Article

Although a mainstay of clinical sensory examination after damage in
the spinal cord, pinprick sensation represents only one afferent modality
conveyed in the spinothalamic tract. As an objective outcome, complementary
information regarding spinothalamic tract conduction may be elucidated by
measuring contact heat evoked potentials (CHEPs). Objective. To assess the value
of CHEPs to measure spinothalamic tract function in spinal cord disorders
compared with pinprick scoring. Methods. CHEPs were examined using a standard (35
degrees C) and increased baseline (42 degrees C) contact heat temperature.
Pinprick sensation was rated as absent, impaired, or normal according to the
International Standards for the Neurological Classification of Spinal Cord
Injury. Results. Fifty-nine dermatomes above, at, and below the sensory level of
impairment were analyzed in 37 patients with defined spinal cord disorder. In
dermatomes with absent or impaired pinprick sensation, CHEPs using a standard
baseline temperature were mainly abolished (3/16 and 8/35, respectively).
However, when applying an increased baseline temperature, CHEPs became recordable
(absent: 11/16; impaired: 31/35). Furthermore, CHEPs with increased baseline
temperature allowed discerning between dermatomes with absent, impaired, and
normal pinprick sensation when using an objective measure (ie, N2P2 amplitude).
In contrast, the pain perception to contact heat stimulation was independent of
pinprick scores. Conclusion. Applying pinprick testing is of limited sensitivity
to assess spinothalamic tract function in spinal cord disorders. The application
of CHEPs (using standard and increased baseline temperatures) as an objective
readout provides complementary information of spinothalamic tract functional
integrity beyond pinprick testing.
CI - (c) The Author(s) 2013.

Langue : ANGLAIS