Characterizing Camptocormia in Parkinson's Disease Using Muscle Ultrasonography

Background: Camptocormia (CC) is the forward-bending of the spine of more than 30 degrees that can be found in Parkinson's disease (PD) as a disabling complication. Detection of changes in paraspinal lumbar musculature inCCis of value for choosing treatment strategies. Objective: To investigate whether these changes can be detected using muscle ultrasonography (mUSG). Methods: Age and sex-matched groups comprised 17 PD patients with CC (seven acute, PD-aCC; 10 chronic PD-cCC), 19 PDpatients with no CC, and 18 healthy controls (HC). Lumbar paravertebral muscles (LPM) on both sides were assessed using mUSG by two different raters blinded to the group assignment. Groups were compared with regard to the linear measurements of the muscle thickness as well as semi-quantitative and quantitative (grayscale) analyses of muscle echogenicity using a univariate general linear model. Results: All assessments showed substantial interrater reliability. The PD-cCC group had significantly thinnerLPMcompared to groups with no CC (PD and HC). Groups of PD-aCC and PD-cCC differed from the groups of no CC in quantitative and semi-quantitative analyses of LPM echogenicity, respectively. Conclusion: Assessment of LPM in PD patients with CC can be reliably performed using mUSG. Also, mUSG may be used as a screening tool to detect CC-related changes in thickness and echogenicity of the LPM in patients with PD.