Does Conservative Treatment Change the Brain in Patients with Chronic Musculoskeletal Pain? A Systematic Review.
Chronic musculoskeletal pain is characterized by maladaptive central neuroplastic changes. Many observational studies have demonstrated that chronic pain states are associated with brain alterations regarding structure and/or function. Rehabilitation of patients with chronic musculoskeletal pain may include cognitive, exercise, or multimodal therapies.



The current review aims to provide a constructive overview of the existing literature reporting neural correlates, based on brain magnetic resonance imaging (MRI) techniques, following conservative treatment in chronic musculoskeletal pain patients.



Systematic review of the literature.



University medical centers in Belgium.



The current review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Literature was searched from 3 databases and screened for eligibility. Methodological quality across studies was assessed with Cochrane Collaboration's tool for assessing risk of bias and quality of evidence was determined applying the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.



A total of 9 eligible studies were identified with a predominant high risk of bias. Cognitive behavioral therapy induced several structural and functional changes predominantly in prefrontal cortical regions and a shift from affective to sensory-discriminative brain activity after behavioral extinction training. Multidisciplinary treatment in pediatric complex regional pain syndrome facilitated normalization of functional connectivity of resting-state networks and the amygdala, and increased gray matter in prefrontal and specific subcortical areas. Exercise therapy led to specific for resting-state functional connectivity and a trend towards pressure-induced brain activity changes.



A very small number of studies was available, which furthermore exhibited small study samples. Moreover, only 2 of the included studies were randomized controlled trials.



It is likely that conservative treatments may induce mainly functional and structural brain changes in prefrontal regions in patients with chronic musculoskeletal pain. Due to the relatively high risk of bias across the included studies, future studies with randomized designs are needed to confirm the current findings. In addition, more research evaluating the treatment-induced effects on white matter and whole-brain network dynamics are warranted.Key words: Chronic pain, musculoskeletal pain, MRI, functional MRI, therapy, rehabilitation, cognitive behavioral therapy, exercise therapy.
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University; Department of Physiotherapy, Physiology and Anatomy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel.
Jeroen
J
Kregel
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University.
Iris
I
Coppieters
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
Robby
R
DePauw
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium; Department of Physiotherapy, Physiology and Anatomy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; "Pain in Motion" international research group, www.paininmotion.be.
Anneleen
A
Malfliet
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
Lieven
L
Danneels
Pain in Motion Research Group (www.paininmotion.be); Department of Human Physiology and Physiotherapy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; Department of Physical Medicine and Physiotherapy, University Hospital Brussels, Brussels, Belgium.
Jo
J
Nijs
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
Barbara
B
Cagnie
Pain in Motion Research Group (www.paininmotion.be); Rehabilitation Sciences and Physiotherapy, Faculty of Medicine & Health Sciences, Ghent University, Ghent, Belgium; Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine & Health Sciences, University of Antwerp, Antwerp, Belgium.
Mira
M
Meeus
D015982:Bias; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D059350:Chronic Pain / Q000628:therapy*; D015928:Cognitive Behavioral Therapy; D003131:Combined Modality Therapy; D000072700:Conservative Treatment; D005081:Exercise Therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D059352:Musculoskeletal Pain / Q000628:therapy*