Sensory (VEP, BAEP, SEP) and Motor-Evoked Potentials, Liquoral and Magnetic Resonance Findings in Multiple Sclerosis

Abstract

In order to define the most suitable instrumental protocol for the diagnosis of multiple sclerosis (MS), 41 patients with definite (D = 14), probable (P = 14) and suspected (S = 13) MS were examined with CSF immunology, brain MRI and multimodal evoked potentials. The central motor tracts were also tested. The following alteration rates were found: MRI = 78%, CSF = 63.6%, VEP = 70.0%, median nerve SEP = 50%, peroneal nerve SEP = 68.0%, BAEPs =35.7%, motor-evoked potentials (MEPs) = 74.0%. Altogether, EPs were abnormal in 90% of cases. Normal MRI with altered EPs were found in 22% of cases, whilst a normal EP battery with defective CSF or MRI findings were found in 7%. Twenty-six out of 27 patients with P or S forms were reclassified into a D one when considering EPs and MRI features.

Visual and motor evoked potentials in the course of multiple sclerosis

“…Cross-sectional analysis of our data shows that VEP results correlate with visual acuity and MEP results and the combined VEP and MEP results correlate with the EDSS score at all points in time. The correlations are closer than those reported between MRI findings and EDSS score and corroborate earlier studies by others (Nuwer et al, 1987;Rossini et al, 1989;Kandler et al, 1991;Salle et al, 1992;Brigell et al, 1994;Andersson et al, 1995;Facchetti et al, 1997;Davies et al, 1998;O'Connor et al, 1998). The most parsimonious explanation for this is that, unlike MRI abnormalities, each pathological evoked potential measurement represents at least one zone of malfunction, even if it is subclinical and of microscopical dimensions.…”

Visual and motor evoked potentials in the course of multiple sclerosis

“…Cross-sectional analysis of our data shows that VEP results correlate with visual acuity and MEP results and the combined VEP and MEP results correlate with the EDSS score at all points in time. The correlations are closer than those reported between MRI findings and EDSS score and corroborate earlier studies by others (Nuwer et al, 1987;Rossini et al, 1989;Kandler et al, 1991;Salle et al, 1992;Brigell et al, 1994;Andersson et al, 1995;Facchetti et al, 1997;Davies et al, 1998;O'Connor et al, 1998). The most parsimonious explanation for this is that, unlike MRI abnormalities, each pathological evoked potential measurement represents at least one zone of malfunction, even if it is subclinical and of microscopical dimensions.…”

Definite and Suspected Multiple Sclerosis in Children: Long-Term Follow-up and Magnetic Resonance Imaging Findings

“…Our findings disclose prolonged interwave I-V separations often accompanied by a loss of amplitude of wave V. Transcranial magnetic stimulation of the motor cortex may show prolongation of central conduction times, a higher than normal excitability threshold, and hypovolted as well as temporally dispersed and polyphasic motor evoked potentials. 24 Our findings of prolonged central conduction time on transcranial magnetic stimulation do not always correlate with the clinical manifestations and the localization of the lesions of demyelination on MRI. A correlation is essential to be made between the findings of these methods of investigation and MRI data in cases with abnormal MRI, bearing in mind that pathologic findings on transcranial magnetic stimulation, visual evoked potentials, and brainstem auditory evoked responses are present in other demyelinating diseases as well.…”

The physiological basis of conduction slowing in ALS patients homozygous for the D90A CuZn-SOD mutation

“…We previously performed a detailed neurophysiological study comparing sporadic ALS with D90A patients, which confirmed markedly slow central conduction in D90A patients 63. Because slow central conduction is typical of demyelinating disorders30, 34, 40, 53, 55 we used a different approach in the present study, comparing peristimulus time histograms (PSTHs) after transcranial magnetic stimulation (TMS) in patients homozygous for the D90A mutation and in multiple sclerosis (MS) patients. Unlike routine motor evoked potentials (MEPs), which give no information regarding a select group of corticomotoneurons, this technique allows detailed analysis of a limited number of corticomotoneurons converging onto a single anterior horn cell.…”

