Quantitative methods for estimating the number of motor units in human muscles

Brown, William F.; Chan, K. Ming

doi:10.1002/(sici)1097-4598(1997)5+<70::aid-mus17>3.0.co;2-2

Cited by 7 publications

(4 citation statements)

References 14 publications

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“…44 Four methods have been developed. 53 Each has its own distinct difficulties, but there is reasonable agreement between them as to the estimate of the number of motor units that have been made in several different muscles. Three of the methods use nerve stimulation and recording of the compound muscle action potential (CMAP) [50][51][52] ; the fourth relies on voluntary EMG.…”

Section: Motor Unit Estimatesmentioning

confidence: 98%

“…The spike-triggered averaging method developed by Brown and Chan 53 involves voluntary activation of a single motor unit that is used to trigger a surfacerecorded "macro" potential of the same unit. Window discriminators, which are available on most current EMG equipment, make it possible to record the macro potential triggered by different-sized motor units that are recruited during moderate voluntary muscle contraction.…”

Section: Motor Unit Estimatesmentioning

confidence: 99%

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Clinical Electrophysiology of the Upper and Lower Motor Neuron in Amyotrophic Lateral Sclerosis

Eisen

2001

Semin Neurol

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Electrophysiology is important in amyotrophic lateral sclerosis (ALS). It helps in the assessment of disease severity and rate of progression, and it plays a role in evaluating the efficacy of therapeutic trials. Presently, electrophysiology is the only means of confirming suspected ALS, and this has been incorporated into the El Escorial criteria. Needle electromyography identifies disease in clinically "unaffected muscles" including bulbar musculature, confirms involvement of anterior horn cells, and can detect early involvement of respiratory muscles (intercostals and diaphragm). Conduction studies are imperative to rule out motor neuropathy with multifocal conduction block. Various techniques (cortical threshold, cortical silent period, double stimulation) employing transcranial magnetic stimulation have demonstrated that the motor cortex in ALS is hyperexcitable. Central motor conduction is normal in ALS but uniquely slow in the D9OA SOD1 mutation. Using peristimulus time histograms (PSTHs) it is possible to estimate the size of a unitary excitatory postsynaptic potential (EPSP). In ALS the EPSP is typically desynchronized. With time it becomes reduced in amplitude and a slow conducting component becomes recognizable in the primary peak of the PSTH. This reflects conduction through a slow motor pathway. Abnormalities of the PSTH are not seen in Kennedy's disease, implying that the changes seen in ALS are due to supraspinal mechanisms.

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Section: Motor Unit Estimatesmentioning

confidence: 98%

Section: Motor Unit Estimatesmentioning

confidence: 99%

Clinical Electrophysiology of the Upper and Lower Motor Neuron in Amyotrophic Lateral Sclerosis

Eisen

2001

Semin Neurol

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“…Motor unit number estimates (MUNEs) provide information related to the number of functioning motor neurons or motor axons in a given muscle or muscle group 2, 6–8, 11. This information is useful when evaluating the extent of motor unit (MU) loss associated with motor neuron disease or peripheral neuropathy and when assessing the course and outcome of treatment for these disorders 3, 11, 17, 19…”

mentioning

confidence: 99%

“…Each of the currently available methods—which include incremental stimulation, multiple point stimulation (MPS), the statistical method, and spike‐triggered averaging (STA)—has a number of positive and negative features that make them more or less applicable in a given clinical situation 1, 8, 21, 26, 27. If one assumes that all the aforementioned MUNE methods are valid, their clinical utility or usefulness as an outcome measure is predominantly dependent on their ease of use and reliability 2, 6, 8, 21…”

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confidence: 99%

Influence of acetate-free biofiltration on intradialytic cardiovascular stability

Petrović¹

2006

Dial. Transplant.

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Background. Acetate-free biofiltration (AFB) is a diffusive-convective dialysis procedure that utilizes a high-flux membrane (AN69), postdilution infusion of sodium bicarbonate solution, and a dialysate that is completely free of any buffer. The AFB technique may provide better cardiovascular stability and reduce intradialytic side effects. The aim of the present study was to investigate the influence of AFB, compared with bicarbonate dialysis (HD), on intradialytic cardiovascular stability and dialysisinduced morbidity. Patients and Methods. The study included 5 patients with end-stage renal disease. Their mean age was 57.2 AE 1.6 years, and they had been undergoing hemodialysis (HD) for an average of 25 AE 22 months. The patients were followed for 1 year: they were treated first with HD for 6 months, followed by 6 months on AFB, maintaining all the dialytic parameters used during the HD. While the patients were on HD and AFB, we evaluated the number of episodes of intradialytic hypotension (IDH); the episodes of muscle cramps, nausea, headache (dialysis intolerance); dry body weight; and intradialysis weight loss. Data on dialysis adequacy and serum biochemistry were obtained monthly, and albumin and cholesterol were determined every 3 months. Results. The results showed that after the switch from HD to AFB, there was a significant reduction in IDH (36.8% on HD, 13.5% on AFB; p < 0.005) and in symptoms of dialysis intolerance (15.8% on HD, 2.8% on AFB; p < 0.005). Intradialysis weight loss increased significantly on AFB (3.47 kg on HD, 3.63 kg on AFB; p < 0.005), whereas dry body weight remained stable. Postdialysis systolic blood pressure increased significantly on AFB (132.6 AE 7.7 mmHg on HD, 140.6 AE 5.4 mmHg on AFB; p < 0.005). Post-dialysis diastolic blood pressure was also higher on AFB (76.9 AE 4.9 mmHg on HD, 81.8 AE 3.4 mmHg on AFB; p < 0.005). The other parameters observed remained unchanged. Conclusion. The percentage of dialysis sessions in which IDH and symptoms of dialysis intolerance occurred decreased significantly on AFB. AFB provided better control of dry body weight and post-dialysis systolic and diastolic blood pressure than did HD. These results show that AFB reduces intradialytic symptoms and improves patient quality of life.

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A Clearer View of Upper Motor Neuron Dysfunction in Amyotrophic Lateral Sclerosis

Elliott¹

1998

Arch Neurol

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Quantitative methods for estimating the number of motor units in human muscles

Cited by 7 publications

References 14 publications

Clinical Electrophysiology of the Upper and Lower Motor Neuron in Amyotrophic Lateral Sclerosis

Clinical Electrophysiology of the Upper and Lower Motor Neuron in Amyotrophic Lateral Sclerosis

Influence of acetate-free biofiltration on intradialytic cardiovascular stability

A Clearer View of Upper Motor Neuron Dysfunction in Amyotrophic Lateral Sclerosis

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