Correlation between multimodal evoked potentials and magnetic resonance imaging in multiple sclerosis

Summary Sixty multiple sclerosis (MS) patients (33 definite, 13 probale and 14 suspected were investigated by computed tomography (CT), magnetic resonance imaging (MRI), multimodality evoked potentials (EPs) and cerebrospinal fluid (CSF) electrophoresis. MRI abnormalities were found in 50 cases, while at least one abnormal evoked potential was detected in each of 52 cases. Brain-stem auditory evoked potentials were more sensitive than MRI for the detection of brainstem involvement. All the patients with oligoclonal bands had abnormal MRI and none of the patients with normal MRI had oligoclonal bands in the CSF. The number and the extent of MRI lesions were significantly correlated with the duration of disease and with the degree of disability. Our observations stress the importance of the combined use of MRI and EPs in detecting silent CNS lesions in MS patients.     

Evaluation of patients with multiple sclerosis by evoked potentials and magnetic resonance imaging: a comparative study

We compared the diagnostic usefulness of evoked potential (EP) studies and magnetic resonance imaging (MRI) in the evaluation of 27 patients with definite or probable multiple sclerosis (MS). MRI scans demonstrated multiple lesions in 21 patients whereas EP studies showed multiple abnormalities in 14 patients (4 of whom had only somatosensory EP abnormalities). Eighteen patients had similar MRI and EP results (e.g., normal or multiple abnormalities), 8 had multiple abnormalities shown by MRI but normal or single-modality abnormal EPs, and 1 had multiple abnormal EPs but a normal MRI scan. There was no significant difference in the sensitivity of the two techniques in detecting multiple lesions in the patients with definite MS, whereas among those with probable MS, MRI had a significantly higher yield. Seventeen patients showed clinical evidence of posterior fossa involvement, 6 patients had abnormal brainstem auditory evoked potentials (BAEPs), and 4 patients had areas of increased signal intensity revealed by MRI of the brainstem. There was no clinical evidence of brainstem involvement in 2 patients with BAEP abnormalities, 2 with an abnormal posterior fossa shown by MRI, and one patient with abnormalities shown by both BAEP and MRI. We conclude that MRI is more sensitive in detecting multiple lesions than are multimodality EP studies, but that BAEP assessment may be slightly more sensitive than MRI in detecting brainstem lesions.     

Brain magnetic resonance imaging and multimodal evoked potentials in benign and secondary progressive multiple sclerosis.

Brain MRI and multimodal evoked potentials (EPs) were obtained for 13 patients with benign multiple sclerosis and 13 patients with secondary progressive multiple sclerosis, matched for age and duration of the disease, to investigate the nature of the disability in multiple sclerosis. Patients with secondary progressive multiple sclerosis had significantly greater lesion loads for five of seven periventricular regions and for three of nine regions separate from the ventricles. Patients with secondary progressive multiple sclerosis also had more severe infratentorial atrophy scores (p = 0.04), whereas there were no differences between the two groups in number and extent of enhancing lesions. The frequencies were significantly higher and severities greater for multimodal EP abnormalities of all the modalities in patients with secondary progressive multiple sclerosis. At least one EP component was absent in 12 (92%) patients with secondary progressive multiple sclerosis but in only one patient (8%) with benign multiple sclerosis (p < 0.001). There was neurophysiological evidence for cervical cord involvement in eight (61%) patients with secondary progressive multiple sclerosis and in one with benign multiple sclerosis (p < 0.01). These data indicate that the total amount of lesions, the distribution, and the nature of the pathological process might all account for the development of disability in multiple sclerosis.     

多发性硬化患者头颅磁共振、诱发电位和IgG指数的对比研究

报道43例多发性硬化(MS)患者头颅磁共振成像(MRI)、诱发电位(EP)和IgG指数(IgGIndex)的对比研究结果。发现MRI的检测异常率为81.4％,而VEP仅53.7％、BAEP47.5％、IgGIndex57.5％。MRI在显示空间脱髓鞘方面是最敏感的方法,但VEP、BAEP只要有一项异常即判断为EP异常则其异常率高达79.5％,接近MRI。作者认为三者同时检查可以提高诊断的准确性。     

Prognostic value of multimodal evoked potentials in multiple sclerosis: the EP score

