Visual and somatosensory evoked cortical potentials in multiple sclerosis.

The diagnostic value of the pattern reversal evoked cortical potential (VEP) and the somatosensory evoked cortical potential (SEP) has been compared in 50 patients with established or suspected multiple sclerosis. A prolonged latency of VEP was found in 96% of definite cases of multiple sclerosis, 58% of probable cases, and 20% of possible cases. A prolonged latency of SEP by stimulation of median or peroneal nerves or both was found in 86% of definite cases of multiple sclerosis, 83% of probable cases, and 50% of possibe cases. When combining the results of all three tests the diagnostic yield increased to 100%, 92%, and 50%, respectively.     

Pudendal nerve somatosensory evoked potentials in probable multiple sclerosis

Bladder dysfunctions are often observed in patients with multiple sclerosis (MS). In order to evaluate their sensitivity in detecting abnormalities in bladder central control pathways, pudendal nerve somatosensory evoked potentials (pSEPs) were recorded in 16 patients with clinically probable MS: six were affected by retention or urge incontinence, and ten were asymptomatic. Conventional visual, auditory and somatosensory evoked potentials were also recorded, and all of the patients underwent a urodynamic examination. Prolonged latency or the absence of pSEP cortical responses was found in eight of the ten asymptomatic patients, and in all of the symptomatic cases (87.5%). The urodynamic evaluation revealed abnormalities in 12 patients (75%). Our findings seem to indicate an early and frequent involvement of bladder control pathways in MS patients, as well as a high rate of subclinical disorders.This work was supported by grants from MURST, Italy     

Correlation of somatosensory evoked potentials and long loop reflexes in patients with multiple sclerosis

Based on the results of somatosensory evoked potentials (SEPs) and long loop reflexes (LLRs) obtained from the 50 upper limbs of 25 normal controls by stimulating the median nerve, four regions were set up in a latency correlation diagram between N20 and LLR, which were assumed to mainly represent the afferent and the efferent functions, respectively. Seventy upper limbs of patients with multiple sclerosis, differently marked according to the presence or absence of pyramidal sign and/or impaired vibration sense, were plotted on the diagram. The regions to which the patient belonged turned out to be reasonably compatible with the neurological status of the patient. Simultaneous measurements of SEPs and LLRs are therefore useful to evaluate the afferent and efferent pathways in the central nervous system.     

Clinical correlations of serial somatosensory evoked potentials in multiple sclerosis

Serial median nerve somatosensory evoked potentials (SEPs) were recorded in 12 patients with definite MS. On the initial tests, there was no clear association between the severity of clinical disease activity and SEP findings. The cervical response was most frequently affected and, when present, was often abnormal in configuration, suggesting absence or delay in the far field P14 component with preservation of cervical N11 and N13 components. Clinical motor and sensory findings in the corresponding limb frequently correlated with abnormalities of the cervical response. When new motor and sensory findings developed in the arms during the study, the SEP deteriorated in some patients but improved in others. Most SEP changes were not accompanied by clinical changes. Overall disability sometimes increased during the study despite improvements in the SEP.     

Trigeminal somatosensory evoked potentials in multiple sclerosis: a case report.

Somatosensory evoked potentials elicited by trigeminal nerve stimulation (TSEPs) allow the study of the trigeminal system, its peripheral to its central portion. As a routine clinical testing procedure, however, this method has not yet received greater attention and still has to wait to become a part of the diagnostic workup in multiple sclerosis (MS). A patient diagnosed as MS was presented with selective involvement of the left trigeminal nerve. Neurophysiologically, the most prominent and persistent abnormalities were found in the TSEPs. The presumed diagnosis of MS was subsequently confirmed by MRI showing evidence of demyelinating disease. There has been a scarcity of references on TSEP. Our study emphasizes its usefulness and a plea is being made for the inclusion of TSEP in protocols for the diagnostic workup in patients with MS.     

Effect of raising body temperature on visual and somatosensory evoked potentials in patients with multiple sclerosis.

