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Michael Swash

Publications and source records attributed to Michael Swash.

At least 19 recordsLinked to original sources
PubMed2005

Quantitating progression in ALS.

The authors prospectively studied the value of clinical and neurophysiologic measurements in assessing progression in ALS. Motor unit number estimation (MUNE) and the neurophysiologic index (NI) were significantly correlated with ADM strength (maximal voluntary isometric contraction force in the abductor digiti minimi muscle [MVIC-ADM]). MUNE and the NI were reliable, but the NI showed a lower variation. On assessing progression at 3, 6, and 12 months, MUNE, NI, and MVIC-ADM showed the highest rate of change. The NI is a potentially useful new neurophysiologic measurement.

Adult↗
PubMed2005

Neurophysiological measures in amyotrophic lateral sclerosis: markers of progression in clinical trials.

In this review we evaluate clinical neurophysiological methods, originally described for use in diagnosis that can be applied to measurement of change during the progress of amyotrophic lateral sclerosis (ALS). Such measurements are potentially important in clinical trials, and also in clinical practice. We have assessed methods for lower and upper motor neuron function, including conventional EMG, nerve conduction and F-wave studies, the derived Neurophysiological Index, motor unit counting methods (MUNE), and transcranial magnetic motor cortex stimulation. We have also addressed the validity of measurements of electromechanical coupling. Methods for measuring muscle strength are beyond the scope of this review. We conclude that MUNE, M-wave amplitude and the Neurophysiological Index are sufficiently reliable, sensitive, and relevant to the clinical problem of ALS, to be used in clinical trials in the disease. Transcranial magnetic stimulation is of limited value, but a combination of the measurements made as part of this technique may also be useful. We conclude that clinical neurophysiological techniques should now be used in measuring change in clinical trials in ALS.

Amyotrophic Lateral Sclerosis↗
PubMed2004

Cramps, muscle pain, and fasciculations: not always benign?

Fasciculation and cramps without weakness or muscle atrophy are recognized as a benign syndrome. The authors report a patient with cramp and fasciculation, which persisted for 1 year without abnormal motor unit morphology on EMG before progressive weakness, muscle atrophy, and EMG abnormalities developed. This observation raises the possibility that lower motor neuron hyperexcitability may precede motor neuron death in motor neuron disease.

Accidental Falls↗
PubMed2004

Sarcoid polyneuropathy responsive to intravenous immunoglobulin.

We describe a 38-year-old woman with a predominantly sensory axonal polyneuropathy in whom a nerve biopsy demonstrated sarcoid granulomas. The neuropathy did not respond to oral steroid therapy but there was a rapid and repeated response to intravenous immunoglobulin, which gradually diminished over subsequent treatments, but remained beneficial. The systemic sarcoidosis remained active.

Adult↗
PubMed2004

Analysis of force profile during a maximum voluntary isometric contraction task.

This study analyses maximum voluntary isometric contraction (MVIC) and its measurement by recording the force profile during maximal-effort, 7-s hand-grip contractions. Six healthy subjects each performed three trials repeated at short intervals to study variation from fatigue. These three trials were performed during three separate sessions at daily intervals to look at random variation. A pattern of force development during a trial was identified. An initiation phase, with or without an initiation peak, was followed by a maintenance phase, sometimes with secondary pulses and an underlying decline in force. Of these three MVIC parameters, maximum force during the maintenance phase showed less random variability compared to intertrial fatigue variability than did maximum force during the initiation phase or absolute maximum force. Analysis of MVIC as a task, rather than a single, maximal value reveals deeper levels of motor control in its generation. Thus, force parameters other than the absolute maximum force may be better suited to quantification of muscle performance in health and disease.

Adult↗
PubMed2004

Amyotrophic lateral sclerosis: a consensus viewpoint on designing and implementing a clinical trial.

In November 2002, an advisory board meeting was convened by Novartis Pharma to provide recommendations and rationale for clinical trials designed to evaluate new treatments, such as TCH346, for amyotrophic lateral sclerosis (ALS). In terms of selecting appropriate outcome measures, the panel recommended the use of the ALS Functional Rating Scale (ALSFRS-R) to measure primary endpoints. A review of other key issues in this area including regional variations in the epidemiology, diagnosis and management of ALS, defining patient populations and doses of trial medication, and accommodating the likelihood of co-medication with pre-existing treatment in trial design, are discussed.

Amyotrophic Lateral Sclerosis↗
PubMed2004

The Neurophysiological Index in ALS.

