Bayesian statistical MUNE method

We have developed a new method of motor unit number estimation (MUNE) for assessing diseases such as amyotrophic lateral sclerosis (ALS). We used data from the whole stimulus–response curve and then performed a Bayesian statistical analysis. The Bayesian method uses mathematical equations that express the basic elements of motor unit activation after electrical stimulation and allows for the sources of variability and uncertainty in this formulation. The Bayesian MUNE method was used to determine the most probable number of motor units in 8 normal subjects, 49 ALS subjects, and 3 subjects with progressive lower motor neuron (LMN) weakness. In normals the number of motor units was calculated to be 75–85 in hand and 40–58 in foot muscles. In ALS subjects the number of motor units per muscle was less than in normal subjects. In 17 ALS subjects and 3 subjects with LMN weakness the median, ulnar, or peroneal nerve was studied on repeated occasions over an average of 189 days (range 63–1,071) and the number of motor units progressively declined, with a half‐life ranging from 62–834 days. The results of our MUNE technique were reproducible on replicate studies. A Bayesian statistical MUNE method is a new approach that can be used to study ALS patients serially for assessment and treatment trials. Muscle Nerve, 2007

[1]  A. Brix.  Bayesian Data Analysis, 2nd edn , 2005 .

[2]  D. J. Parry,et al.  The relationship between surface potentials and the number of active motor units , 1977, Journal of the Neurological Sciences.

[3]  Daniel W. Stashuk,et al.  MUNE using decomposition-enhanced spike-triggered averaging , 2003 .

[4]  D. Burke,et al.  Multiple measures of axonal excitability: A new approach in clinical testing , 2000, Muscle & nerve.

[5]  J R Daube,et al.  Estimating the Number of Motor Units in a Muscle , 1995, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[6]  W F Brown,et al.  Multiple point electrical stimulation of ulnar and median nerves. , 1976, Journal of neurology, neurosurgery, and psychiatry.

[7]  Jasper R Daube,et al.  Effect of changing data collection parameters on statistical motor unit number estimates , 2003, Muscle & nerve.

[8]  Anthony N Pettitt,et al.  Motor Unit Number Estimation—A Bayesian Approach , 2006, Biometrics.

[9]  K J Felice,et al.  Thenar motor unit number estimates using the multiple point stimulation technique: Reproducibility studies in als patients and normal subjects , 1995, Muscle & nerve.

[10]  M. Swash,et al.  El Escorial revisited: Revised criteria for the diagnosis of amyotrophic lateral sclerosis , 2000, Amyotrophic lateral sclerosis and other motor neuron disorders : official publication of the World Federation of Neurology, Research Group on Motor Neuron Diseases.

[11]  A. Al-Chalabi,et al.  Flail arm syndrome: a distinctive variant of amyotrophic lateral sclerosis , 1998, Journal of neurology, neurosurgery, and psychiatry.

[12]  J F Yang,et al.  Methods for estimating the number of motor units in human muscles , 1990, Annals of neurology.

[13]  Hugh Bostock,et al.  Variations in excitability of single human motor axons, related to stochastic properties of nodal sodium channels , 2004, The Journal of physiology.

[14]  D. Stegeman,et al.  Statistical motor unit number estimation assuming a binomial distribution , 2005 .

[15]  A N Pettitt,et al.  The stimulus–response curve and motor unit variability in normal subjects and subjects with amyotrophic lateral sclerosis , 2006, Muscle & nerve.

[16]  Cecil Hershler,et al.  Motor unit estimates obtained using the new “MUESA” method , 1996, Muscle & nerve.

[17]  D. Schoenfeld,et al.  The use of statistical MUNE in a multicenter clinical trial , 2004, Muscle & nerve.

[18]  M J Campbell,et al.  Electrophysiological estimation of the number of motor units within a human muscle , 1971, Journal of neurology, neurosurgery, and psychiatry.

[19]  J. Daube,et al.  Decrement in surface-recorded motor unit potentials in amyotrophic lateral sclerosis , 2004, Neurology.

[20]  P. Andersen,et al.  Flail arm syndrome: a clinical variant of amyotrophic lateral sclerosis , 2004, European journal of neurology.

[21]  D. Burke,et al.  Excitability of human axons , 2001, Clinical Neurophysiology.

[22]  D. Schoenfeld,et al.  Revised statistical motor unit number estimation in the Celecoxib/ALS trial , 2007, Muscle & nerve.

[23]  P. Green.  Reversible jump Markov chain Monte Carlo computation and Bayesian model determination , 1995 .

[24]  Daniel W Stashuk,et al.  Motor unit number estimation by decomposition‐enhanced spike‐triggered averaging: Control data, test–retest reliability, and contractile level effects , 2004, Muscle & nerve.

[25]  Anthony N. Pettitt,et al.  Motor unit number estimation using reversible jump Markov chain Monte Carlo methods , 2007 .

[26]  M. Brandstater,et al.  Motor unit number estimate–based rates of progression of ALS predict patient survival , 1999, Muscle & nerve.

[27]  J. Shefner,et al.  Single motor unit variability with threshold stimulation in patients with amyotrophic lateral sclerosis and normal subjects , 2004, Muscle & nerve.

[28]  Jeremy M. Shefner,et al.  Motor unit number estimation in human neurological diseases and animal models , 2001, Clinical Neurophysiology.

[29]  T J Doherty,et al.  A method for the longitudinal study of human thenar motor units , 1994, Muscle & nerve.