The value of brain stem auditory, visual and somatosensory evoked potentials and blink reflexes in the diagnosis of multiple sclerosis

Cervical and cortical somatosensory evoked potentials (SEP) following electrical stimulation of the median nerve and blink reflexes (BR) following electrical stimulation of the supraorbital nerve were recorded in 30 normal subjects aged 20–49 years. Subjects aged 40–49 had longer SEP latencies than subjects aged 20–39 years.
A total of 29 slightly affected patients with multiple sclerosis (MS) aged 26–49 years, including four patients without clinical signs (suspected MS) and 19 patients with signs indicating only one lesion (possible MS) were examined by low-rate random-stimulated brain stem auditory (BAEP), checkerboard pattern-reversal visual evoked potentials (VEP), SEP and BR. Abnormal recordings by at least one of the examinations were found in all but three patients, and by all four tests in five patients.
In patients with definite or probable MS, demonstration of clinically recognized or subclinical lesions was of minor diagnostic value, in contrast to the importance such findings had in patients with suspected or possible MS. Silent lesions were shown by at least one of the tests in the four suspected and in 13 of the possible MS patients, so these 17 patients could be transferred to a more certain diagnostic category. This reclassification was most often due to the BAEP recording.
In patients with spinal signs, the combination of BAEP and VEP recording was sufficiently efficient. In patients with optic neuritis a combination of BAEP and SEP was preferred. No abnormal recordings were found in 15 normal subjects examined by all four tests.     

Brain stem auditory and visual evoked potentials in multiple sclerosis

The diagnostic value of the checkerboard pattern-reversal visual evoked potential (VEP) and the random, low rate stimulated brain stem auditory evoked potential (BAEP) was compared in 99 patients with established or suspected multiple sclerosis (MS). In normal subjects examined by both techniques no abnormal recordings were found. In 49 patients with definite MS an incidence of abnormality was found in 100% of VEP and in 84% of BAEP recordings. In 50 patients with probable or possible MS an abnormal VEP was found in 70% and an abnormal BAEP in 50%. When the two examinations were combined, the diagnostic yield increased to 100 and 80%, respectively. 22 patients had only spinal symptoms; in these the VEP gave 73%, the BAEP 55% and the combination 82% abnormalities. The combination of the two techniques was found useful for demonstrating demyelinating lesions in the central nervous system, the diagnostic value being greatest when these lesions were clinically silent.     

Visual, early auditory and somatosensory evoked potentials in multiple sclerosis (917 cases)

Visual (VEP), brainstem auditory (BAEP) and somatosensory (SEP) evoked potentials were recorded over a 6 year period in 917 patients with or suspected of multiple sclerosis according to Mc Alpine's criteria. Evoked potentials provided information of diagnostic relevance in detecting clinically unsuspected lesions (spatial dissemination). They also gave valuable informations in patients with atypical or borderline clinical features. When abnormal, VEP indicated clinically silent lesions in 45.1 p. 100 of patients with definite MS, 66 p. 100 of those with probable MS and 78 p. 100 of the possible MS. Less than 15 p. 100 of SEP and/or BAEP abnormalities were found in 83 patients with a simple or recurring retrobulbar optic neuritis. Thirteen patients with acute transverse myelopathy and no prior history of neurological disease were studied. All had normal visual and brainstem auditory evoked potentials. Abnormal VEPs helped to the clinical assessment of 88 patients with progressive spastic paraparesis 46,6 p. 100 of whom had abnormal VEPs demonstrating disseminated lesions and 36,1 p. 100 had abnormal BAEPs. The frequency of the various types of VEP, BAEP and SEP abnormalities was studied as well as their course on repeated recordings. Results of multivariate analysis are given. It was found that the longer the time interval between the first MS relapse and the evoked potential recording, the higher the incidence of abnormalities. The incidence of evoked potentials abnormalities was lower in patients with normal CSF and higher in patients with inflammatory CSF. The abnormalities were more frequent when patients had clinical evidence of lesions of the sensory pathways explored by the tests.     