Evoked potentials (EPs) have long been used as diagnostic tools in multiple sclerosis (MS), although their importance decreased as magnetic resonance imaging (MRI) became available. However, the prognostic value of EPs in MS has not been completely established. The aim of the study was to analyze the prognostic significance of EPs in a cohort of MS cases. From the Verona University Hospital MS Clinic database we retrospectively identified 80 MS patients who underwent a complete neurophysiological evaluation, including visual, brain stem, somatosensory and motor EPs and who were followed for at least 5 years after the study. EPs abnormalities were quantified through an index of global EPs alteration (EP score). The relationship between EP score and disability in terms of Expanded Disability Status Scale (EDSS) was analyzed by the Kaplan–Meier survival method and Spearman ρ correlation coefficient. ROC curves were used to determine the best EP score cut off to predict different EDSS endpoints. For each endpoint, sensitivity, specificity, positive and negative predictive value of EP score were calculated. We found a significant correlation (p < 0.001) between EP score and EDSS score at the time of neurophysiological study and at 1, 3 and 5 years of follow-up, particularly for motor and somatosensory EPs. Kaplan–Meier curves confirmed an increased risk of disability in those patients with EP score higher than the median value. EP score of 8 or 9 showed the highest sensitivity and specificity in predicting EDSS 4.0 and 6.0. EPs are reliable procedures to predict disability in MS patients. The correlation between EPs abnormalities and EDSS is higher than between conventional MRI and EDSS.     

The sensitivity of multimodal evoked potentials in multiple sclerosis. A comparison with magnetic resonance imaging and cerebrospinal fluid analysis

Since magnetic resonance imaging (MRI) has proved to be a valuable method in assessing multiple sclerosis (MS) patients, some studies have aimed at comparing the sensitivities of MRI, multimodality evoked potentials (MEPs) and cerebrospinal fluid (CSF) analysis for oligoclonal banding, with somewhat conflicting results. It is suggested that these differences can be largely explained by the criteria used for patient incorporation, on the one hand, and by the way of recording MEPs, on the other. This hypothesis is confirmed by the present study which shows that, when only patients with definite MS are selected, and with optimal conditions of MEP recording (norms adapted to patient parameters, use of several spatial frequencies, combined stimulation of median and posterior tibial nerves), the sensitivities of MRI, MEPs and CSF are high and do not significantly differ from each other.     

诱发电位和MRI检查在多发性硬化诊断中的价值

目的探讨诱发电位(EPs)和MRI检查在多发性硬化(MS)诊断中的价值。方法收集69例MS患者的临床资料、视觉诱发电位、体感诱发电位、脑干听觉诱发电位、磁刺激运动诱发电位以及MRI结果,比较不同检测方法对其临床诊断的价值。结果 MS患者的视觉诱发电位、体感诱发电位、听觉诱发电位、运动诱发电位以及MRI的异常检出率分别为69.57%(48/69)、50.72%(35/69)、55.07%(38/69)、42.03%(29/69)、78.26%(54/69)。4项诱发电位检查总异常检出率为86.96%(60/69),与MRI检查结果比较差异无统计学意义(P=0.178)。EPs和MRI检查均能发现临床下病灶:14例患者经MRI检查发现病灶但无相应临床症状;15例患者有临床症状而MRI检查未见相应病灶,但EPs检查可见异常。结论 MRI和EPs检查具有相互补充作用,结合临床合理选择使用此两种检查有助于提高MS诊断的敏感性。     

Angiographically occult brainstem vascular malformation: a longitudinal comparison of magnetic resonance imaging (MRI) and multimodal evoked potential (EP) recordings.

Over a period of several years, a patient with angiographically occult vascular malformation (AOVM) involving the brainstem was longitudinally studied by means of serial Magnetic Resonance Imaging (MRI) and multimodal Evoked Potential (EP) recordings (visual-VEP, brainstem auditory-BAEP, somatosensory--SEP--by stimulating median and peroneal nerves). MRI did contribute to an accurate definition of AOVM features. In particular, it was able to follow over time the AOVM size, and to discriminate between recent and old bleedings. Multimodal EP recordings displayed different pathological BAEP and peroneal SEP values, which documented a transient segmental brainstem involvement (related to the presence of hemorrhage), along with persistent and probably irreversible signs of diffuse brainstem dysfunction. Thus, MRI and EP assessment is useful in monitoring the clinical course of brainstem occult vascular malformations.     

