J Korean Med Sci.  2007 Dec;22(6):1002-1006. 10.3346/jkms.2007.22.6.1002.

The Correlation between F-wave Motor Unit Number Estimation (F-MUNE) and Functional Recovery in Stroke Patients

• Choi IS
• Kim JH
• Han JY
• Lee SG

• KMID: 1785761
• DOI: http://doi.org/10.3346/jkms.2007.22.6.1002

Abstract

The aim of this study was to follow up the changes in the number of motor units according to the Brunnstrom stage through a motor unit number estimation of the Fwave (F-MUNE) after a stroke, and to identify the functional significance of F-MUNE. Twenty-five patients (15 men, 10 women) with a first unilateral stroke were recruited. The maximal M-potential was evoked by the supramaximal stimulation of the median nerve at the wrist, and the maximal stimulation intensity was determined on both hemiplegic and unaffected hands. The reproducible all-or-none F-wave was evoked in 30% of the maximal stimulation intensity and was constantly stimulated at that level. The prototypes of the F-wave were chosen, and the values of F-MUNE were calculated by dividing the amplitude of the maximal M-potential by the mean amplitude of the F-prototype. The changes in F-MUNE were compared according to the progression of the Brunnstrom stage and correlated with those of the functional scales. The mean motor unit numbers decreased significantly in the hemiplegic side compared with the unaffected side. According to the progression of the Brunnstrom stage, the values of F-MUNE were reduced significantly by increasing the amplitude and recruitment of the F-prototype, and the functional scores also improved. These results show that the F-MUNE equation did not show a functional recoveryrelated increase in stroke patients.

Keyword

Stroke; Recovery of Function; Outcome Assessment; Neural Conduction

MeSH Terms

Aged
Female
Humans
Male
Middle Aged
Motor Neurons/*physiology
Prospective Studies
*Recovery of Function
Stroke/*physiopathology

Figure

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  Fig. 1 The prototypes of the F-wave, identically matched two or more F-waves with the same latency, amplitude, and shape were selected among the entire products of individual F-waves.

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  Fig. 2 The peak amplitude of the maximal M-potential (MMP) in the hemiplegic side was significantly smaller than in the unaffected side (p=0.000, between groups), but there was no significant changes according to the progression of the Brünnstrom stage on both sides (p>0.05, within groups). Repetitive measure analysis was used to examine the significance of the serial changes in the MMP according to the progression of the Brünnstrom stage.

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  Fig. 3 The functional scores by the functional independence measure (FIM) and modified Barthel index (MBI) were significantly improved according to the progression of the Brünnstrom stage (p= 0.000, repetitive measure analysis).

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  Fig. 4 The frequency of the F-prototypes was increased progressively and estimation of the number of motor units showing the F-wave (F-MUNE) decreased significantly according to the progression of the Brünnstrom stage (p=0.000, repetitive measure analysis).

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