Quantitative measurement of axial rigidity, functional status and health-related quality of life in patients with Parkinson's disease

Introduction. Rigidity is a cardinal symptom of Parkinson's disease (PD) Clinically, rigidity is usually assessed by passively flexing and extending a patient's limb Few studies have assessed rigidity in trunk muscles in PD patients Aims. To develop an objective measurement to quantify trunk rigidity in PD patients, and to examine its relationship with disease severity using the Hoehn and Yahr staging score (H&Y) and the Unified Parkinson's Disease Rating Scale III (UPDRS-III), disease duration, functional status with the Schwab 8 England activities of daily living scale and health related quality of life (HRQoL) was assessed with the European Quality of Life-5 Dimensions and Parkinson's Disease Questionnaire-39 items (PDQ-39) Patients and methods. An isokinetic dynamometer Biodex System 3 was employed to assess trunk rigidity in 36 PD patients Passive trunk flexion and extension at 3 angular velocities, 30 degrees/s, 45 degrees/s and 60 degrees/s were applied and resistive torques were recorded as trunk flexor and extensors rigidity Results. Significant correlations between trunk flexors-extensors tone and HEY staging score, UPDRS-III, disease duration and functional status at 30 degrees/s, 45 degrees/s and 60 degrees/s were obtained Trunk rigidity was correlated with the HRQoL assessed with the PDQ-39 Conclusions. Our results suggest that the 30 degrees/s, 45 degrees/s and 60 degrees/s angular velo cities of this objective method was valid to assess trunk rigidity and was correlated with disease severity, disease duration, functional status and HRQoL in PD patients