Physical activity and sedentary behaviour in people living with cervical dystonia

Abstract

Physical activity (PA) and sedentary behaviour (SB) have a significant impact on symptoms, disease progression, and quality of life of people having neurological disorders. Hence, measuring these behaviors and determining their impact on health helps PA-based treatment approaches to improve health and manage disease progression. Cervical dystonia (CD) is a neurological disorder having associated motor and non-motor symptoms, causing a significant impact on health and activity behaviours. This PhD assessed and described the PA and SB in CD using currently available best practice guidelines for device-based acquisition, extraction, and analysis of activity data. The project also aimed to explore the likelihood of PA resulting in aggravation of dystonia-related symptoms in this population. To begin making recommendations for future research regarding exercise prescription in CD, a systematic review was initially conducted to synthesize how accelerometer-based activity data is currently collected and processed and to summarize the associations between activity behaviours and health outcomes in neurological populations. Five databases were searched to include accelerometer-based studies in adults with idiopathic neurological conditions. Results showed that the most used accelerometers were the Actigraph (AG) and activPAL. There was high compliance (> 85%) to wear, but studies lacked consensus on best practice criteria for data processing. Some recommendations are still drawn based on the majority of studies in systematic review, including 10 hours of waking wear to validate day, 3 out of 7 consecutive days of valid wear for habitual activity measurement, sedentary behaviour was accurately measured using activPAL, while AG was more accurate measuring activity. Based on these recommendations the second and third part of the Ph.D. was designed. The second study validated the activPAL accelerometer against direct observation in CD for activities such as stepping and transitions. Results supported the preliminary findings on activPAL being valid in assessing these measures. For the third part, the cohort of participants then wore the activPAL for seven days for the measurement of their habitual activity behaviours, completed health-related questionnaires (for disease rating, sleep, anxiety, depression, fatigue, quality of life, behavioral regulation, and self-efficacy to exercise), and performed supervised functional assessments including grip strength and usual gait speed. Based on recommendations from systematic review, the device data was analysed using the best practice suggestions. Analysis of the seven-day activity data showed that although participants spent most of their waking time either sedentary or accumulating low-intensity activities, they were also accumulating the recommended levels of moderate-vigorous intensity activity per week through incidental activities and their functional measures were comparable to healthy adults. PA wasn't significantly associated with any health-related measures except exercise self-efficacy and behavioural regulation. SB exhibited no significant associations with any of the health outcomes measured. Finally, based on previous reports that people with CD experience an increase in the severity of their symptoms after performing high intensity exercise, the fourth study was designed that aimed to determine the exercise threshold for symptom aggravation after exercise. This final study in the PhD was a test-retest reliability study in which an exercise tolerance test was repeated a minimum of one week apart to see whether exercise resulted in a consistent change in symptoms. In this study, participants performed two bouts of submaximal exercise on a recumbent bike separated by a week and reported their dystonia-related symptom severity during and a week after the exercise bouts. According to the results, participants seemed to achieve a moderate-vigorous exercise intensity without significant symptom exacerbation, but the reliability of the test was poor, indicating variations in symptoms between two bouts. In short, this project has improved the knowledge base regarding a rare neurological disorder, cervical dystonia. It also highlighted the current physical activity and sedentary behaviour this population accumulates, their association with motor and non-motor symptoms, and the intensity of exercise that can be safely achieved without symptoms aggravation. Hence highlighting the role of physical activity as a holistic approach to managing cervical dystonia.