Network change in the ipsilesional cerebellum is correlated with motor recovery following unilateral pontine infarction

Abstract

Background and purpose Patients with acute pontine infarcts generally have good short‐term motor outcomes; however, the mechanisms underlying this recovery of function remain unclear. Methods Twenty well‐recovered patients with acute pontine infarcts and 20 well‐recovered patients with acute striato‐capsular infarcts were recruited. Fugl‐Meyer assessment and resting‐state functional magnetic resonance imaging were performed 1, 4 and 12 weeks after onset. Patients were further assigned to better and worse recovery subgroups according to the degree of motor recovery at the twelfth week after stroke. Voxel‐wise degree centrality (DC)–behavior correlation analysis was used to identify brain regions related to changes in motor function within 12 weeks after stroke. Results A significant correlation was found between DC and Fugl‐Meyer scores within 12 weeks in the ipsilesional cerebellar crus I and crus II in patients with pontine infarction and in the ipsilesional middle temporal gyrus in patients with striato‐capsular infarction (all P < 0.001, AlphaSim corrected). The mean DC in these areas was higher both in the better and worse recovery subgroups at the fourth than at the first week (all P < 0.05). In addition, the mean DC values in these areas were higher in patients with better recovery at the twelfth than at the first week (P < 0.05), but such change was not found in patients with worse recovery. Conclusions These results indicate that network changes in the ipsilesional cerebellum are correlated with motor recovery following pontine infarction. Motor recovery mechanisms may vary between pontine and striato‐capsular infarcts, according to lesion location.

EEG Changes in Time and Time-Frequency Domain During Movement Preparation and Execution in Stroke Patients

“…ERD is considered to reflect movement-related brain activity in the time-frequency domain (Neuper et al, 2006), and the findings in the present study indicate that stroke patients produce a larger range of activation in the motor cortex than healthy subjects during movement preparation and execution. This phenomenon also supports the ipsilateral compensation and adjacent-region compensation mechanism in the stroke rehabilitation process that was proposed by previous research using animal models (Starkey et al, 2012;Liu et al, 2019). Although all participants were told to start moving after the GO signal, given the visual cue, a larger motor cortex area was activated in each patient's brain right after the cue.…”

“…During unilateral extremity movements, brain activation was observed to be the strongest in the contralesional motor cortical area in the early stage of a stroke. When the movement pattern gradually normalized through recovery, the brain activation center gradually shifted back to the lesioned side (Liu et al, 2019). Contralesional compensation of the motor cortex showed a positive correlation with the severity of brain damage (Dijkhuizen et al, 2001(Dijkhuizen et al, , 2003Hsu and Jones, 2006).…”

“…Understanding the brain activity changes in the motor cortex during movement preparation and execution is critical for the study of brain plasticity and develop rehabilitation strategies for stroke patients. Animal experiments suggested that after stroke, the central nervous system generates recovery through reconstruction mechanisms such as contralesional hemisphere compensation (Liu et al, 2019), activation of the brain structures surrounding damage, and redistribution of the cortical representative regions (Hara, 2015). The motor cortex was reported to show laterality changes after stroke.…”

Machine Learning for Predicting Motor Improvement After Acute Subcortical Infarction Using Baseline Whole Brain Volumes

“…Inclusion criteria included: (1) first unilateral supratentorial subcortical cerebral infarct (<7 days) without cortical lesions as confirmed by T1-weighed imaging, T2-weighted imaging, and diffusion-weighted imaging (Figure 1); (2) no occlusion of a major artery, as evaluated by ultrasound and magnetic resonance angiography or CT angiography; (3) 18 to 75 years old; (4) an FMA-UE score <66 points 9 ; and (5) have been receiving routine rehabilitation therapies. 7,23-25 Exclusion criteria included: (1) inability to undergo cerebral MRI; (2) any revascularization therapy, including intravenous alteplase or mechanical approaches; (3) traumatic brain injury, epilepsy, Parkinson’s disease, psychiatric diseases, or systemic diseases such as terminal carcinoma, renal failure, and cirrhosis; and (4) any other neurological deficits (aphasia) or use of medications that are likely to affect motor examination outcomes during follow-up.

Figure 1.Lesion maps from participants exhibiting proportional vs poor recovery. All lesions are aligned to the same hemisphere for visualization.

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“…The study protocol of this work was planned as a 12-week longitudinal investigation, with patients undergoing neurological and motor assessments two times after stroke onset: within 1 week after symptom onset (W1, <7 days) and at the end of week 12 (W12, 84 ± 4 days). 7,23-25…”