The effects of raising body temperature on the visual (VEP) and somatosensory (SEP) evoked potentials were observed in normal subjects and in patients with multiple sclerosis. The amplitude of the VEP was significantly reduced to the same degree after heating in normal subjects and in patients with multiple sclerosis but there was no effect on the latency of the potential. Changes in amplitude could not be related to reduction in acuity. In contrast, the cervical SEP was greatly disorganised after heating in many patients with multiple sclerosis while the only effect in normal subjects was to reduce the latency by increasing peripheral conduction velocity. These results suggest that heat caused conduction block in demyelinated axons in the sensory pathways of the cervical spinal cord.     

Magnetic stimulation motor evoked potential in multiple sclerosis. Comparison with visual evoked potentials, brain stem auditory evoked potentials and somatosensory evoked potentials]

This study consists of 45 patients with clinically definite MS, laboratory supported definite MS and clinically probable MS. We compared MEP results with other multimodal evoked potentials (VEP, BAEP and SEP). The abnormal rate of MEP was 87.6%, which was the highest. Abnormal MEP showed prolonged central motor conduction time (CMCT), consistent with pathological change of the demyelination. There was a evident correlation between the abnormal MEP and VEP, which is consistent with the most common MS (Devic Syndrome) in our country.     

Vestibular evoked myogenic potentials in multiple sclerosis patients.

OBJECTIVES: Vestibular evoked myogenic potentials (VEMPs) are saccular responses to loud acoustic stimuli and are recordable from the sterno-cleido-mastoid muscle ipsilaterally to the stimulated ear. This study aimed to investigate VEMPs in patients suffering from multiple sclerosis (MS), and to compare these findings with both clinical and instrumental data. METHODS: We recorded VEMPs from 70 MS patients, whose clinical data were retrospectively evaluated for the possible occurrence of: past and current (with respect to VEMP recording) brainstem and/or cerebellar symptoms; current brainstem and/or cerebellar signs. Sixty-five patients underwent brainstem auditory evoked potentials (BAEPs) recording; 63 of the same patients underwent saccadic eye movement recording and subjective visual vertical (SVV) evaluation. RESULTS: VEMPs were abnormal in 31%, BAEPs in 38% and SVV in 21% of the patients. Saccadic eye movements showed a possible brainstem dysfunction in 44.4% of the patients. There was no correlation between the occurrence of abnormalities and the technical means of detection. The same held true for correlations with clinical data, with the exception of the BAEPs; these proved to be more frequently abnormal in patients presenting at neurological examination with brainstem and/or cerebellar signs that were possibly related to the complaint of dizziness. CONCLUSIONS: VEMPs should be considered a useful complementary neurophysiological tool for the evaluation of brainstem dysfunction.     

Lumbosacral spinal evoked potentials in patients with multiple sclerosis

Lumbosacral spinal evoked potentials were recorded percutaneously in 22 MS patients with spinal symptoms and in 24 age-matched normal volunteers. Latencies, durations, and areas of waves R and A (level S1) as well as S and P2 (level Th12) were analyzed. The most significant result observed in the MS group was a reduction of the ratio between the areas of P2 and S. The reduction was strongly correlated with intensity of spasticity, but not with other clinical features. The P2/S ratio can thus be proposed as an electrophysiologic measure of spasticity.     

EDSS correlated analysis of median nerve somatosensory evoked potentials in multiple sclerosis

Median nerve somatosensory evoked potentials (SEP) were recorded in 30 patients with multiple sclerosis. The examined patients had an expanded disability status scale (EDSS) between 0 and 6. The primary cortical potential N20, the subcortical potentials P14, N13b, N13a and the peripheral potential P9 were recorded simultaneously. In 5 patients normal SEP were observed (group 1) and in 6 patients there were consecutive disturbances of the somatosensory pathway (group 3). In 19 patients subcortical potentials were abnormal or absent while the following potentials were normal or identified which pattern corresponds to amplification within CNS structures (group 2). The EDSS of groups 1 and 2 were similar and lower than the EDSS of group 3, which indicates that amplification mechanisms could represent a positive prognostic factor in SEP diagnosis of multiple sclerosis. Received: 15 March 2000 / Accepted in revised form: 4 September 2000     

肌萎缩性侧索硬化症患者体感诱发电位研究

目的 研究肌萎缩性侧索硬化症(ALS)患者体感诱发电位(SEP)变化。方法 采用正中神经及肠后神经体感诱发电位(mSEP、tSEP)对30例患者进行检测，并与27例健康人作对比。结果 mSEP和tSEP的异常率分别为43．3％(13／30)及28％(7/5)，除N9、PF(腘点)、LP(T12点)峰潜伏期和对照组相比无显著差异外，其余各峰潜伏期及峰间期和对照组相比均有显著性差异。结论 ALS患者存在感觉通路损害，且中枢的改变较周围更明显，SEP检查对患者感觉损害的定位有一定价值。     

Usefulness of trigeminal somatosensory evoked potentials to detect subclinical trigeminal impairment in multiple sclerosis patients

Trigeminal somatosensory evoked potentials (TSEPs) by surface electric pulse stimulation were recorded in 30 normal subjects and in 70 multiple sclerosis (MS) patients, 13 of whom presenting clinical trigeminal impairment. We observed significant prolongation of all TSEPs parameters in MS group. TSEPs were abnormal in 45 patients (64.3%). Clinical and neurophysiological data agreed in 36 patients (51%) on 84 sides (60%). TSEPs were able to detect clinically silent lesions 54 times. TSEPs recording proves to be an additional useful test in MS multimodal evoked potential protocols.     

Pattern reversal visual evoked potentials in Japanese patients with multiple sclerosis.

Forty-seven Japanese patients with multiple sclerosis, 29 probable (clinically definite) and 18 possible, were studied by black-and-white checkerboard pattern reversal visual evoked potential and were compared with a control group of 20 healthy young adults. The major positive peak (P100) was found to be abnormal in 70% of all cases, 90% of probable cases and 39% of possible cases. P100 was delayed in 38% of all cases and was absent in 23% of all cases. None of the eyes showing a flat pattern response was in the acute stage of optic neuritis. The percentage of cases with no response (23% of all cases) was greater than any of the previously reported series from Western countries, substantiating the previously reported clinical features of oriental multiple sclerosis. The pattern response was absent only when testing eyes with severe visual impairment, whereas delayed latency of P100 was seen regardless of the severity of visual impairment, suggesting the usefulness of P100 latency for detecting subclinical optic nerve lesions.     

Sensitivity of eye movement registration and visual evoked potentials in evaluation of therapy in patients with multiple sclerosis.

A major problem in the evaluation of multiple sclerosis (MS) treatment protocols is the lack of an objective and reliable marker of disease activity. In 24 MS patients who were treated with high doses of intravenous methylprednisolone because of an acute relapse or progressive disease the clinical improvement (as measured by the Kurtzke expanded disability status scale) was compared with two paraclinical parameters, i.e. visual evoked potentials (VEP) and the registration of saccadic and smooth pursuit eye movements. After treatment a significant clinical improvement was found in 50% of the patients. The registration of eye movements revealed a significant improvement in 83% of the patients, the VEP in 21%. It is demonstrated that especially the registration of eye movements can have an important application as an objective and sensitive method in the assessment of neurological functions during MS treatment protocols.     

Abnormal somatosensory evoked potentials in amyotrophic lateral sclerosis

A patient with typical clinical and electromyographic features of amyotrophic lateral sclerosis (ALS) was found to have abnormal somatosensory evoked potentials (SEPs). Evoked responses are generally considered to be normal in ALS despite occasional pathological and clinical evidence of sensory involvement. Thus, abnormal SEPs are considered to argue against a diagnosis of ALS. Based on the present case and a review of the literature, we suggest that abnormal SEPs need not exclude a diagnosis of ALS.     

