A Longitudinal Clinical Study of Neurophysiological Responses and Patient-reported Outcomes throughout a Programme of Physiotherapy for Acute & Sub-acute Low Back Pain.

Study Design
A pragmatic, prospective, longitudinal, observational study recording sympathetic nervous system (SNS) skin conductance (SC) responses and patient reported outcome measure (PROM) changes to a program of guideline-endorsed physiotherapy treatment for low back pain (NSLBP) symptoms of up to 12 weeks duration.
Objectives
To record SC changes within- and between-treatment episodes at treatment inception, mid-point and discharge and observe correlations between the magnitude of SC responses, pain abatement (narrative pain rating scale - NPRS) and functional restoration (Oswestry Disability Index - ODI).
Background
Despite guideline recommendations for the use of manual and exercise therapies for the early management of LBP, there is little empirical clinical evidence to support the long-term neurophysiological effects of therapy in this clinical group.
Methods
Sixty patients received a guideline-endorsed physiotherapy treatment programme. Continuous neurophysiological recordings of SC activity levels were taken throughout each treatment. PROM data were extracted from inception, mid-point and discharge. Within- and between-treatment analyses determined the nature of SC changes and correlations to longitudinal changes in pain and function.
Results
SC changes were significant during all ‘treatment’ periods (p=0.044) with the greatest magnitude of sympatho-excitatory responses occurring at inception (219%). The treatment modality providing the maximum SNS response was a high velocity lumbar rotation manipulation. Positive correlations were identified between SC responses, ODI improvements (r=0.82, p<0.0005) and pain abatement (r=0.459, p<0.0005).
Conclusions
Patients with LBP exhibit neurophysiological treatment responses indicative of a symptom-related neuroplastic state of dorsal horn sensitisation that is receptive to early manual therapy intervention.