Trimodal evoked potentials compared with magnetic resonance imaging in the diagnosis of multiple sclerosis

Twenty-three patients with the clinical diagnosis of possible multiple sclerosis (MS) were tested with magnetic resonance imaging (MRI) and trimodal evoked potentials. Fourteen patients showed abnormalities on both MRI scans and at least one evoked potential modality (65%). Four patients had normal MRI scans but at least one abnormality on evoked potential testing (17%). One patient had normal triple evoked potentials with an abnormal MRI result. Four patients had normal results on both MRI and triple evoked potential testing; two of these patients were later found to have immunologic abnormalities in the cerebrospinal fluid consistent with the diagnosis of MS. Combined evoked potential testing was found to have a higher sensitivity than MRI in confirming a diagnosis of MS. Three patients with the clinical diagnosis of definite MS were also tested. All these patients showed abnormalities on evoked potential testing, although one patient had a normal MRI result. Of all 26 patients who were studied, 17 showed abnormal MRI results and 21 showed at least one abnormality on evoked potential testing.     

Somatosensory evoked potentials and magnetic resonance imaging of the central nervous system in early multiple sclerosis

Journal of Neurology - Somatosensory evoked potentials (SSEP) are still broadly used, although not explicitly recommended, for the diagnostic work-up of suspected multiple sclerosis (MS). To relate...     

多发性硬化患者的MRI及多种诱发电位研究

目的探讨磁共振成像(MRI)和诱发电位(EPs)在诊断多发性硬化中的价值。方法对68例多发性硬化患者的头颅MRI、脑干听觉诱发电位、视觉诱发电位以及体感诱发电位等指标进行回顾性分析和比较。结果多发性硬化患者的头颅MRI、脑干听觉诱发电位、视觉诱发电位以及体感诱发电位的异常率分别为91.2%(62/68)、80.9%(55/68)、82.4%(56/68)和77.9%(53/68),且均发现多发性硬化的亚临床病灶;两项或多项联合检查的异常率较单项检查的异常率增高,差异有统计学意义(P<0.01)。结论头颅MRI和诱发电位检查有助于临床早期确诊多发性硬化,联合应用可使其敏感性提高。     

The utility of multimodal evoked potentials in multiple sclerosis prognostication

The ability to predict disability development in multiple sclerosis (MS) is limited. While abnormalities of evoked potentials (EP) have been associated with disability, the prognosticating utility of EP in MS remains to be fully elucidated. The present study assessed the utility of multimodal EP as a prognostic biomarker of disability in a cohort of clinically heterogeneous MS patients. Median and tibial nerve somatosensory, visual, and brainstem auditory EP were performed at initial assessment on 63 MS patients (53 relapsing–remitting and 10 secondary progressive) who were followed for an average of 2 years. A combined EP score (CEPS) was calculated consisting of the total number of abnormal EP tests, and was correlated with the Expanded Disability Status Scale (EDSS) at baseline and follow-up. There was a significant correlation between multimodal EP and baseline and follow-up EDSS. Specifically, tibial nerve P37 latencies correlated with EDSS (R_BASELINE = 0.49, p < 0.01; R_FOLLOW-UP = 0.47, p < 0.01), as did the median nerve N13 (R_BASELINE = 0.40, p < 0.01; R_FOLLOW-UP = 0.35, p < 0.05) and N20 latencies (R_BASELINE = 0.43, p < 0.01; R_FOLLOW-UP = 0.47, p < 0.01), and P100 full-field (R_BASELINE = 0.50, p < 0.001; R_FOLLOW-UP = 0.45, p < 0.001) and central field latencies (R_BASELINE = 0.60, p < 0.001; R_FOLLOW-UP = 0.50, p < 0.001). In addition, there was a significant correlation between the CEPS with baseline (R = 0.65, p < 0.001) and follow-up (R = 0.57, p < 0.01) EDSS. In contrast, white matter disease burden, as measured by T2 lesion load, exhibited a weaker correlation with EDSS (R_BASELINE = 0.28, p < 0.05). In conclusion, these findings suggest that abnormalities of EP, as quantified by the novel CEPS, may be a useful biomarker for prognosticating clinical disability in MS, and may aid in the quantification of MS disease severity and in guiding therapeutic decisions.     

