Postural disorders in Parkinson's disease and their response to interventions

Abstract

Introduction. Postural disorders are typical in Parkinson's disease (PD) and are increasing with progression of the disease. Although many studies concentrate on posture and gait, postural alignment is seldom studied. Aim of the study. The aim of this study was to investigate the reliability of a standardized postural rating tool and to examine the immediate and long-term effects of medication and deep brain stimulation (DBS) in the subthalamic nucleus on postural alignment in PD. Materials and methods. Two independent raters assessed three angles: total camptocormia (TCC), upper camptocormia (UCC) and Pisa angle of 192 PD patients and 78 HC with the free downloadable NeuroPostureApp. The photos of PD patients were made before and after the DBS surgery. The patients were tested with and without medication pre-surgical and retested post-surgical (6–24 months) in all treatment combinations of medication and DBS regarding the on and off conditions. Three subgroups were defined according to normative values of healthy controls and according to clinical criteria: patients with normal posture, with stooped posture, and with postural disorders. Results. For the interrater reliability, intra-class coefficients (ICCs) were 0.95 (95% CI: 0.94- 0.95), 0.83 (95% CI: 0.80-0.84) and 0.71 (95%CI: 0.67-0.74) for the TCC angle, UCC angle and Pisa angle assessment, respectively. This indicates excellent interrater reliability for the TCC angle, good reliability for the UCC angle and moderate reliability for the Pisa angle assessment. In 82 % of patients a stooped posture was observed with respect to the TCC angle and in 54 % with respect to the UCC angle, 62% had an abnormal Pisa angle. Camptocormia was diagnosed in ∼7% and a Pisa syndrome in 1% of the patients. Medication and DBS both significantly improved postural alignment in the entire cohort. Conclusions. The non-commercial NeuroPosturApp© assessed is a reliable and easy to handle tool for measuring postural alignment in healthy subjects and people with PD. The App proved to be capable of describing the total and upper camptocormia angles, and the Pisa angle. Both medication and stimulation improved postural alignment in anteroposterior and mediolateral direction in PD.