Sensory perception in complete spinal cord injury

Area of Science:

• Neuroscience
• Clinical Neurology
• Rehabilitation Medicine

Background:

• Spinal cord injury (SCI) often results in a complete loss of function below the injury level.
• Central neuropathic pain is a common complication in SCI patients.
• Understanding retained sensory function is crucial for managing SCI and pain.

Purpose of the Study:

• To investigate sensations perceived by patients with clinically complete spinal cord injury (SCI) when stimulated below the injury level.
• To determine if retained sensory function correlates with pain, spasticity, or spasms.
• To explore the utility of neuroimaging and electrophysiological tests in assessing sensory function across SCI.

Main Methods:

• Quantitative sensory testing (QST) was performed on 24 patients with traumatic SCI (ASIA Grade A).
• Patients were assessed for central neuropathic pain, MR imaging, and somatosensory evoked potentials (SEP).
• Stimuli included painful (pressure, pinch, heat, cold) and repetitive (pinprick) inputs below the injury level.

Main Results:

• Fifty percent of SCI patients reported vague, localized sensations in response to stimuli below the injury level.
• No significant differences in pain, spasticity, or spasms were observed between patients with and without localized sensations.
• SEP and MRI findings did not distinguish between patients who perceived sensations and those who did not.

Conclusions:

• The study suggests that some individuals with complete SCI may possess retained sensory pathways across the injury site.
• This finding challenges the notion of absolute functional disconnection in complete SCI, proposing a 'sensory discomplete' SCI classification.
• Further research is needed to elucidate the mechanisms and clinical implications of this retained sensory communication.