The relation between the single fiber electromyography parameters and the prognosis of motor neuron disease

Abstract EN

Hypothesis : single fiber electromyography (SFEMG) can be an adjunct to routine EMG studies in revealing information about the continuous process of denervation and enervation occurring in motor neuron disease (MND).

Increased jitter, blocking percentage and fiber density (FD) can indicate the degree of immature collateral sprouts and motor end plates resulting from the progressive denervation and enervation associated with MND, and may be helpful in evaluating prognosis.

Methodology : Twenty patients suffering of MND had undergone SFEMG from the extensor digitroum communist (EDC) and the obtained SFEMG parameters (mean jitter, fiber density and blocking percentage) had been compared with control group and were correlated with other predictive factors of prognosis including the EDC strength, the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS), the Amyotrophic Lateral Sclerosis Severity Score (ALSSS) as well as to other assumed measures for the severity of MND including the duration of the MND and the spontaneous activity detected with EMG studies.

Results : A statistically significant difference was found between the patients and control group and statistically significant correlations had existed between the SFEMG parameters with different predictive prognostic measures.

It was concluded that the jitter and blocking percentage are predictive factors for bad prognosis, while fiber density is a predictive factor for good prognosis in MND.

Moreover, all the SFEMG parameters had proven to be of significant diagnostic value in MND.

Recommendation : The use the SFEMG parameters in the diagnosis and prediction of the prognosis of MND.