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

Carvalho, Mamede de; Turkman, Maria Antónia Amaral; Swash, Michael

doi:10.1016/s0022-510x(03)00024-8

Cited by 53 publications

(30 citation statements)

References 35 publications

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“…One of our most striking findings is that TMS was more sensitive than clinical examination in patients with suspected or possible ALS, revealing UMN dysfunction in 75% (9 of 12) of the upper limbs. The sensitivity of CMCT in supporting the diagnosis reportedly increases with the number of muscles studied, 10,12,14,35,38,40,47 and this may apply to the parameters studied herein. We believe that, as for electromyography, several regions of the body, including muscles innervated by bulbar nerves, should be tested to increase the sensitivity of TMS in supporting a diagnosis of ALS.…”

Section: Discussionmentioning

confidence: 56%

“…Transcranial magnetic stimulation (TMS) is a useful tool for diagnosing UMN dysfunction in ALS and provides a sensitive means of assessing cortical excitatory and inhibitory dysfunction. 10,12,14,35,38,40,47 The most frequently studied variables, which are generally recorded by conventional TMS using simple stimulation techniques, are central motor conduction time (CMCT), amplitude of motor evoked potentials (MEPs), resting motor threshold (RMT), and duration of silent period (SP). CMCT is reportedly not a sensitive variable for the diagnosis of ALS.…”

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confidence: 99%

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Magnetic stimulation including the triple‐stimulation technique in amyotrophic lateral sclerosis

2007

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To study the relative importance of upper motor neuron (UMN) dysfunction in the weakness of amyotrophic lateral sclerosis (ALS) and to compare the sensitivity of several transcranial magnetic stimulation (TMS) parameters as means of assessing UMN impairment in ALS, we used TMS to evaluate one upper limb of 63 patients. The triple-stimulation technique (TST) and silent period (SP) were found to be the most frequently abnormal parameters (55.6% and 47.6%, respectively), without significant difference in their diagnostic sensitivity. The SP was found to be a useful parameter in patients with suspected or possible ALS. A positive correlation was found between weakness and the TST amplitude ratio, indicating that weakness may partly be caused by UMN dysfunction. Thus, the TST provides a quantitative tool for assessing UMN conduction failure. When used in association with the SP, the TST provides a sensitive diagnostic tool for use on ALS patients.

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Section: Discussionmentioning

confidence: 56%

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confidence: 99%

Magnetic stimulation including the triple‐stimulation technique in amyotrophic lateral sclerosis

2007

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“…A Keypoint machine (Dantec, Skovlunde, Denmark) was used for the neurophysiological studies. The temperature of the Abbreviations: ADM, abductor digiti minimi muscle; ALS, amyotrophic lateral sclerosis; ALS-FRS, amyotrophic laterals sclerosis functional rating scale; CSP, cortical silent period; CMAP, compound muscle action potential; EMG, electromyogram; FVC, forced vital capacity; LMN, lower motor neuron; MEP, motor evoked potential; MUNE, motor unit number estimation; MRC, Medical Research Council (UK); NI, Neurophysiological Index; UMN, upper motor neuron Correspondence to: M. de Carvalho; e-mail: mamedemg@mail.telepac.pt investigated limb was kept at 32 C. Motor unit number estimation (MUNE), 2,3 the Neurophysiological Index (NI), 3 and transcranial magnetic stimulation (TMS) 6 were evaluated at each test session. For MUNE measurements we used the incremental technique.…”

Section: Methodsmentioning

confidence: 99%

“…6 The center of the coil was positioned flat over the vertex, but it was moved as necessary to obtain a maximal response at the lowest stimulus intensity. The subjects were asked to keep the hand relaxed, as monitored through the surface electrodes by the audio system of the EMG device.…”

Section: Methodsmentioning

confidence: 99%

“…In each subject 10 or more responses were obtained, with an interstimulus interval of at least 30 s. The MEP with highest amplitude was accepted for latency and MEP amplitude measurements. 6 The ratio MEP/CMAP wave amplitude Â 100 was calculated, obtaining Mwave amplitude by stimulation of the ulnar nerve at the wrist. When the MEP was absent, a threshold value of 100% was assigned.…”

Section: Methodsmentioning

confidence: 99%

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Sensitivity of electrophysiological tests for upper and lower motor neuron dysfunction in ALS: A six‐month longitudinal study

Carvalho

Swash

2009

Muscle and Nerve

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By following a group of amyotrophic lateral sclerosis (ALS) patients longitudinally using lower motor neuron (LMN) and upper motor neuron (UMN) markers of dysfunction it may be possible to better understand the functional relationships between these motor systems in this disease. We used neurophysiological techniques to follow UMN and LMN dysfunction in a group of 28 patients with ALS, in comparison with the ALS functional rating scale (ALS-FRS) score and the forced vital capacity (FVC). We used motor unit number estimation (MUNE), compound muscle action potential (CMAP) amplitude, and the Neurophysiological Index (NI) to quantify the LMN disorder, and transcranial motor stimulation to study cortical motor threshold, motor-evoked response amplitude, central motor conduction time, and cortical silent period (CSP). The patients were studied shortly after diagnosis and then 6 months later, using both abductor digiti minimi muscles (ADM); ADM strength was initially >MRC 3 (Medical Research Council, UK). The NI and MUNE changed more than any other variable. CSP increased by about 30%, a change more marked than the slight increase observed in the cortical motor threshold (9%). The normal increase of CSP after acute muscle fatigue was preserved during disease progression. The CSP increase correlated with the MUNE rate of decay but not to the NI reduction, perhaps because NI includes F-wave frequency in itscalculation. There was no definite correlation between UMN and LMNdysfunction or progression, but there was a link between CSP and LMN changes in ALS. The CSP may be a useful variable in following UMN dysfunction in clinical practice and in clinical trials.

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Electrodiagnostic studies in the management and prognosis of neuromuscular disorders

Gilchrist

Sachs

2003

Muscle and Nerve

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Prognosis remains a neglected aspect of modern medical care and research, behind diagnosis and treatment. The very term "electrodiagnosis" implies as much. Despite this, much has been published regarding the use and benefit of electrodiagnostic techniques in assessing prognosis and assisting in management of patients after the diagnosis has been established. This information is often hidden or otherwise not emphasized. This review summarizes the literature regarding the use of such techniques for prognosis and management of disorders of lower motor neurons, peripheral nerves, neuromuscular transmission, and muscle.

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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

Cited by 53 publications

References 35 publications

Magnetic stimulation including the triple‐stimulation technique in amyotrophic lateral sclerosis

Magnetic stimulation including the triple‐stimulation technique in amyotrophic lateral sclerosis

Sensitivity of electrophysiological tests for upper and lower motor neuron dysfunction in ALS: A six‐month longitudinal study

Electrodiagnostic studies in the management and prognosis of neuromuscular disorders

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