Sensory Profiles in Patients with Low Back Pain with and Without Radiculopathy.

OBJECTIVE: During routine clinical evaluation, it can be challenging to differentiate between lumbar radiculopathy (RAD) and lower back pain with non-radicular somatic referred pain (SRP) or even axial non-radiating low back pain (LBP). The aim of this study was to characterize patients with RAD, axial LBP (aLBP), and SRP on the basis of somatosensory profiles. METHODS: Patients with LBP (n = 54) were assessed with quantitative sensory testing in the area of LBP and, in cases of RAD, additionally in the area of projecting pain. Questionnaires (PainDETECT®, EuroQol-5D, Medical Outcomes Study Sleep Scale, Hannover Functional Ability Questionnaire for Back Pain, Roland Morris Disability Questionnaire, Short Form-12 Health Survey, and Hospital Anxiety and Depression Scale) were answered by all patients. RESULTS: Patients with RAD (n = 12) had higher pain intensity scores (numeric rating scale: 5.7 ± 1.5 vs 4.1 ± 2.2; P < 0.05) and higher PainDETECT scores (14.6 ± 6.13 vs 9.7 ± 6.2; P < 0.05) than did patients with aLBP and SRP (n = 42). Patients with RAD had a more pronounced loss of small-fiber function, increased mechanical hyperalgesia, and a trend toward increased sensitivity to thermal pain in the area of LBP compared with patients with aLBP and SRP. Within patients with RAD, sensory profiles of the area of projecting pain and the area of LBP did not differ. Pressure pain hyperalgesia (measured by pressure pain threshold) and loss of mechanical detection (measured by mechanical detection threshold) in combination with the PainDETECT items numbness and prickling reached the best predictive value in detecting a radiculopathy. CONCLUSIONS: Patients with RAD demonstrated more somatosensory abnormalities than did patients with aLBP and SRP, including increased mechanical hyperalgesia and a loss of mechanical detection. The combination of pressure pain threshold, mechanical detection threshold, numbness, and prickling in the area of LBP can be a time-efficient tool to identify patients with RAD.

Sensory symptoms in low back pain-how do they matter?

OBJECTIVE: Successful treatment of chronic low back pain (LBP) is difficult in clinical practice and hard to measure in trials. One reason might be the use of insufficient outcome parameters. The aim was to investigate the importance of typical clinical characteristics of chronic LBP on QoL and functionality. METHODS: A total of 51 patients with chronic LBP (19 with, 32 without radiculopathy) were investigated with different questionnaires. RESULTS: Burdening symptoms differed in frequency, intensity and impairment of QoL and functionality between patients with and without radiculopathy and between the area of pain within the same patient, i.e. between back and leg. Symptoms of nerve affection such as prickling pain and numbness were rated higher in the area of radiating pain than on the back in radiculopathy, and typical neuropathic pain symptoms such as burning pain, prickling, spontaneous pain, and feeling of deep pressure and pain at the beginning of movement were rated with a higher impairment of QoL and functionality in patients with compared to those without radiculopathy. Furthermore, intensity, impairment of QoL, and functionality were not necessarily reported in association with one another: some patients were highly impaired in QoL or functionality, despite a moderate-to-low pain intensity, whereas others suffered from severe pain, but were less impaired in QoL or functionality. CONCLUSION: Results suggest the consideration of impairment of QoL and functionality in addition to symptom intensity for treatment evaluation of chronic LBP. This can help to improve overall well-being of the patients and enhance efficacy in clinical pain trials and patient-centered treatment.