Related Experiment Video
Updated: May 31, 2025
Unilateral Pyramidotomy of the Corticospinal Tract in Rats for Assessment of Neuroplasticity-inducing Therapies
Published on: December 15, 2014
Preservation of Bilateral Corticospinal Projections from Injured Hemisphere After Perinatal Stroke
Cameron P Casey1, Ellen N Sutter1,2, Alina Grimaldo1
1Waisman Center, University of Wisconsin-Madison, Madison, WI 53706, USA.
Insights
This case study shows preserved corticospinal tract (CST) function after severe perinatal stroke. Despite significant motor cortex loss, neural plasticity allowed for functional bilateral CST circuitry development.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Pediatric Neurology
Background:
- Perinatal brain injury, a major cause of developmental disabilities like cerebral palsy, necessitates understanding early brain development post-injury.
- This case report examines longitudinal neuromotor development in a term infant with extensive right-hemispheric tissue loss from unilateral ischemic stroke.
- Focus is on the corticospinal tract (CST) development from the lesioned hemisphere, offering insight into CST development after substantial motor cortex loss.
Observation:
- Neuromotor and neuroimaging assessments (MRI, spTMS) were conducted at 4, 18, and 25 months.
- Diffusion-weighted MRI revealed bilateral CSTs despite 92.7% loss of right motor cortex.
- Single-pulse transcranial magnetic stimulation demonstrated preserved bilateral motor-evoked potentials across all visits.
Findings:
- The lesioned hemisphere showed initial CST integrity increase (Visits 1-2) followed by a decrease (Visits 2-3).
- The non-lesioned hemisphere exhibited increased CST integrity (Visits 1-2) with stability thereafter.
- Neuromotor assessments indicated a high risk for cerebral palsy throughout the study period.
Implications:
- Magnetic resonance imaging (MRI) and single-pulse transcranial magnetic stimulation (spTMS) are valuable tools for studying infant neuromotor development.
- Preserved functional bilateral CST circuitry was observed despite significant unilateral motor cortex loss.
- Distinct developmental trajectories of CST integrity highlight the potential for neural plasticity following perinatal brain injury.
Background:
Perinatal brain injury is a leading cause of developmental disabilities, including cerebral palsy. However, further work is needed to understand early brain development in the presence of brain injury. In this case report, we examine the longitudinal neuromotor development of a term infant following a significant loss of right-hemispheric brain tissue due to a unilateral ischemic stroke. Our analysis focuses on the integrity and development of the corticospinal tract (CST) from the lesioned hemisphere. This case provides a unique opportunity to evaluate CST development after loss of the majority of the motor cortex.
Methods:
Evaluations were conducted when the infant was 4 (Visit-1), 18 (Visit 2), and 25 (Visit 3) months old. Assessments included magnetic resonance imaging (MRI) to characterize the lesion and quantify CST structural integrity, single-pulse transcranial magnetic stimulation (spTMS) to evaluate CST functional circuitry, and neuromotor assessments.
Results:
At Visit 1, bilateral CSTs were identified through diffusion-weighted MRI (dMRI) despite an estimated loss of 92.7% (7.3% retained) of age-typical motor cortex from the right hemisphere. Both hemispheres exhibited bilateral motor-evoked potential in response to stimulation with spTMS, which remained when reassessed at Visits 2 and 3. Longitudinal MRI showed distinct developmental trajectories of CST integrity in each hemisphere, with the lesioned hemisphere exhibiting initial increases in integrity between Visits 1 and 2 followed by a decrease in integrity between Visits 2 and 3. The non-lesioned hemisphere showed increased integrity from Visit 1 to Visit 2, which remained stable at Visit 3. Motor assessments at all visits indicated a high risk of cerebral palsy.
Conclusions:
This report highlights the utility of MRI and spTMS in studying neuromotor development. The findings reveal preserved functional bilateral CST circuitry despite majority loss of the right-hemispheric motor cortex as well as distinct developmental trajectories in CST integrity between hemispheres. These results underscore the potential for neural plasticity after perinatal brain injury.
Clinical Trials Registration:
NCT05013736.
More Related Videos
08:01Compensatory Limb Use and Behavioral Assessment of Motor Skill Learning Following Sensorimotor Cortex Injury in a Mouse Model of Ischemic Stroke
Published on: July 10, 2014
05:56A Mouse Model of Direct Anastomosis via the Prespinal Route for Crossing Nerve Transfer Surgery
Published on: October 19, 2021
Related Concept Videos
01:22Indirect Motor Pathways
The vestibulospinal tract originates in the vestibular nuclei of the brainstem. The vestibular system detects changes in...
01:11Direct Motor Pathways
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and...