02/2020 – 06/2020
Dizziness, the general term for impairments in spatial perception and stability, is one of the most common complaints presented to doctors . About 20-30% of the general population is affected by subtypes of dizziness, e.g. vertigo and lightheadedness, with even increasing prevalence in the elderly population . The causes are manifold: They can range from a sudden drop in blood pressure or dehydration over disturbances of the vestibular organs (such as Benign paroxysmal positional vertigo or Ménière’s disease), to psychic diseases or stroke .
Vertigo can also be an early marker for disorders of the autonomic nervous system (ANS), such as Parkinson’s Disease (PD). It does not only affect the motor system, but also causes autonomic failures in blood pressure and heart rate regulation, especially in response to posture changes (also referred to as orthostatic dysregulation) . For that reason, it is important to detect vertigo and its reasons as early as possible in order to slow down disease progression in the best possible way . A common clinical procedure for assessing the cardiovascular response to posture changes is the “Schellong test”, where patients initially remain in a resting phase while lying down before they are instructed to stand up and remain in an upright position. During the test, heart rate and blood pressure are assessed .
However, the test is typically performed in clinical settings and can therefore be influenced by the “white-coat syndrome”, a phenomenon in which people experience elevated blood pressure and heart rate in a clinical setting, possibly due to anxiety . Hence, the patients’ physiology should be analyzed in a familiar environment and without creating the feeling of actually being monitored. By continuously measuring the patients’ reactions to posture changes in free-living environments, more data can be collected, and, possibly, more meaningful results can be obtained . However, this approach has not been well analyzed yet.
The goal of this bachelor’s thesis is therefore to assess whether the measurement of orthostatic reactions in a home monitoring setting is feasible. This goal will be achieved by comparing supervised orthostatic reactions in a clinical setting with supervised and unsupervised orthostatic reactions free-living environments . In order to detect postural changes and to select only events that are suitable for the evaluation of the orthostatic response, algorithms developed in previous works are applied [7, 9].
- Herbert L. Muncie Jr, Susan M. Sirmans, and Ernest James. “Dizziness: approach to evaluation and management.” American family physician 3 (2017): 154-162.
- Yuri Agrawal, et al. “Disorders of balance and vestibular function in US adults: data from the National Health and Nutrition Examination Survey, 2001-2004.” Archives of internal medicine 10 (2009): 938-944.
- E. Mihci, et al. “Orthostatic heart rate variability analysis in idiopathic Parkinson’s disease.” Acta neurologica scandinavica 5 (2006): 288-293.
- T. H. Haapaniemi, et al. “Ambulatory ECG and analysis of heart rate variability in Parkinson’s disease.” Journal of neurology, neurosurgery & psychiatry 70.3 (2001): 305-310.
- Alessandra Fanciulli, Nicole Campese, and Gregor K. Wenning. “The Schellong test: detecting orthostatic blood pressure and heart rate changes in German-speaking countries.” (2019): 1-4.
- Patrick Owen, Neil Atkins, and Eoin O’Brien. “Diagnosis of white coat hypertension by ambulatory blood pressure monitoring.” Hypertension 2 (1999): 267-272.
- Robert Richer, Benjamin H. Groh, Peter Blank, Eva Dorschky, Christine Martindale, Jochen Klucken, Bjoern M. Eskofier. “Unobtrusive real-time heart rate variability analysis for the detection of orthostatic dysregulation.” 2016 IEEE 13th International Conference on Wearable and Implantable Body Sensor Networks (BSN). IEEE, 2016.
- David G. Benditt, et al. “Tilt table testing for assessing syncope.” Journal of the American College of Cardiology1 (1996): 263-275.
- Daniel Krauß. “Heart Rate Variability Analysis for Unsupervised Tilt Table Testing during Daily-life Activities.” Bachelor’s Thesis, FAU (2019)