Central pain modulation and cognitive functioning in patients with traumatic and non-traumatic chronic neck pain: preliminary results

Background: Scientific research demonstrates the presence of central sensitization (CS) and cognitive deficits in patients with chronic whiplash associated disorders (CWAD). However, the underlying mechanisms are still unclear. To date, research regarding central pain modulation and cognitive performance in chronic non-traumatic neck pain patients is lacking. Aims: To examine central pain modulation and cognitive functioning in patients with CWAD and chronic idiopathic neck pain (CINP) compared to healthy individuals. Methods: Eighty-eight women (28 CWAD, 33 CINP and 27 pain-free controls), matched for age, were subjected to cognitive assessments and pain measurements. First, participants completed the modified Perceived Deficits Questionnaire (mPDQ). Subsequently, they performed the Trail Making Test (TMT). Afterwards, pressure pain thresholds (PPTs), and conditioned pain modulation (CPM) were evaluated. Results: Decreased PPTs were shown at the m. Trapezius, m. Quadriceps and lumbar region in CWAD (p<0.01) and at the m. Trapezius in CINP (p=0.009), compared to healthy women. PPTs increased significantly during the cold pressor test in the CINP (p<0.001) and control group (p<0.001). However, in the CWAD group, PPTs at the quadriceps remained the same during this CPM paradigm (p>0.05) and only the PPTs at the m. Trapezius slightly increased during the cold pressor test (p<0.01). CWAD patients displayed diminished psychomotor speed (TMT A) and decreased task-switching performance (TMT B) compared to CINP and controls (p<0.05). Further, both CINP and CWAD reported more self-perceived cognitive deficits (mPDQ) compared to controls (p<0.01). Conclusions: Primary hyperalgesia was demonstrated in traumatic and non-traumatic neck pain patients. However, secondary hyperalgesia and decreased CPM efficacy was shown in CWAD but not in CINP, which is indicative for the presence of CS in CWAD patients. Additionally, the results provide preliminary evidence for cognitive deficits in CWAD and to a lesser extent in CINP patients.

Publication year:2015