Histopathology and serial, multimodal magnetic resonance imaging in a multiple sclerosis variant

Defining tools in magnetic resonance imaging (MRI) representing specific pathological processes is needed to understand the complex relationship between inflammation, myelin breakdown, axonal injury and clinical symptoms in multiple sclerosis (MS) and its variants. Here, we describe a case of histologically-defined MS, in which the radiological appearance of the lesion and clinical course support the diagnosis of Balo's concentric sclerosis. Serial magnetization transfer, diffusion tensor imaging and 1H-magnetic resonance spectroscopy, from 14 days to 13 months after biopsy, allow the contextual interpretation of specific pathological changes. In our case, acute inflammation was sensitively traced by fractional anisotropy and increased lactate in spectroscopy. In contrast, magnetization transfer ratio and the apparent diffusion coefficient monitor the sequential loss of tissue in selected rings of the lesion. The delay from the peak of symptoms in a dramatic clinical course to the maximum tissue destruction indicated through MRI suggests that compromise of axonal function may be decisive for the acute clinical situation. This is the first report comparing 1H-magnetic resonance spectroscopy, magnetization transfer and diffusion tensor imaging with histopathology in a patient with Balo's concentric sclerosis.     

Symptomatic retrochiasmal lesions in multiple sclerosis: clinical features, visual evoked potentials, and magnetic resonance imaging.

We have studied 18 patients with relapsing-remitting multiple sclerosis (MS) who had symptomatic visual field defects due to retrochiasmal lesions. In 17, the lesion responsible was identified by magnetic resonance imaging (MRI), computed x-ray tomography (CT), or both. The lesion responsible involved the posterior optic radiations in eight cases, the optic tract and lateral geniculate nucleus in six, and the posterior limb of the internal capsule in three. The prognosis for recovery of the field defect was good; complete recovery occurred in 14 patients, and only two showed no recovery at all. The striking characteristic of the lesions was that most were unusually large; indeed, many were detectable on CT as well as MRI. Half-field asymmetries of either amplitude or latency of the visual evoked potentials (VEPs), consistent with a postchiasmal lesion, were present in only five out of 13 patients acutely. In only three of these did the abnormality persist at follow-up. We conclude that only large postchiasmal lesions are likely to cause symptomatic homonymous field defects in MS, usually characterized by rapid recovery. Hemifield VEPs have a low sensitivity for the detection of postchiasmal as compared with prechiasmal abnormalities.     

Retrochiasmatic lesions in multiple sclerosis. Demonstration by visual evoked potentials. Correlation with magnetic resonance imaging

Monocular stimulation of each visual hemifield can show an interhemispheric asymmetry of VEP. Validity of this test needs a reproducibility of responses and exclusion of stimulation induced by eye movements. In a prospective study of 22 MS cases, it appeared that interhemispheric asymmetry was a criterion of dissemination is space and had a good diagnostic value: MS became clinically definite in 10/12 cases; in 10 other cases in which a correlative MRI-VEP study was possible, there were disseminated high signal areas in T2 weighted sequences on hemispheric MRI. In 7/10 cases, these areas were located on retrochiasmatic visual pathways. With MRI, VEP are the most performant tests for early diagnosis in MS. Technical progress will improve its fiability. Prospective correlative clinical, electrophysiological and MRI studies are necessary on a larger number of MS patients.     

Brainstem impairment in multiple sclerosis: an assessment by multimodal evoked potentials

The usefulness of multimodal evoked potentials for the diagnosis of Multiple Sclerosis (MS) is established. Our purpose was to try a set of 3 EPs (BAEP, median SEP and trigeminal SEP) in the evaluation of brainstem dysfunction. 53 definite and probable MS patients have been examined; they were allotted to 3 groups according to the duration of the disease. Our results showed that median SEP is the most sensitive investigation, while BAEP and trigeminal SEP were abnormal in a smaller number of cases. The combined use of median and trigeminal SEPs supplied sufficient information on brainstem function, without using the complete set of EPs. No significant relation between EP abnormalities and duration of the disease was found.

