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Differences in spinothalamic function of cervical and thoracic dermatomes: insights using contact heat evoked
Jenny S Haefeli1, Julia Blum, John D Steeves
1Spinal Cord Injury Center, University Hospital Balgrist, Zurich, Switzerland. jhaefeli@paralab.balgrist.ch
Summary
Contact heat evoked potentials (CHEPs) can assess sensory function by spinal cord segment. CHEP amplitudes and pain perception decrease with distance from the spinal cord, requiring topographical consideration in clinical assessments.
Area of Science:
- Neuroscience
- Clinical Electrophysiology
- Sensory Physiology
Background:
- Contact heat evoked potentials (CHEPs) offer a method to evaluate sensory function and nociception from individual spinal cord segments.
- Assessing conduction along the spinothalamic tract is crucial for understanding sensory deficits post-spinal cord injury.
Purpose of the Study:
- To investigate the influence of stimulation site (dermatomes) on CHEPs and thermal perception.
- To compare CHEP responses and pain perception across different dermatomes in healthy subjects of varying ages.
Main Methods:
- Evaluated CHEPs and thermal thresholds in 19 healthy adults across five dermatomes (C4, C5, C6, C8, T4).
- Subjects were divided into younger and older age groups to assess age-related differences.
- Utilized cortical source density analysis to examine brain activity patterns.
Main Results:
- CHEP amplitudes and perceived pain/thermal thresholds decreased from proximal (C4, T4) to distal (C6, C8) dermatomes.
- Cortical source density analysis revealed similar distributions between C4 and C8, with higher densities noted for C4.
- Proximodistal differences in CHEPs and pain perception were observed, influenced by conduction distance and nociceptor distribution.
Conclusions:
- CHEPs are a viable tool for assessing specific dermatomes and spinal cord segments.
- Topographical variations in CHEPs and pain perception must be considered for accurate clinical assessment.
- Findings highlight the importance of accounting for proximodistal differences in clinical evaluations of sensory function.
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