A method for assessing recovery of fine motor function of the hand in a rhesus monkey model of cortical injury: an adaptation of the Fugl-Meyer Scale and Eshkol-Wachman Movement Notation

Mesenchymal-derived extracellular vesicles enhance microglia-mediated synapse remodeling after cortical injury in aging Rhesus monkeys

Understanding the microglial neuro-immune interactions in the primate brain is vital to developing therapeutics for cortical injury, such as stroke or traumatic brain injury. Our previous work showed that mesenchymal-derived extracellular vesicles (MSC-EVs) enhanced motor recovery in aged rhesus monkeys following injury of primary motor cortex (M1), by promoting homeostatic ramified microglia, reducing injury-related neuronal hyperexcitability, and enhancing synaptic plasticity in perilesional cortices. A focal lesion was induced via surgical ablation of pial blood vessels over lying the cortical hand representation of M1 of aged female rhesus monkeys, that received intravenous infusions of either vehicle (veh) or EVs 24 h and again 14 days post-injury. The current study used this same cohort to address how these injury- and recovery-associated changes relate to structural and molecular interactions between microglia and neuronal synapses. Using multi-labeling immunohistochemistry, high-resolution microscopy, and gene expression analysis, we quantified co-expression of synaptic markers (VGLUTs, GLURs, VGAT, GABARs), microglia markers (Iba1, P2RY12), and C1q, a complement pathway protein for microglia-mediated synapse phagocytosis, in perilesional M1 and premotor cortices (PMC). We compared this lesion cohort to age-matched non-lesion controls (ctr). Our findings revealed a lesion-related loss of excitatory synapses in perilesional areas, which was ameliorated by EV treatment. Further, we found region-dependent effects of EVs on microglia and C1q expression. In perilesional M1, EV treatment and enhanced functional recovery were associated with increased expression of C1q + hypertrophic microglia, which are thought to have a role in debris-clearance and anti-inflammatory functions. In PMC, EV treatment was associated with decreased C1q + synaptic tagging and microglia-spine contacts. Our results suggest that EV treatment may enhance synaptic plasticity via clearance of acute damage in perilesional M1, and thereby preventing chronic inflammation and excessive synaptic loss in PMC. These mechanisms may act to preserve synaptic cortical motor networks and a balanced normative M1/PMC synaptic function to support functional recovery after injury.

Neural recovery after cortical injury: Effects of MSC derived extracellular vesicles on motor circuit remodeling in rhesus monkeys

Reorganization of motor circuits in the cortex and corticospinal tract are thought to underlie functional recovery after cortical injury, but the mechanisms of neural plasticity that could be therapeutic targets remain unclear. Recent work from our group have shown that systemic treatment with mesenchymal stem cell derived (MSCd) extracellular vesicles (EVs) administered after cortical damage to the primary motor cortex (M1) of rhesus monkeys resulted in a robust recovery of fine motor function and reduced chronic inflammation. Here, we used immunohistochemistry for cfos, an activity-dependent intermediate early gene, to label task-related neurons in the surviving primary motor and premotor cortices, and markers of axonal and synaptic plasticity in the spinal cord. Compared to vehicle, EV treatment was associated with a greater density of cfos⁺ pyramidal neurons in the deep layers of M1, greater density of cfos⁺ inhibitory interneurons in premotor areas, and lower density of synapses on MAP2+ lower motor neurons in the cervical spinal cord. These data suggest that the anti-inflammatory effects of EVs may reduce injury-related upper motor neuron damage and hyperexcitability, as well as aberrant compensatory re-organization in the cervical spinal cord to improve motor function.

Comparing the Effects of Short-Term Liuzijue Exercise and Core Stability Training on Balance Function in Patients Recovering From Stroke: A Pilot Randomized Controlled Trial

Aims

Liuzijue Qigong (LQG) exercise is a traditional Chinese exercise method in which breathing and pronunciation are combined with movement guidance. Breathing is closely related to balance, and LQG, as a special breathing exercise, can be applied to balance dysfunction after stroke. The purpose of this study was to observe the clinical effects of short-term LQG exercise on balance function in patients recovering from stroke.

Methods

Stroke patients were randomly divided into an Intervention Group (IG) (n = 80) and a Control Group (CG) (n = 80). The IG received conventional rehabilitation training plus LQG and the CG received conventional rehabilitation training plus Core Stability Training (CST). All patients received treatment once a day, 5 times a week for 2 weeks. The primary outcome was Berg Balance Scale (BBS). Secondary outcome measures were static standing and sitting balance with eyes open and closed, Fugl-Meyer Assessment (FMA), Maximum Phonation Time (MPT), Modified Barthel Index (MBI) and diaphragm thickness and mobility during quiet breath (QB) and deep breath (DB).

