Rights statement: The final, definitive version of this article has been published in the Journal, Clinical Neurophysiology 123 (12), 2012, © ELSEVIER.
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Use of Bayesian MUNE to show differing rate of loss of motor units in subgroups of ALS
AU - Baumann, Fusun
AU - Henderson, Rob
AU - Ridall, Gareth
AU - Pettitt, Anthony
AU - McCombe, Pam
N1 - The final, definitive version of this article has been published in the Journal, Clinical Neurophysiology 123 (12), 2012, © ELSEVIER.
PY - 2012/12
Y1 - 2012/12
N2 - ObjectivesTo evaluate differences among patients with different clinical features of ALS, we used our Bayesian method of motor unit number estimation (MUNE).MethodsWe performed serial MUNE studies on 42 subjects who fulfilled the diagnostic criteria for ALS during the course of their illness. Subjects were classified into three subgroups according to whether they had typical ALS (with upper and lower motor neurone signs) or had predominantly upper motor neurone weakness with only minor LMN signs, or predominantly lower motor neurone weakness with only minor UMN signs. In all subjects we calculated the half life of MUs, defined as the expected time for the number of MUs to halve, in one or more of the abductor digiti minimi (ADM), abductor pollicis brevis (APB) and extensor digitorum brevis (EDB) muscles.ResultsThe mean half life of MUs was less in subjects who had typical ALS with both upper and lower motor neurone signs than in those with predominantly upper motor neurone weakness or predominantly lower motor neurone weakness. In 18 subjects we analysed the estimated size of the MUs and demonstrated the appearance of large MUs in subjects with upper or lower motor neurone predominant weakness. We found that the appearance of large MUs was correlated with the half life of MUs.ConclusionsPatients with different clinical features of ALS have different rates of loss and different sizes of MUs.SignificanceThese findings could indicate differences in disease pathogenesis.
AB - ObjectivesTo evaluate differences among patients with different clinical features of ALS, we used our Bayesian method of motor unit number estimation (MUNE).MethodsWe performed serial MUNE studies on 42 subjects who fulfilled the diagnostic criteria for ALS during the course of their illness. Subjects were classified into three subgroups according to whether they had typical ALS (with upper and lower motor neurone signs) or had predominantly upper motor neurone weakness with only minor LMN signs, or predominantly lower motor neurone weakness with only minor UMN signs. In all subjects we calculated the half life of MUs, defined as the expected time for the number of MUs to halve, in one or more of the abductor digiti minimi (ADM), abductor pollicis brevis (APB) and extensor digitorum brevis (EDB) muscles.ResultsThe mean half life of MUs was less in subjects who had typical ALS with both upper and lower motor neurone signs than in those with predominantly upper motor neurone weakness or predominantly lower motor neurone weakness. In 18 subjects we analysed the estimated size of the MUs and demonstrated the appearance of large MUs in subjects with upper or lower motor neurone predominant weakness. We found that the appearance of large MUs was correlated with the half life of MUs.ConclusionsPatients with different clinical features of ALS have different rates of loss and different sizes of MUs.SignificanceThese findings could indicate differences in disease pathogenesis.
KW - ALS
KW - Exponential decay
KW - Motor unit
KW - MUNE
KW - Disease phenotypes
U2 - 10.1016/j.clinph.2012.04.022
DO - 10.1016/j.clinph.2012.04.022
M3 - Journal article
VL - 123
SP - 2446
EP - 2453
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
SN - 1388-2457
IS - 12
ER -