Evaluating Longitudinal Motor Recovery in Non-Human Primates after Middle Cerebral Artery Occlusion

Abstract Stroke is a leading cause of disability, often resulting in long-term motor impairment that affect quality of life. Non-human primates (NHP) closely resemble human neuroanatomy and physiology, making them valuable for translational stroke research. Neurobehavioral assessment of NHPs following stroke is critical for understanding recovery patterns, evaluating therapeutic interventions, and informing human clinical studies. Non-Human Primate Stroke Scale (NHPSS) is commonly used to assess neurological deficits but lacks specificity in evaluating motor impairments. Robotic assessment tools, such as the Kinesiological Instrumental for Normal and Altered Reaching Movement (Kinarm), provide high-resolution, standardized, and objective quantification of upper limb function. This study aims to investigate the longitudinal sensorimotor recovery of NHPs following Middle Cerebral Artery Occlusion (MCAO) by assessing performance with both NHPSS and Kinarm. Additionally, magnetic resonance imaging (MRI) will be used to confirm stroke morphology, and volume, and examine its relationship with functional recovery. Methods: Two cynomolgus macaques were trained on the Kinarm VGR task to assess sensorimotor function. After stroke induction via transient MCAO, motor performance was reevaluated at multiple time points: Acute, sub-acute and chronic. Performance on the VGR task was compared to NHPSS scores over the long term. Longitudinal data was analyzed to assess the relationship between NHPSS and Kinarm performance, with consideration to maladaptive neuroplasticity. ii Hypothesis 1: NHPSS at 30 days post-MCAO in cynomolgus macaques correlates with long-term neurological deficits measured by Kinarm. Hypothesis 2: Functional recovery in chronic MCA stroke in cynomolgus macaques is more accurately predicted by Kinarm than NHPSS. Results: Following MCAO, the affected limb exhibited deficits in the VRG task. NHPSS scores stabilized after 30 days, while the Kinarm performance continued to show changes over time, indicating Kinarm provides a more detailed measure of motor function and recovery. Conclusions: These investigations reinforce the similarities in stroke-related reaching impairments between NHPs and humans and highlights the value of Kinarm in the NHP model to derive outcome measures that are immediately translatable to human trials. This study validates the use of NHPSS and Kinarm for post-stroke assessment and suggests that a combined approach to post-stroke assessment is beneficial in translational studies. Finally, the long-term recovery followed by loss of function following periods of non-assessment suggests that, like humans, NHPs lose function of the affected limb due to maladaptive plasticity.

Department dc:contributor.department

Neuroscience Studies

Year dc:date.issued

2026

Author dc:creator

• Schincariol, Emma

Advisor dc:contributor.supervisor

• Cook, DJ

• NHP
• primate
• stroke
• kinarm

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1974/36151

OAI identifier oai:identifier

oai:queensu.scholaris.ca:1974/36151