Results

Compared with the CG, the IG showed significant improvement in the BBS (10.55 ± 3.78 vs. 9.06 ± 4.50, P = 0.039), MPT (5.41 ± 4.70 vs. 5.89 ± 5.24, P = 0.001), MBI (12.88 ± 6.45 vs. 10.00 ± 4.84, P = 0.003), diaphragmatic mobility during QB (0.54 ± 0.73 vs. 0.33 ± 0.40, P = 0.01) and diaphragmatic mobility during DB (0.99 ± 1.32 vs. 0.52 ± 0.77, P = 0.003), Cop trajectory in the standing position with eyes open (−108.34 ± 108.60 vs. −89.00 ± 140.11, P = 0.034) and Cop area in the standing positions with eyes open (−143.79 ± 431.55 vs. −93.29 ± 223.15, P = 0.015), Cop trajectory in the seating position with eyes open (−19.95 ± 23.35 vs. −12.83 ± 26.64, P = 0.001) and Cop area in the seating position with eyes open (−15.83 ± 9.61 vs. −11.29 ± 9.17, P = 0.002).

Conclusions

The short-term LQG combined with conventional rehabilitation training significantly improved the balance functions of stroke patients. It also improved static standing and sitting balance with the eyes open, diaphragm functions, maximum phonation time and the quality of daily life for stroke patients.

Clinical Trial Registration

http://www.chictr.org.cn/edit.aspx?pid=25313&htm=4, Identifier: ChiCTR1800014864.

Sex differences in recovery of motor function in a rhesus monkey model of cortical injury

BACKGROUND

Stroke disproportionately affects men and women, with women over 65 years experiencing increased severity of impairment and higher mortality rates than men. Human studies have explored risk factors that contribute to these differences, but additional research is needed to investigate how sex differences affect functional recovery and hence the severity of impairment. In the present study, we used our rhesus monkey model of cortical injury and fine motor impairment to compare sex differences in the rate and degree of motor recovery following this injury.

METHODS

Aged male and female rhesus monkeys were trained on a task of fine motor function of the hand before undergoing surgery to produce a cortical lesion limited to the hand area representation of the primary motor cortex. Post-operative testing began two weeks after the surgery and continued for 12 weeks. All trials were video recorded and latency to retrieve a reward was quantitatively measured to assess the trajectory of post-operative response latency and grasp pattern compared to pre-operative levels.

RESULTS

Postmortem analysis showed no differences in lesion volume between male and female monkeys. However, female monkeys returned to their pre-operative latency and grasp patterns significantly faster than males.

CONCLUSIONS

These findings demonstrate the need for additional studies to further investigate the role of estrogens and other sex hormones that may differentially affect recovery outcomes in the primate brain.

Nursing effects of finger exercise on cognitive function and others for cerebral ischemic stroke patients

OBJECTIVE

To investigate the nursing effects of finger exercise training on cognitive function and others for patients with cerebral ischemic stroke (CIS).

METHODS

A total of 200 patients with CIS were selected in this prospective study. According to the random number table method, they were divided into control group (n=100, routine nursing) and research group (n=100, routine nursing combined with finger exercise training). Various scales were used to evaluate the cognitive function, hand function, upper limb motor function, wrist flexor muscle tone, degree of neurological impairment and ability of daily living (ADL) in the two groups before and after intervention. And the incidence of mild vascular cognitive impairment (VCI) after intervention was compared.

RESULTS

After intervention, Montreal Cognitive Assessment (MoCA), Mini Mental State Examination (MMSE), hand function, Fugl-meyer Assessment (FMA) and ADL scores in both groups were significantly increased, and those in the research group were significantly higher than those in the control group (all P<0.05). There were opposite trends in the Neurologic Functional Defect (NIHSS) and Modified Ashworth Scale (MAS) for wrist flexor scores (all P<0.05). The incidence of mild VCI in the research group was significantly lower than that in the control group (P<0.05).

CONCLUSION

On the basis of early rehabilitation nursing, combined finger exercise training can improve cognitive function, hand function, upper limb function and ADL for patients with CIS.

Mesenchymal derived exosomes enhance recovery of motor function in a monkey model of cortical injury

BACKGROUND

Exosomes from mesenchymal stromal cells (MSCs) are endosome-derived vesicles that have been shown to enhance functional recovery in rodent models of stroke.

OBJECTIVE

Building on these findings, we tested exosomes as a treatment in monkeys with cortical injury.

METHODS

After being trained on a task of fine motor function of the hand, monkeys received a cortical injury to the hand representation in primary motor cortex. Twenty-four hours later and again 14 days after injury, monkeys received exosomes or vehicle control. Recovery of motor function was followed for 12 weeks.

RESULTS

Compared to monkeys that received vehicle, exosome treated monkeys returned to pre-operative grasp patterns and latency to retrieve a food reward in the first three-five weeks of recovery.

CONCLUSIONS

These results provide evidence that in monkeys exosomes delivered after cortical injury enhance recovery of motor function.