (α band: t=2.535, P < 0.05, d=0.591; β band: t=3.321, P < 0.01, d=0.803) in the observation group compared to the control group. In the γ band, local efficiency (t=3.279, P < 0.01, d=0.765) and clustering coefficients were significantly higher (t=3.358, P < 0.01, d=0.783). ③ In the γ band, the ULAR≤30% group showed significantly reduced shortest path length (t=-2.063, P < 0.05, d=-0.802) and increased global efficiency (t=2.226, P < 0.05, d=0.865), local efficiency (t=2.95, P < 0.05, d=1.147), and clustering coefficient (t=2.962, P < 0.05, d=1.148). ④ In the observation group, the bilateral upper limb coordination coefficient during sleep was negatively correlated with NIHSS scores (r=-0.389, P < 0.05) and ULAR (r=-0.395, P < 0.05), while FMA scores were positively correlated with ULAR (r=0.442, P < 0.05).

The parameters of spontaneous activities of the upper limbs can be used to determine the impairment of motor function in AIS patients. The combination of changes in brain functional networks and motor impairments can provide new ideas for the study of their neural network mechanisms.