Fatigued patients with multiple sclerosis can be discriminated from healthy controls by the recordings of a newly developed measurement system (FAMOS): a pilot study

Abstract

Purpose: To explore the difference between fatigued patients with multiple sclerosis (MS) and matched healthy controls by applying a newly developed physiological and functional data recording system. Methods: A portable wireless measurement system, named FAtigue MOnitoring System (FAMOS), has been developed, which can continuously measure electrocardiogram (ECG), body skin temperature, electromyogram, and motion parameters. In a pilot study, 17 fatigued MS patients (fatigue severity scale (FSS) = 53.9 SD 5.4) and 9 healthy matched controls (FSS = 27.2 SD 6.8) were recruited and monitored by FAMOS during the execution of functional (36 m walk test, 5- and 50-repetition sit-to-stand test) and cognitive (short-term memory tests) tests. Furthermore, oxygen saturation (SPO₂) was measured during the functional and cognitive tests and during rest periods between these tests. Results: Recordings from FAMOS indicate that fatigued MS patients have reduced standard deviation (SD) of the heart rate (HR) during the short-term memory test, reduced high frequency (HF) component power spectrum (representing parasympathetic activation) at rest after walk test, and higher ratio of low frequency (LF) to HF (LF/HF) during 50-repetition sit-to-stand test. Conclusions: FAMOS recordings can discriminate fatigued MS patients from healthy controls. The data indicate that fatigued MS patients have vagus nerve dysfunction during cognitive tests and disturbed sympathovagal balance during stressful physical tests.

Implications for Rehabilitation

• Fatigue is reported as the most common symptom by patients with multiple sclerosis, but the mechanism of this symptom is still not clearly understood.

• Wireless body sensor networks is one of the most promising concepts for healthcare and rehabilitation providing long-term health monitoring of subjects under conditions without constraining the subjects’ normal daily activities, but such system has not been used in the study of fatigue in MS.

• The main findings of this pilot study were that FAMOS can discriminate fatigued MS patients from healthy controls, and recordings extracted from specific monitoring periods indicate autonomic dysfunction in MS patients characterized by primary fatigue.

Keywords::

• Autonomic dysfunction
• fatigue
• measure
• multiple sclerosis
• physiological and functional parameters

Acknowledgement

The authors would like to acknowledge the participants, who volunteered to take the test. Many thanks go to nurse Susanne Aabling for her help in contacting the patients. The authors also appreciate Dr. Massimo Mischi, Dr. Chiara Rabotti, and Mr. Micheal Rooijakkers for their comments and suggestions on the signal processing algorithms.

Declaration of interest

The authors report no declarations of interest.