The Neurophysiological Index (NI) consists of a mathematical derivation of three standardised neurophysiological measurements. Since these measurements are part of routine practice in any clinical neurophysiology laboratory, calculation of the NI is within the capability of any laboratory. The NI is derived from the CMAP, the DML and the F-wave frequency (CMAP amplitude/DML) x F frequency %), representing aspects of the effects of denervation and reinnervation, of degeneration of the terminal part of the motor axons, and of the excitability of anterior horn cells. We have shown that this simple index is reproducible in consecutive studies of normal subjects and of patients with ALS (intra-rater reliability), and is sensitive to change. In ALS, the NI differentiates rapidly and slowly progressive disease at least as sensitively as other measures in common use, including the ALS-FRS. We propose that the NI could be used as a sensitive measure of change during the course of ALS and its treatment. In combination with relevant measures of clinical benefit, such as ALS-FRS and a QoL measure, this could simplify trial design and allow more rapid determination of the efficacy of putative new therapies in clinical trials.

Amyotrophic Lateral Sclerosis↗
PubMed2003

Motor responses evoked by transcranial magnetic stimulation and peripheral nerve stimulation in the ulnar innervation in amyotrophic lateral sclerosis: the effect of upper and lower motor neuron lesion.

We studied the upper (UMN) and lower motor neuron (LMN) innervations of 159 hands from 81 patients with amyotrophic lateral sclerosis (ALS). Eleven patients with various chronic LMN disorders causing weakness in the abductor digiti minimi (ADM) muscle served as LMN controls. Thirty healthy subjects served as normal controls. Cortical motor threshold, central conduction time (CMCT), and motor-evoked response amplitude (MEP) after transcranial magnetic stimulation (TMS) were studied, and the MEP/M wave ratio was calculated. The data was analyzed in the ALS subjects in groups defined by ADM muscle strength and by the presence or absence of clinical signs of UMN involvement. CMCT was not increased in the ALS or LMN disease groups. The threshold was higher in limbs with both weak ADM muscles and UMN signs. The MEP/M wave amplitude ratio was increased in weak muscles in the ALS patients, notably in limbs with no UMN signs, and also in weak muscles in patients with other chronic LMN disorders. It was frequently decreased in strong muscles. There was no difference between bulbar-onset and limb-onset ALS groups, and there was no correlation between threshold and disease duration. We suggest that expressing the data as an index and utilising the MEP/M wave amplitude ratio as a variable is a sensitive method for detecting UMN abnormality in ALS in particular in early affected muscles.

Adult↗
PubMed2003

Clinical and neurophysiological evaluation of progression in amyotrophic lateral sclerosis.

There is a need for a sensitive neurophysiological measure of disease progression in following the course of patients with amyotrophic lateral sclerosis (ALS). We studied two groups of nine ALS patients, one with slow progression (Group A) and the other with rapid progression (Group B). We evaluated muscle strength scores using the Medical Research Council (MRC) scale in limb and trunk muscles, forced vital capacity (FVC), and ALS functional rating scale (ALS-FRS) scores. Maximal voluntary isometric contraction (MVIC) of the abductor digiti minimi muscle (ADM) was measured, using a digital device. We also measured M-wave amplitude and area in the ADM, and the distal motor latency and F-wave frequency in the ulnar nerve; from these data, the neurophysiological index (NI) was calculated, as described previously. In both groups, the NI was the most sensitive measure of change, with the smallest coefficient of variation. We conclude that the NI, which requires no special technology and no new clinical or technical skills to use, is sensitive to change, and therefore may be useful in clinical trials, as well as in a clinical setting.

Adolescent↗
PubMed2003

Factors which predict physical and mental health status in patients with amyotrophic lateral sclerosis over time.

OBJECTIVES: To determine which factors are predictive of physical and mental health one year after a first measurement of health status in amyotrophic lateral sclerosis (ALS) patients. METHODS: The Physical Component Summary (PCS) score and the Mental Component Summary (MCS) score of the SF-36 were used as the main outcome measures in patients enrolled in the European ALS Health Profile Study (ALS-HPS). Correlation and stepwise regression procedures were used to determine the relationship between patients' physical and mental health status at follow-up with baseline measures. RESULTS: A total of 1118 patients were recruited into the ALS-HPS, of which 918 (82.11%) returned fully or partially completed baseline and follow-up surveys. PCS scores declined over time. No significant changes were reported for the MCS scores over time for patients with ALS. Baseline scores were found to be significant predictors of patients' health status over time. CONCLUSIONS: Overall, patients' physical health status at the time of recruitment was the major predictor of the physical health status at both first and second follow-up time assessments. The same relationship was found between baseline and follow-up mental health status. The study also confirms the appropriateness of the use of the SF-36 in ALS patients.

Activities of Daily Living↗
PubMed2003

Hospital founders.

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History, 17th Century↗
PubMed2002

What does the neurologist expect from clinical neurophysiology?

The future role of clinical neurophysiology is considered in the light of its achievements. It is argued that there is a need to develop methods for specific diagnosis, especially in neuropathies. There is also an unmet requirement for the development of techniques for the prediction of treatment outcomes and for the measurement of changes during the natural history of neuromuscular disorders and their treatment. These issues are not addressed by currently available clinical test methods.

Electromyography↗