Context
Pain is a poorly managed aspect in fibrous dysplasia/McCune-Albright Syndrome (FD/MAS) due to uncertainties regarding the clinical, behavioral, and neurobiological underpinnings that contribute to pain in these patients.
Objective
Identify neuropsychological and neurobiological factors associated pain severity in FD/MAS.
Design
Prospective, single-site study
Patients
20 FD/MAS patients and 16 age-sex matched healthy controls (HCs)
Intervention
Assessments of pain severity, neuropathic pain, pain catastrophizing (pain rumination, magnification, and helplessness), emotional health, and pain sensitivity with thermal quantitative sensory testing [QST]). Central nervous system (CNS) properties were measured with diffusion tensor imaging, structural magnetic resonance imaging, and functional MRI.
Main outcome measures
Questionnaire responses, detection thresholds and tolerances to thermal stimuli, and structural and functional CNS properties.
Results
Pain severity in FD/MAS patients was associated with more neuropathic pain quality, and higher levels of pain catastrophizing, and depression. QST revealed normal detection of non-noxious stimuli in patients. Individual with FD/MAS had higher pain tolerances relative to HCs. From neuroimaging studies, greater pain severity, neuropathic pain quality, and psychological status of the patient were associated with reduced structural integrity of white matter pathways (superior thalamic radiation and uncinate fasciculus), reduced gray matter thickness (pre-/paracentral gyri), and heightened responses to pain (precentral, temporal, and frontal gyri). Thus, properties of CNS circuits involved in processing sensorimotor and emotional aspects of pain were altered in FD/MAS.
Conclusions
These results offer insights into pain mechanisms in FD/MAS, while providing a basis for implementation of comprehensive pain management treatment approaches that addresses neuropsychological aspects of pain.