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Sommario Scopo della nostra ricerca è la valutazione dell'efficacia di una batteria di Potenziali Evocati (BAEP, PES mediano e PES trigeminale) nell'evidenziare alterazioni del troncoencefalo nel corso di Sclerosi Multipla. Abbiamo esaminato 53 pazienti con SM definita o probabile, suddivisi in tre gruppi in base alla durata di malattia (<2 anni, >2<10 anni, >10 anni). I nostri risultati mostrano che il PES mediano risulta la metodica più sensibile, mentre il BAEP ed il PES trigeminale sono anormali in un minor numero di casi. L'uso combinato dei PES mediano e trigeminale consente di ottenere buone informazioni sulla funzione troncoencefalica senza dover ricorrere necessariamente alla intera batteria di esami. Non è stata riscontrata alcuna correlazione significativa tra anomalie dei Potenziali Evocati e durata di malattia.

     

Brain-stem auditory evoked potentials (BAEPs) and magnetic resonance imaging (MRI) in a case of facial myokymia

The case of a 37-year-old woman with facial myokymia is reported. Magnetic resonance imaging (MRI), electromyography (EMG) and brain-stem auditory evoked potentials (BAEPs) supported the clinical diagnosis of suspected multiple sclerosis (MS). MRI showed a single area of abnormal signal in the pontine region. The authors discuss the possible relationship between the brain-stem lesion and the electrophysiological abnormalities demonstrated by BAEPs and the EMG of facial muscles.     

Detection of brainstem lesions in multiple sclerosis: comparison of brainstem auditory evoked potentials with nuclear magnetic resonance imaging

Topographical information provided by brainstem auditory evoked potentials (BAEPs) was investigated in 43 patients by comparison with cerebral nuclear magnetic resonance imaging (NMR). Lesions in the region of the brainstem auditory pathways were demonstrated by BAEPs in 44.2%, and in 39.5% by NMR. As regards brainstem levels, in 15/21 (71.4%) with abnormal findings at least one lesion was verified by NMR-matched BAEP results. The study confirms the topographical information provided by the BAEPs on the different levels of the brainstem, but not the assumption that generation of the BAEPs is predominantly ipsilateral. BAEPs retain their importance for the detection of disseminated lesions in the diagnosis of multiple sclerosis (MS) in the era of expensive imaging methods.     

Reduced visual evoked responses in multiple sclerosis patients with optic neuritis: comparison of functional magnetic resonance imaging and visual evoked potentials.

The limited application of functional magnetic resonance imaging (fMRI) for investigations of multiple sclerosis (MS) patients has already shown that deficits of the motor, cognitive and visual systems may be identified by differences in the patterns of activation in response to a suitable stimulus. In MS patients with unilateral optic neuritis, the area of activation in the primary visual cortex, measured by fMRI techniques, is dramatically reduced in response to stimulation of the affected eye. The latency of the major positive component of the visual evoked potential (VEP) recorded upon stimulation of the affected eye is significantly increased in these patients, as compared to the unaffected eye and normal volunteers. We have found a correlation between the neural response measured using fMRI and the latency of the VEP. fMRI signal responses have the potential to provide more detailed topographic information relating to functional deficits in MS.     

Clinical and instrumental (magnetic resonance imaging [MRI] and multimodal evoked potentials) follow-up of brain lesions in three young patients with neurofibromatosis 1

Diagnosis of neurofibromatosis 1 is based on clinical criteria. In a large number of children with neurofibromatosis 1, magnetic resonance imaging (MRI) reveals high-signal T(2)-weighted intensities in different brain regions, defined as unidentified bright objects. These lesions are asymptomatic; most of them regress spontaneously with age, but the presence of contrast enhancement or mass effect in them usually strongly suggests an increased risk of proliferative changes. To date, few studies have focused on evoked potentials in patients with neurofibromatosis 1, and the reported abnormalities did not have significant clinical correlations. We describe the clinical and instrumental (MRI and evoked potentials) follow-up of three patients with neurofibromatosis 1. MRI and evoked potentials showed subclinical involvement of the central nervous system. Some MRI T(2)-weighted hyperintensities showed enhancement and mass effect of uncertain significance. During follow-up, the MRI lesions spontaneously decreased in size or enhancement, allowing us to exclude the hypothesis of proliferative lesions; in the same way, some asymptomatic evoked potential abnormalities disappeared. These findings suggest that both MRI and evoked potentials could be useful in the detection and monitoring of cerebral complications of neurofibromatosis 1.