Decreased central fatigue in multiple sclerosis patients after 8 weeks of surface functional electrical stimulation

Abstract

Abstract-Effective treatments for multiple sclerosis (MS)-associated central fatigue have not been established. Surface functional electrical stimulation (FES), which can challenge the peripheral neuromuscular system without overloading the central nervous system, is a relatively safe therapeutic strategy. We investigated the effect of 8 weeks of surface FES training on the levels of general, central, and peripheral fatigue in MS patients. Seven of nine individuals with MS (average age: 42.86 +/-13.47 years) completed 8 weeks of quadriceps muscle surface FES training. Maximal voluntary contraction, voluntary activation level, twitch force, General Fatigue Index (FI), Central Fatigue Index (CFI), Peripheral Fatigue Index, and Modified Fatigue Impact Scale (MFIS) scores were determined before and after training. The results showed that FI (p = 0.01), CFI (p = 0.02), and MFIS (p = 0.02) scores improved significantly after training. Improvements in central fatigue contributed significantly to improvements in general fatigue (p < 0.01). The results of the current study showed that central fatigue was a primary limitation in patients with MS during voluntary exercise and that 8 weeks of surface FES training for individuals with MS led to significantly reduced fatigue, particularly central fatigue.

Fatigue and Muscle Strength Involving Walking Speed in Parkinson’s Disease: Insights for Developing Rehabilitation Strategy for PD

“…The subjects were seated on a custom-made knee extension force measurement system, which included a force transducer (AWU, Genisco Technology, CA, USA) coupled to a transducer amplifier (Gould Inc., Valley View, OH, USA), to measure the knee isometric extension force at 90 degrees of flexion [14]. Responses were sampled at 1000 Hz and recorded on a computer using a Power 1401 laboratory interface (Cambridge Electronic Design, Cambridge, UK) for offline analysis.…”

“…VA was measured using the interpolated twitch test [14, 19]. During the test, the quadriceps muscle was stimulated (Digitimer DS7A, Digitimer Ltd., Welwyn Court, UK) with surface electrodes.…”

“…By calculating the change in VA caused by exercise, exercise-induced central fatigue can be quantified. The peripheral fatigue index (PFI) was calculated as the ratio of the postfatigue twitch force to the prefatigue twitch force [14, 15]. The GFI, CFI, and PFI had values between 0 and 1, with a higher value indicating less general fatigue, central fatigue, and peripheral fatigue, respectively.…”

“…It has been shown that fatigue in patients with CNS disorders such as multiple sclerosis involve both central and peripheral components. Central fatigue may include mental fatigue and a decrease in motivation [14, 15]. In contrast, peripheral fatigue may result from neuromuscular transmission failure along α motor neurons, neuromuscular junctions, muscle cell membranes, and factors within muscle fibers such as E-C coupling failure [16].…”

The effects of whole-body vibration (WBV) intervention on body functions, activity limitations, and participation restrictions in people with neurological conditions

“…Reductions in muscle activity in people with neurological conditions may be due to both peripheral and central mechanisms. For instance, in MS, Chang et al 46 suggest that central nervous system factors were a greater factor in reduced muscle fatigue than peripheral elements; the same may be true of muscle power. Therefore, if the mechanism of WBV is to stimulate muscle spindle (i.e., peripheral elements), it may not be effective in changing central processes necessary for increased muscle contraction.…”