多发性硬化伴可能周围神经病变的神经传导速度观察

自1904年Denkler首次报道1例多发性硬化(MS)尸检中发现有周围神经脱髓鞘病损[1]以来,MS伴随周围神经病变越来越引起研究者的注意。近年有学者提出,自身免疫病的各种临床表现可能是由免疫调节障碍引起多个靶器官受累导致,并不一定是合并多种疾病[2],周围神经系统(peripheral nervous system,PNS)与中枢神经系统(central     

多发性硬化的诱发电位特点

目的分析多发性硬化(multiple sclerosis,MS)模式翻转视觉诱发电位(pattern reversal evoked po-tential,PRVEP)、脑干听觉诱发电位(brainstem auditory evoked potential,BAEP)和体感诱发电位(somatosenso-ry evoked potential,SEP)等三种诱发电位(evoked potential,EP)的临床特点。方法对83例确诊MS患者进行回顾性分析,根据有无相应临床症状、病程及功能残障程度对EP进行分层研究,探讨其变化规律。结果三种EP的异常率在有临床症状组〔PRVEP、BAEP及下肢短潜伏期体感诱发电位(SLSEP)异常率分别为88.00%、66.67%、100%〕与无临床症状组(PRVEP、BAEP及下肢SLSEP异常率分别为60.61%、31.71%、79.63%)间比较均存在统计学差异(均P<0.05)。PRVEP的峰潜伏期(PL)延长及侧间峰潜伏期差值(ILD)增加的异常率之和与病程呈正相关(r=1.0,P<0.05);病程在20年以内时BAEP异常率与病程呈正相关(r=1.0,P<0.05);SLSEP下肢未引出率与病程呈正相关(r=1.0,P<0.05)。PRVEP异常率与EDSS分值呈正相关(r=1.7,P<0.01);SLSEP上肢异常率及下肢未引出率也与EDSS分值呈正相关(分别r=1.8,P<0.01;r=1.6,P<0.01)。结论三种EP的异常率与有无相应临床症状相关,且与病程及功能残障程度在一定范围内呈正相关。     

Cerebral evoked potentials in multiple sclerosis

Multimodal evoked potentials were analyzed from 58 possible, 62 probable and 100 definite (total 220) multiple sclerosis (MS) patients. Visual evoked potentials (VEP) were most frequently abnormal yielding 39%, 69%, 84% in the three diagnostic groups respectively. Median nerve sensory evoked potentials (SEP) yielded abnormalities in 26%, 65%, 79% respectively. Brainstem auditory evoked responses (BAER) were abnormal in 17%, 39%, 66% respectively. We measured the combined amplitude (CA) of waves III, IV, V in the BAER of these patients as an objective measure of amplitude asymmetry. The CA was considered abnormal if it was 1SD below the lowest CA value in the control group. The CA was abnormal in 9.2% of BAER with normal central conduction time. The BAER diagnostic yield in MS patients increased 11% by using CA analysis.     

Visual evoked potentials in normal subjects and patients with multiple sclerosis

Visual evoked potentials (VEPs) by checkerboard pattern-reversal stimulation were recorded in 70 subjects aged 10–69 years and in 100 patients with definite, probable or possible multiple sclerosis (MS). Longer latencies and smaller amplitudes of the major positive component were found in male subjects, in old subjects and when the amplifier's band-pass was narrowed. Subjects 10–14 years old had longer latencies and higher amplitudes than mature adults. Based on findings in the normal material, the following three criteria were used in evaluating the recordings from patients: the latency, the side difference in latencies and the ratio of amplitudes between the two sides of the major positive component with various limits for the two sexes and different age groups.
The incidence of abnormal recordings was 85% for all the patients, 100% in 50 patients with definite, 70% in 50 patients with probable or possible MS, 73% in patients who had a history of spinal symptoms only, 98% if they had and 74% if they had not experienced optic neuritis. The incidence of abnormal findings increased with increasing duration of symptoms. All patients with visual acuity below 0.67 had abnormal VEPs.
The high incidence of abnormal recordings confirmed the value of the test in establishing the diagnosis, and suggested that the use of different normative values for sex and age may increase the diagnostic yield without increasing the number of false positive findings.