title: Ultrasound strain elastography in assessment of resting biceps brachii muscle stiffness in patients with Parkinson's disease: a primary observation.
abstract: The aim of this study was to evaluate the feasibility of ultrasound strain elastography (SE) for the assessment of resting biceps brachii muscle (BBM) stiffness in patients with Parkinson's diseases (PD). From May 2014 to December 2014, we prospectively performed SE of BBM in 14 patients with PD and 10 healthy controls. Based on the Unified Parkinson's Disease Rating Scale for scoring muscle rigidity (UPDRS, part III), muscle rigidity scores in 14 patients with PD included 3 patients with high rigidity (UPDRS III-IV) and 11 patients with low rigidity (UPDRS I-II). Ultrasound strain was represented by the deformation of the BBM and subcutaneous soft tissues that was produced by external compression with a sand bag (1.5 kg) tied onto an ultrasound transducer. Deformation was estimated with two-dimensional speckle tracking. The difference in strain ratio (SR, defined as mean BBM strain divided by mean subcutaneous soft tissue strain) between PD and healthy controls was tested by unpaired t test. The correlation between SR and muscle rigidity score was analyzed by Pearson correlation coefficient. The reliability of SR in assessment of BBM stiffness was tested using intraclass correlation coefficient. In our result, the SR in PD and healthy controls measured 2.65±0.36 and 3.30±0.27, respectively. A significant difference in SR was noted between the healthy controls and PD (P=.00011). A negative correlation was found between SR and UPDRS rigidity score (r=-0.78). Our study suggests that the SR of BBM to reference tissue can be used as a quantitative biomarker in assessing resting muscle stiffness associated with muscle rigidity in PD.
authors.affiliation: Department of Radiology,Weill Cornell Medical College,New York,NY,USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Ultrasound,Beijing Tiantan Hospital,Capital Medical University,Beijing,China.
authors.forename: Wen
authors.initials: W
authors.lastname: He
authors.affiliation: Department of Ultrasound,Beijing Tiantan Hospital,Capital Medical University,Beijing,China. Electronic address: dulijuantt@163.com.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Du
authors.affiliation: Department of Ultrasound,Beijing Tiantan Hospital,Capital Medical University,Beijing,China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Ultrasound,Beijing Tiantan Hospital,Capital Medical University,Beijing,China.
authors.forename: Ling-Gang
authors.initials: LG
authors.lastname: Cheng
authors.affiliation: Department of Radiology,Weill Cornell Medical College,New York,NY,USA.
authors.forename: George
authors.initials: G
authors.lastname: Shih
authors.affiliation: Department of Radiology,University Hospital Health System,Ann Arbor,MI,USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rubin
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm / Q000000981:diagnostic imaging* / Q000473:pathology; D015415:Biomarkers; D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009127:Muscle Rigidity / Q000000981:diagnostic imaging*; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000473:pathology; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D011446:Prospective Studies; D015203:Reproducibility of Results; D012146:Rest; D013314:Stress, Mechanical; D014463:Ultrasonography / Q000379:methods*
chemical_list: D015415:Biomarkers
keywords: Biceps brachii muscle; Muscle rigidity; Parkinson's disease; Speckle tracking; Ultrasound strain elastography