Brain-stem auditory evoked potentials in multiple sclerosis: the relation to VEP,SEP and CSF immunoglobulins

Summary One hundred patients with multiple sclerosis (MS) were analysed retrospectively with respect to investigations of brain-stem auditory evoked potentials (BAEP), pattern reversal visual evoked potentials (VEP), somatosensory evoked potentials (SEP), and cerebrospinal fluid immunoglobulins (CSF-IG). BAEP were abnormal in 42% of those with normal VEP and SEP examinations, and in 38% of patients with normal CSF-IG. The chance of obtaining at least one abnormal EP was lower in patients with normal CSF-IG than in patients with abnormal CSF. When a dispersion ratio was included in the criteria for BAEP abnormality, the sensitivity increased compared with conventional BAEP criteria. We recommend that BAEP should still be included in the EP test battery for patients with suspected MS.     

Success and failure of evoked potentials in detecting clinical and subclinical lesions in multiple sclerosis patients

The value of visual, brain stem auditory and somatosensory potentials in detecting clinical and subclinical lesions as compared to the routine neurological, ophthalmological and vestibular examinations was investigated in 100 M.S. patients. It would appear that the VEP and SEP are far superior to the routine techniques in demonstrating lesions. On the other hand, the BAEP is inferior to the clinical and vestibular test as an indicator of brain stem lesions. All clinically manifest posterior column lesions are associated with abnormal SEP. However a substantial proportion of clinically evident lesions in the visual pathways or the midbrain and pons are not detectable by the VEP and BAEP.     

Evoked potentials and CSF-immunoglobulins in MS: relationship to disease duration, disability, and functional status

In 100 MS patients, BAEP and tibial SEP abnormality rates increased significantly with disease duration and clinical disability. VEP correlated non-linearly with disease duration, and median nerve SEP correlated with disability. In multifactorial analysis, however, BAEP correlated significantly only with clinical brainstem and cerebellar signs. These results suggest that evoked potentials correlate more strongly with neurological status of the functional subsystems than either overall disability or disease duration. These findings indirectly suggest that evoked potentials may be useful monitors during large therapeutical trials in MS patients.     

Short term neurophysiological monitoring in multiple sclerosis bouts. Evaluation of steroid treatment

Visual (VEP) and brainstem auditory (BAEP) evoked potentials (EP) were recorded in 21 multiple sclerosis (MS) patients in acute relapse before and after steroid treatment. VEPs were abnormal in 14/21 patients and BAEPs in 10/21 patients before treatment. In 4 patients with acute optic neuritis (ON), an improvement of VEPs paralleled clinical evolution in 3 cases. Substantial and contrasting changes in VEPs or BAEPs, with no clinical counterpart, were related to a spontaneous fluctuation of EPs in acute relapses of MS. These changes suggest frequent subclinical (multifocal and, possibly, sequential) central nervous system involvement in MS bouts. Group analysis showed nonsignificant changes in EP parameters before and after treatment. Our results indicate that evoked potentials (EPs) are of limited value for monitoring the short-term effect of steroid treatment in MS in bouts.

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Sommario I potenziali evocati visivi (VEP) ed acustici troncoencefalici (BAEP) sono stati eseguiti in 21 pazienti affentti da sclerosi multipla (SM) in fase di poussée, prima e dopo un ciclo di trattamento con steroidi. Prima del trattamento i VEP edi BAEP sono risultati alterati in 14 e 10 pazienti rispettivamente. 4 pazienti presentavano una neurite ottica (ON) in fase acuta; in 3, dopo il trattamento, è stato rilevato un significativo miglioramento dei VEP e dell'acuità visiva. Significative, ma contrastanti, modificazioni dei VEP e BAEP, riscontrate in altri 5 pazienti, non correlate all'evoluzione clinica, sono suggestive di un interessamento subclinico, multifocale e possibilmente sequenziale, durante una poussée della SM. L'analisi per gruppi non evidenzia differenze statistiche significative tra prima e dopo il trattamento. I nostri risultati indicano che i potenziali evocati sono di limitata utilità ai fini di un monitoraggio a breve termine della SM in poussée.

