[Application of the motor unit number estimation (MUNE-Poisson) statistical technique in patients with neurogenic processes].
BACKGROUND
Little research has been conducted on applying the statistical estimation of the number of motor units (the MUNE statistic) in the diagnosis of neurogenic processes.


OBJECTIVE
To determine the sensitivity of this test in patients with different neurogenic processes and to disseminate and clarify its basic methodological aspects.


METHODS
Both the conventional calculation and the modified version of the MUNE-Poisson put forward by Shefner et al (MUNEm) were used to carry out unilateral studies of the extensor digitorum brevis muscle in 82 patients who had previously been clinically and electromyographically diagnosed with sensory-motor axonal polyneuropathy (36 cases), unilateral L5 radiculopathy (26 patients) and second motor neuron disease (20 cases).


RESULTS
Overall sensitivity of the two methods was 81.7% and 82.9%, respectively, with no significant differences between them. Similarly, the sensitivity of the MUNE studies does not differ statistically according to the diagnosis. Patients who had a compound muscle action potential (CMAP) with a reduced amplitude displayed significantly higher sensitivity in MUNE studies (94.8%) than those who exhibited a normal CMAP (69.7%) (p < 0.001).


CONCLUSIONS
Although routine use of the MUNE statistical method is unnecessary in daily practice, it should be considered for use in processes in which conventional muscle electromyography, especially involving distal ones, offers doubtful results or the aim is to follow the progression of certain neurogenic processes.
Servicio de Neurofisiología Clínica, Hospital Universitario Reina Sofía, 14004 Córdoba, España. ljimenezgonzalez@hotmail.com
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Murga-Oporto
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Jiménez-González
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Márquez-Báez
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Méndez-García
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Guerra-Puerta
D000200:Action Potentials / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D002648:Child; D003627:Data Interpretation, Statistical; D004576:Electromyography; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology*; D009468:Neuromuscular Diseases / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D016012:Poisson Distribution; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity