Abstract
Objective: To evaluate the sensitivity of contact heat evoked potentials (CHEPs) compared with dermatomal somatosensory evoked potentials (dSSEPs) and clinical sensory testing in myelopathic spinal cord disorders (SCDs).
Methods: In a prospective cohort study, light-touch (LT) and pinprick (PP) testing was complemented by dermatomal CHEPs and dSSEPs in patients with a confirmed SCD as defined by MRI. Patients with different etiologies (i.e., traumatic and nontraumatic) and varying degrees of spinal cord damage (i.e., completeness) were included. SCD was distinguished into 3 categories according to MRI pattern and neurologic examination: a) complete, b) incomplete-diffuse, and c) central or anterior cord damage.
Results: Seventy-five patients were included (complete n = 7, incomplete-diffuse n = 33, central/anterior n = 35). In total, 319 dermatomes were tested with combined CHEPs and dSSEPs. CHEPs, dSSEPs, and clinical sensory testing were comparably sensitive to detect the myelopathy in complete (CHEPs 100%, dSSEPs 91%, PP and LT 82%) and incomplete-diffuse (CHEPs 92%, dSSEPs and PP 86%, LT 81%, p > 0.05 for all comparisons) cord damage. In central/anterior cord damage, CHEPs showed a significantly higher sensitivity than dSSEPs (89% compared with 24%, p < 0.001) and clinical sensory testing (PP 62%, LT 57%, p < 0.05). A subclinical sensory impairment was detected more frequently by CHEPs than dSSEPs (60% compared with 29%, p = 0.001).
Conclusions: Assessment of spinothalamic pathways with CHEPs is reliable and revealed the highest sensitivity in all SCDs. Specifically in incomplete lesions that spare dorsal pathways, CHEPs are sensitive to complement the clinical diagnosis.
GLOSSARY
- AIS=
- American Spinal Injury Association Impairment Scale;
- AUC=
- area under the receiver operating characteristic curve;
- CHEP=
- contact heat evoked potential;
- dSSEP=
- dermatomal somatosensory evoked potential;
- ISNCSCI=
- International Standards for the Neurological Classification of Spinal Cord Injury;
- LEP=
- laser evoked potential;
- LT=
- light touch;
- NP=
- neuropathic pain;
- PP=
- pinprick;
- ROC=
- receiver operating characteristic;
- SCD=
- spinal cord disorder;
- SCI=
- spinal cord injury;
- SE=
- standard error.
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
Supplemental data at www.neurology.org
- Received May 17, 2012.
- Accepted in final form January 9, 2013.
- © 2013 American Academy of Neurology
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