     

Visual and auditory evoked potentials in the early diagnosis and follow-up of neurosarcoidosis

Visual and brainstem auditory evoked potentials (VEPs, BAEPs) were recorded in 23 patients with neurosarcoidosis. Eight patients (35%) had abnormal BAEPs, and 10 (43%) had abnormal VEPs. Four of the 8 patients with abnormal BAEPs had facial paresis, one had impaired memory and only 3 had symptoms and signs compatible with brainstem lesion. Seven of the patients with abnormal VEPs had no visual symptoms. These findings suggest that BAEP and VEP can reveal subclinical nervous system involvement in sarcoidosis and can also help in the early diagnosis of neurosarcoidosis. Successive recordings of 5 patients showed that BAEP and VEP were useful in the follow-up of these patients.     

Variations of brain stem auditory evoked potentials correlated to duration and severity of multiple sclerosis

A total of 158 recordings of brain stem auditory evoked potentials (BAEPs) were obtained in 121 patients with multiple sclerosis. A statistically significant increased incidence of abnormality and diffusely abnormal recordings was found with increasing duration and severity of symptoms. Alterations in follow-up recordings might reflect changes in the clinical state, but also occurred in clinically stable patients. These findings suggested that transition from normality of BAEPs might occur either by successive disappearance of the later waves or by uniformly decreasing amplitudes of all the waves to diffusely abnormal recordings. It was concluded that the main value of BAEP recording in patients with multiple sclerosis was to indicate clinically silent lesions, and its value in monitoring the clinical condition of the individual patient was dubious.     

Electrophysiological detection of "silent" plaques in the optic pathways

The incidence of a delayed P100 component of the VEP after checkerboard stimulation in probable or possible multiple sclerosis (MS) without history, signs or symptoms of optic neuritis is not significantly different from that found in other neurological disorders in which the visual system is unaffected. This reduces the diagnostic validity of a delayed P100 as evidence of "silent" plaques in the optic pathway, at least in suspected MS. The use of grating increases the VEP sensitivity in the MS group, but it still leaves more than a 30% chance of error in attributing a delayed P100 to a demyelinating disorder. In this respect the discordant behaviour of checkerboard and grating responses may represent a useful clue.     

Neurophysiological and CSF immunological study of 19 patients affected by acute idiopatic optic neuritis

We studied 19 patients affected by acute idiopatic optic neuritis (ON), with neurophysiological tests: visual (VEP), somatosensory (SSEP), acoustic (ABR) evoked potentials and study of the blink reflex (BR), and with cerebrospinal fluid (CSF) examination, in order to detect "silent" lesions in the central nervous system (CNS) and/or immunological alterations, suggestive of multiple sclerosis (MS). The percentage of cases with at least one altered CSF IgG parameter (IgG index, IgG synthesis/day and IgG oligoclonal bands) has been higher than that of cases with one or more altered neurophysiological tests, regardless of the apparently intact eye VEP. If we also included this last test, the 2 percentages become identical. The validity of these tests in predicting the evolution of ON in MS is discussed.     

Evoked potentials in suspected multiple sclerosis: diagnostic value and prediction of clinical course

Pattern visual, somatosensory and brainstem auditory evoked potentials (EPs) of 14 patients with definite multiple sclerosis, 222 patients suspected of having multiple sclerosis, 26 patients with isolated optic neuritis and 40 patients with a chronic not diagnosed neurologic disorder, were compared with their clinical diagnoses on 2 1/2-year follow-up. In the MS suspects, an EP abnormality demonstrating a clinically silent lesion in any modality (65 patients) was associated with a 71% chance of clinical deterioration (48% chance of definite MS within the follow-up period). Normal EPs (121 patients) were associated with a 16% chance of deterioration (4% chance of definite MS). EPs in patients in whom the only abnormalities confirmed known lesions (36 patients) did not predict follow-up status. Visual EPs demonstrated clinically silent lesions more frequently than somatosensory and auditory EPs (22%, 12% and 5% of patients). Only one of the patients with optic neuritis and 3 of the chronic not diagnosed group had EPs demonstrating clinically silent lesions. CSF and NMR studies also correlated with follow-up in subseries of the patients.     

