Multiple sclerosis (MS) is an insidious disease. Patients suffer because their immune system is attacking their own nerve fibres, which inhibits the transmission of nerve signals. People with MS experience mild to severe impairment of their motor function and sensory perception in a variety of ways. These impairments disrupt their daily activities and reduce their overall quality of life. As individual as the symptoms and progression of the disease are, so too is the way it is managed. To monitor the disease progression and be able to recommend effective treatments, physicians ask their patients on a regular basis to describe their symptoms, such as fatigue.
Going off memory
Patients are thus faced with the tricky task of having to provide information about their state of health and what they have been capable of over the past few weeks and even months from memory. The data gathered in this way can be inaccurate and incomplete because patients might misremember details or tailor their responses to social expectations. And since these responses have a significant impact on how the progression of the disease is recorded, it could be mismanaged.
“Physicians would benefit from having access to reliable, frequent and long-term measurements of patients’ health parameters that give an accurate and comprehensive view of their state of health,” explains Shkurta Gashi. She is lead author of a new study and postdoc in the groups led by ETH Professors Christian Holz and Gunnar Rätsch at the Department of Computer Science as well as a fellow of the ETH AI Center.
Together with colleagues from ETH Zurich, the University Hospital Zurich, and the University of Zurich, Gashi has now shown that fitness trackers and smartphones can provide this kind of reliable long-term data with a high temporal resolution. Their study was published in the journal external pageNPJ Digital Medicinecall_made.
Digital markers for MS
The researchers recruited a group of volunteers – 55 with MS and a further 24 serving as control subjects – and provided each person with a fitness tracking armband. Over the course of two weeks, the researchers collected data from these wearable devices as well as from participants’ smartphones. They then performed statistical tests and a machine learning analysis of this data to identify reliable and clinically useful information.
What proved particularly meaningful was the data on physical activity and heart rate, which was collected from participants’ wearable devices. The higher the participants’ disease severity and fatigue levels, the lower their physical activity and heart rate variability proved to be. Compared to the controls, MS patients took fewer steps per day, engaged in an overall lower level of physical activity and registered more consistent intervals between heartbeats.
