Researchers at the University of Eastern Finland and Kuopio University Hospital have developed a wearable device that can measure the occurrence and severity of myoclonic jerks, which are sudden muscle movements experienced by patients with progressive myoclonic epilepsy.
The method used in the study was based on the measurement of electrical neuromuscular function and movement, and it corresponded well to an assessment performed by an experienced physician. The findings were recently published in Clinical Neurophysiology.
Patients with progressive myoclonic epilepsy (EPM1) suffer from myoclonus, i.e., sudden muscle jerks that are activated by movement and other stimuli. The severity of these myoclonic jerks varies during the day, and myoclonus can be either positive or negative. A positive myoclonus refers to a sudden contraction of a muscle, while negative myoclonus refers to loss of muscle activation, which in a worst-case scenario may lead to the fall of a patient, for example.
The aim of this study was to develop and test a wearable technology-based method for assessing myoclonus symptoms in the home environment. Patients wore a small, wearable sensor on their arms for 48 hours, which measured their muscle function and movement. They also wrote down their own assessment of the severity of the myoclonus symptom. An algorithm that picks up the occurrence and variation of muscle jerks from the measurement data was developed to evaluate myoclonus symptoms, describing them as a myoclonus index, reports the University of Eastern Finland.
In current clinical practice, the Unified Myoclonus Rating Scale, UMRS, is used to assess myoclonus symptoms. When using the UMRS, an experienced physician views a video recording and scores the patient’s symptoms according to their severity. This UMRS assessment provides information on the occurrence of myoclonus at one point in time. The measurement-based myoclonus index developed in the study correlated well with the UMRS assessment performed by the physician. Patients’ at-home measurements showed that the measurement-based myoclonus index was able to detect variation in the occurrence of myoclonus symptoms during the day and night. The reliability of the measurement results was also supported by patients’ own, at-home assessments and reporting of their myoclonus symptoms.
According to the study, the myoclonus index can be used to reliably assess positive and negative myoclonus in patients with EPM1. This assessment correlates well with the assessment performed by an experienced physician, and also makes it possible to assess patients’ symptoms in the home environment.
The study was carried out as part of the larger New Modalities ecosystem funded by Business Finland, involving three universities and eight companies in Finland. The ecosystem is coordinated by Orion Corporation.