Subclinical visual field defects in multiple sclerosis

Summary Fourteen patients with definite but inactive multiple sclerosis (MS) and 17 normal controls were examined with the automated perimeter octopus. Most of the patients had subclinical visual field defects, typically consisting of patchy, shallow scotomata located mostly in an area of between 15° and 30° eccentricity. In 8 patients, more than 15% of the tested visual field of at least one eye was abnormal. The severity and extent of the defects was unrelated to a history of optic neuritis. When visually evoked potentials (VEPs) of these subjects were examined using a reversing pattern, no correlation was found in the MS patients between prolonged VEP latencies and the location, depth or extent of visual field defects. Since subclinical visual field defects may be found in MS patients with normal VEP latencies, automated perimetry can be helpful in diagnosing some cases.Supported in part by Geigy Jubilaeumsstiftung, Basel     

Multimodal evoked potentials in neuro-Behçet: a longitudinal study of two cases

Two neuro-Behçet patients have been studied, over a period of several months, by means of peroneal and median somatosensory- (SEP), brainstem auditory- (BAEP), and visual- (VEP) evoked potentials. In both patients, peroneal SEP showed evidence of a pathological reduction in the central conduction velocity without a related deep sensation impairment, while VEP changes were consistent with the visual disorders. Conversely, BAEP and median SEP findings did not show disease-related abnormalities. The observed anomalies were detectable irrespective of the clinical phase of the disease. Thus, evoked potential assessment is useful in providing objective evidence for evaluating and monitoring CNS damage in neuro-Behçet's syndrome.     

DM基因CTG重复数与BAEP、SEP、VEP对比分析

目的：探讨强直性肌营养不良（DM）患者及其家系成员三核苷酸重复数CTG（胞嘧啶、胸腺嘧啶、乌嘌呤）的变化与脑干听觉诱发电位（BAEP）、体感诱发电位（SEP）、视觉诱发电位（VEP）的关系。方法：用聚合酶链（PCR）扩增及DNA杂交法对5例临床诊断DM患者及其中三个家系的16名成员进行DM基因的CTG重复数和BAE、SEP和VEP测定。结果：10名正常人CTG重复数是30个，BAEP、SEP、VEP正常；5例DM病人CTG重复数均在85个以上，其中2列在1605个以上，明显高于正常人；16例家系成员中除4例正常，余12例CTG重复数均超过正常基因，而且，CTG重复数与临床症状、BAEP、SEP、VEP轻重有关。结论DM基因诊断有其临床症状、BAEP、SEP、VEP改变相一致。     

The use of evoked potentials in the management of patients with severe cerebral trauma

Evoked potentials (SEP and BAEP) were measured daily in 18 patients who had suffered severe craniocerebral trauma, but could not be examined neurologically due to a barbiturate coma or neuromuscular blockade. The BAEP had only limited value as an indicator of the prognosis for these patients. The N20 component of the SEP appeared to be more valuable in this respect. Serial registration of the EPs was also of prognostic significance and proved to play an important role in the decision to stop or continue the barbiturate coma. In some patients serial measurement of the EPs also gave an indication of the presence of late posttraumatic intracranial mass lesions. EPs are useful for the monitoring of cerebral functions in patients who have suffered a contusion of the brain and can no longer be assessed clinically.     

