Reduced cold pressor pain tolerance in non-recovered whiplash patients: a 1-year prospective study.
Whiplash injury and chronic whiplash syndrome represent major health problems in certain western communities, pain being the main symptom. Sensitization of the nociceptive system may play a role for non-recovery after whiplash injury.


OBJECTIVE
This study examined if tolerance to endure pain stimuli may predict outcome in whiplash injury. In a prospective fashion, 141 acute whiplash patients exposed to rear-end car collision (WAD grade 1-3) and 40 ankle-injured controls were followed and exposed to a cold pressor test, respectively, 1 week, 1, 3, 6 and 12 months after the injury. VAS score of pain and discomfort was obtained before, during and after immersion of the dominant hand into cold water for 2 min. The McGill Pain Questionnaire showed that ankle-injured controls had higher initial pain scores than the corresponding whiplash group, while whiplash-injured subjects had higher scores at 6 months; pain scores being similar at other time points. No difference was found in cold pressor pain between recovered whiplash patients and ankle-injured subjects. Non-recovery was only encountered in whiplash injury. Eleven non-recovered whiplash patients (defined as: handicap after 1 year) showed reduced time to peak pain from 1 week to 3 months (P<0.001), 6 months (P<0.01), but not 12 months after the injury. A larger pain area was seen in non-recovered vs. recovered whiplash-injured subjects during the entire observation period (P<0.001). Non-recovery after whiplash was associated with initially reduced cold pressor pain endurance and increased peak pain, suggesting that dysfunction of central pain modulating control systems plays a role in chronic pain after acute whiplash injury.
Kasch
Helge
H
Department of Neurology, Danish Pain Research Center, Aarhus University Hospital, Building 1A, Noerrebrogade 44, DK-8000 Aarhus, Denmark. helge.kasch@dadlnet.dk
Qerama
Erisela
E
Bach
Flemming Winther
FW
Jensen
Troels Staehelin
TS
D000063:Accidents, Traffic; D000293:Adolescent; D000328:Adult; D000368:Aged; D002490:Central Nervous System / Q000503:physiopathology; D002908:Chronic Disease / Q000523:psychology; D003080:Cold Temperature / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000209:etiology* / Q000503:physiopathology*; D059408:Pain Management; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D026741:Physical Therapy Modalities / Q000706:statistics & numerical data; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology; D013995:Time; D014911:Whiplash Injuries / Q000150:complications* / Q000503:physiopathology*