Assessing the spatial distribution of cervical spinal cord activity during tactile stimulation of the upper extremity in humans with functional magnetic resonance imaging

This study used functional MRI (fMRI) to map the areas of the spinal cord that become active when healthy people are touched on the shoulder or hand. The researchers wanted to see if the activity was mainly on the same side of the spinal cord as the touch and if touching the shoulder activated higher areas of the spinal cord than touching the hand, as expected based on dermatomal maps. The results showed activity mainly on the same side, but it was spread out more than expected, suggesting that the spinal cord's response to touch is complex.

• 1
  Tactile stimulation resulted in activity localized primarily to the ipsilateral hemicord, with the left- and right-sided stimuli having more activation in the respective ipsilateral hemicord.
• 2
  The activity for both stimulation sites was not localized more dorsally but spread across the dorsal and ventral hemicords at the group and subject level.
• 3
  The lateral shoulder and dorsal third digit stimulation activity did not demonstrate a clear superior-inferior localization to their respective spinal cord segments; instead, the activity for both stimuli had a broader than expected distribution.