Research article

BMC Neurology

, 12:98

Open Access This content is freely available online to anyone, anywhere at any time.

Enhanced sensitivity to punctate painful stimuli in female patients with chronic low back pain

  • Christian PutaAffiliated withDepartment of Sports Medicine and Health Promotion, Friedrich Schiller UniversityCenter for Interdisciplinary Prevention of Diseases related to Professional Activities, Friedrich Schiller University Email author 
  • , Birgit SchulzAffiliated withDepartment of Sports Medicine and Health Promotion, Friedrich Schiller University
  • , Saskia SchoelerAffiliated withDepartment of Biological and Clinical Psychology, Friedrich Schiller University
  • , Walter MagerlAffiliated withDepartment of Neurophysiology, Center for Biomedicine and Medical Technology Mannheim (CBTM), Ruprecht Karls University Heidelberg
  • , Brunhild GabrielAffiliated withDepartment of Sports Medicine and Health Promotion, Friedrich Schiller UniversityDepartment of Biological and Clinical Psychology, Friedrich Schiller University
  • , Holger H W GabrielAffiliated withDepartment of Sports Medicine and Health Promotion, Friedrich Schiller University
  • , Wolfgang H R MiltnerAffiliated withDepartment of Biological and Clinical Psychology, Friedrich Schiller University
  • , Thomas WeissAffiliated withDepartment of Biological and Clinical Psychology, Friedrich Schiller University

Abstract

Background

Chronic low back pain (CLBP) has been shown to be associated with various pathophysiological changes at several level of the sensorimotor system, pointing to a general hypersensitivity in CLBP patients. The aim of the present study was to investigate signs of generalized mechanical pain hypersensitivity in CLBP patients on the hand and on the painful site of the back.

Methods

Pinprick stimulation according to a validated standardized quantitative sensory testing protocol was used in 14 female CLBP patients and 14 healthy controls (HC) matched for sex and age. Stimulus response functions to pinprick stimulation on the skin were examined at the affected back and reference sites (hand palmar and hand dorsum). Data from CLBP patients were compared with HC and with reference data from the German Research Network on Neuropathic Pain.

Results

We found significant differences in the stimulus response functions between CLBP patients and HC. Pain ratings to the pinpricks were increased for low and moderate pinprick stimuli in CLBP patients. Importantly, this kind of specific pinprick hyperalgesia was found not only for the affected body site (back), but also for the remote reference sites (hand dorsum and hand palmar).

Conclusions

We interpret our results as pointing to changes in the nociceptive processing in CLBP at higher levels of the neuraxis, possibly thalamus and/or attentional control, rather than changes of spinal processing. Alternatively, there might be a higher vulnerability to noxious stimulation in CLBP patients.

Keywords

Chronic Low Back Pain (CLBP) Mechanical pain thresholds Pinprick hyperalgesia Allodynia