Publications by authors named "Mohammadjavad Negahdar"

Article Synopsis
  • The study involved a case series using Yucatan miniature pigs to model spinal cord contusion injuries, comparing findings to human spinal cord injury cases.
  • Researchers aimed to assess MRI measures of spinal cord damage severity and the preservation of key neural tissue, linking these to behavioral outcomes in varying levels of injury severity.
  • Results showed that pigs with more severe injuries had worse locomotor and bladder function outcomes, paralleling findings in human cases, indicating that this pig model can inform understanding of spinal cord injuries and MRI evaluations.
View Article and Find Full Text PDF

Spinal cord epidural stimulation (scES) is an intervention to restore motor function in those with severe spinal cord injury (SCI). Spinal cord lesion characteristics assessed via magnetic resonance imaging (MRI) may contribute to understand motor recovery. This study assessed relationships between standing ability with scES and spared spinal cord tissue characteristics at the lesion site.

View Article and Find Full Text PDF

Previous studies have shown that epidural stimulation of the lumbosacral spinal cord (scES) can re-enable lower limb volitional motor control in individuals with chronic, clinically motor complete spinal cord injury (SCI). This observation entails that residual supraspinal connectivity to the lumbosacral spinal circuitry still persisted after SCI, although it was non-detectable when scES was not provided. In the present study, we aimed at exploring further the mechanisms underlying scES-promoted recovery of volitional lower limb motor control by investigating neuroimaging markers at the spinal cord lesion site magnetic resonance imaging (MRI).

View Article and Find Full Text PDF

We studied relationships of cerebral spinal fluid (CSF) pulsatile flow at cervical, thoracic, and lumbar levels using phase-contrast cine MRI (PCCMRI) to determine the following: ) instantaneous and average net flows at cervical, thoracic, and lumbar levels, ) stochastic correlations of CSF flow with major arterial supplies and major draining veins, and ) whether adjustments of cord-flow curves-using cord cross-sectional areas, caudal lengths, and caudal volumes-would normalize flow curves from different levels. We scanned 15 healthy volunteers without anesthesia, ages 23-46 yr, using external, retrocardiac-gated, two-dimensional PCCMRI at 3T. Transverse scans of the subarachnoid space, arteries, and veins were acquired and analyzed at cervical, thoracic, and lumbar levels.

View Article and Find Full Text PDF