Large check size pattern reversal visual evoked potentials – Full and sectorial field stimulation in multiple sclerosis and controls

Pattern reversal visual evoked potentials have been used to study optic neuritis. Although smaller check size in the central fields are more sensitive, larger check sizes can be advantageous for patient fixation and in poor vision. We compared sectorial central and peripheral hemisurround stimulus with commonly used full- and half- field stimulus using large check sizes (65′) in the context of optic neuritis and multiple sclerosis. Of 19 female and 16 male control subjects studied, females had shorter P100 latencies and larger amplitudes than males. In 9 of the 18 patients with VEP abnormalities, the central field abnormalities were greater than those recorded with the full field response. The results confirm for the first time that central field stimulation using large checks can show a greater extent of abnormality than can be appreciated with large check full field stimulation alone, and could be commonly employed to improve yield in the investigation of optic neuritis. The data suggest that it is necessary to collect separate gender-specific laboratory normal values using this check size.     

卡马西平对诱发电位的影响及意义

目的研究长期口服卡马西平治疗癫对诱发电位的影响,并讨论其意义。方法选择尚未治疗的癫病人31例作为试验组;以性别、年龄与癫组相匹配的健康正常人26例作为对照组。两组先分别做脑干听觉诱发电位(BAEP)、事件相关电位P300、视觉诱发电位(VEP)和体感诱发电位(SEP),之后癫组开始卡马西平治疗,服药一年后再作上述各项检查。结果癫组病人治疗前各项电生理学指标与正常对照组相比无显著性差异;癫组卡马西平治疗后各项电生理指标与治疗前相比BAEP各波、P300以及VEP的P100波潜伏期均显著延长;SEP的潜伏期无显著变化。结论神经电生理学检查可以早期发现长期服用卡马西平导致的亚临床毒性。     

MRI, VEP, SEP and biothesiometry suggest monosymptomatic acute optic neuritis to be a first manifestation of multiple sclerosis

A cohort of 50 consecutive patients with acute monosymptomatic optic neuritis (ON) from a defined catchment area joined a prospective study. The aim of this study was to compare the sensitivity of magnetic resonance imaging (MRI), electrophysiological methods (VEP and SEP) and biothesiometry to detect abnormalities in other parts of the CNS than the optic nerves during the acute phase of ON. For each method, a scoring system is proposed. This investigation also hoped to achieve a better understanding of the natural history of ON. MRI proved to be the most sensitive tool (63% abnormal) in confirming a second site of involvement, followed by VEP in the clinically unaffected fellow eye (42%), biothesiometry (32%) and SEP (17%). The combination of all these methods, except for MRI (and VEP in eyes with acute ON), revealed abnormalities in 63% of the patients. When the neurophysiological methods were combined with MRI, 79% of the patients had abnormal findings suggesting additional lesions in the CNS. Hence, MRI and neurophysiological examinations supplement each other and together provide evidence that monosymptomatic ON is usually a first manifestation of MS. The development of definite MS at 1-20 months of follow up in 7 patients (all with abnormal MRI initially) supports this view.     

A study of clinical, MRI and multimodality evoked potentials in neurologic Wilson disease

The aims of this study were evaluate motor, somatosensory, visual and auditory brainstem evoked potential (MEP, SEP, VEP, ABER) changes in Wilson disease (WD) and correlate these with magnetic resonance imaging (MRI) and clinical findings.
Neurologic WD diagnosed on the basis of clinical, ceruloplasmin and Kayser–Fleischer ring were evaluated including pedigree charting, hepatic, renal, hematologic and osteoarticular manifestations. Blood counts, serum chemistry, MRI, MEP to tibialis anterior, tibial SEP, VEP and ABER were performed. Evoked potential (EP) changes were correlated with clinical and MRI findings.
Eighteen WD patients were recruited from 17 families whose mean age was 16 years. Movement disorders were present in 14, cognitive decline in 12 and pyramidal signs in 12 patients. MRI revealed involvement of basal ganglia in 80%, thalamus in 40%, brain stem in 46.7% and subcortical white matter in 53.3%. MEP was abnormal in 35.7%, SEP in 30.8%, VEP in 57% and ABER in 61.5% patients; the latter three EP changes were subclinical. Frequency and number of EP abnormalities were higher with increasing severity of illness.
SEP, VEP and ABER reveals subclinical abnormality and MEP helps in documenting both clinical and subclinical abnormalities. Number of EP abnormalities increases with increasing clinical severity of WD.