Visual and motor evoked potentials in the course of multiple sclerosis

“…Cross-sectional analysis of our data shows that VEP results correlate with visual acuity and MEP results and the combined VEP and MEP results correlate with the EDSS score at all points in time. The correlations are closer than those reported between MRI findings and EDSS score and corroborate earlier studies by others (Nuwer et al, 1987;Rossini et al, 1989;Kandler et al, 1991;Salle et al, 1992;Brigell et al, 1994;Andersson et al, 1995;Facchetti et al, 1997;Davies et al, 1998;O'Connor et al, 1998). The most parsimonious explanation for this is that, unlike MRI abnormalities, each pathological evoked potential measurement represents at least one zone of malfunction, even if it is subclinical and of microscopical dimensions.…”

Definite and Suspected Multiple Sclerosis in Children: Long-Term Follow-up and Magnetic Resonance Imaging Findings

“…Our findings disclose prolonged interwave I-V separations often accompanied by a loss of amplitude of wave V. Transcranial magnetic stimulation of the motor cortex may show prolongation of central conduction times, a higher than normal excitability threshold, and hypovolted as well as temporally dispersed and polyphasic motor evoked potentials. 24 Our findings of prolonged central conduction time on transcranial magnetic stimulation do not always correlate with the clinical manifestations and the localization of the lesions of demyelination on MRI. A correlation is essential to be made between the findings of these methods of investigation and MRI data in cases with abnormal MRI, bearing in mind that pathologic findings on transcranial magnetic stimulation, visual evoked potentials, and brainstem auditory evoked responses are present in other demyelinating diseases as well.…”

The physiological basis of conduction slowing in ALS patients homozygous for the D90A CuZn-SOD mutation

“…We previously performed a detailed neurophysiological study comparing sporadic ALS with D90A patients, which confirmed markedly slow central conduction in D90A patients 63. Because slow central conduction is typical of demyelinating disorders30, 34, 40, 53, 55 we used a different approach in the present study, comparing peristimulus time histograms (PSTHs) after transcranial magnetic stimulation (TMS) in patients homozygous for the D90A mutation and in multiple sclerosis (MS) patients. Unlike routine motor evoked potentials (MEPs), which give no information regarding a select group of corticomotoneurons, this technique allows detailed analysis of a limited number of corticomotoneurons converging onto a single anterior horn cell.…”

Visual and motor evoked potentials in the course of multiple sclerosis

“…Cross-sectional analysis of our data shows that VEP results correlate with visual acuity and MEP results and the combined VEP and MEP results correlate with the EDSS score at all points in time. The correlations are closer than those reported between MRI findings and EDSS score and corroborate earlier studies by others (Nuwer et al, 1987;Rossini et al, 1989;Kandler et al, 1991;Salle et al, 1992;Brigell et al, 1994;Andersson et al, 1995;Facchetti et al, 1997;Davies et al, 1998;O'Connor et al, 1998). The most parsimonious explanation for this is that, unlike MRI abnormalities, each pathological evoked potential measurement represents at least one zone of malfunction, even if it is subclinical and of microscopical dimensions.…”

Definite and Suspected Multiple Sclerosis in Children: Long-Term Follow-up and Magnetic Resonance Imaging Findings

“…Our findings disclose prolonged interwave I-V separations often accompanied by a loss of amplitude of wave V. Transcranial magnetic stimulation of the motor cortex may show prolongation of central conduction times, a higher than normal excitability threshold, and hypovolted as well as temporally dispersed and polyphasic motor evoked potentials. 24 Our findings of prolonged central conduction time on transcranial magnetic stimulation do not always correlate with the clinical manifestations and the localization of the lesions of demyelination on MRI. A correlation is essential to be made between the findings of these methods of investigation and MRI data in cases with abnormal MRI, bearing in mind that pathologic findings on transcranial magnetic stimulation, visual evoked potentials, and brainstem auditory evoked responses are present in other demyelinating diseases as well.…”

The physiological basis of conduction slowing in ALS patients homozygous for the D90A CuZn-SOD mutation

“…We previously performed a detailed neurophysiological study comparing sporadic ALS with D90A patients, which confirmed markedly slow central conduction in D90A patients 63. Because slow central conduction is typical of demyelinating disorders30, 34, 40, 53, 55 we used a different approach in the present study, comparing peristimulus time histograms (PSTHs) after transcranial magnetic stimulation (TMS) in patients homozygous for the D90A mutation and in multiple sclerosis (MS) patients. Unlike routine motor evoked potentials (MEPs), which give no information regarding a select group of corticomotoneurons, this technique allows detailed analysis of a limited number of corticomotoneurons converging onto a single anterior horn cell.…”