Functional MR imaging and traumatic paraplegia: preliminary report.

Area of Science:

• Neuroscience
• Clinical Neurology
• Medical Imaging

Background:

• Paraplegia, resulting from spinal cord injury, often leads to complete loss of motor and sensory function in the lower limbs.
• Assessing residual neural activity in the sensorimotor cortex is crucial for understanding recovery potential and developing therapeutic strategies.

Purpose of the Study:

• To investigate residual functional activity within the sensorimotor cortex of the lower limbs in individuals with complete paraplegia.
• To determine if attempted movements or mental imagery can elicit neural responses in the affected sensorimotor areas.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed in 5 patients with complete paralysis (ASIA A) following traumatic spinal cord injury.
• fMRI paradigms included attempted toe movements, mental imagery of toe movements, and passive proprioceptive stimulation of the toes.
• Control fMRI scans assessed sensorimotor cortex activity during hand movements and stimulation.

Main Results:

• Sensorimotor cortex, premotor cortex, and supplementary motor area (SMA) showed activation during attempted and imagined lower limb movements.
• Passive somatosensory stimulation elicited responses posterior to the central sulcus in 2 patients.
• Control studies demonstrated expected sensorimotor cortex activation during hand tasks.

Conclusions:

• Attempting to move or mentally evoking movement can generate activity in the sensorimotor cortex of the lower limbs, even in clinically complete paraplegia.
• fMRI findings indicate the persistence of sensory anatomical conduction pathways, which can be corroborated by Somatosensory Evoked Potentials (SEPs).
• These results highlight the potential for neuroplasticity and residual function in the sensorimotor system post-spinal cord injury.