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。     

Evoked potentials

ABSTRACT- A survey is given of my studies of evoked potentials in patients with multiple sclerosis (MS) and in control subjects. Potentials were recorded following random low-rate auditory stimulation (BAEP), checkerboard pattern-reversal stimulation (VEP), somatosensory stimulation (SEP); blink reflexes (BR) were recorded following electrical stimulation of the supraorbital nerve. Normal data had to be related to age and sex in evaluating BAEPs and VEPs.
In 160 MS patients, a total of 421 recordings were obtained. Changes by repeated BAEP and VEP tests might reflect changes in the clinical state, but they also did occur in clinically stable patients. In patients with definite MS, high incidences of abnormality were shown, supporting the clinical findings. The diagnostic value was greatest when clinically silent lesions were demonstrated in patients with suspected or possible MS. In these patients, either BAEP or VEP gave evidence of subclinical lesions in about 50%, and when combined, in 71% of the patients, thus making a transfer to a more certain diagnostic classification possible and invasive examinations unnecessary. When SEP and BR tests were added, subclinical lesions were found in 74% of the patients. The SEP recordings did show a high incidence of abnormality, but only few silent lesions; the BR test was the least sensitive. The VEP was abnormal in all patients with signs of optic neuritis and in all but one with a history of optic neuritis.
The present results are compared to those obtained in other laboratories and with other types of examinations in MS patients. It is concluded that although the tests are not specific for MS, they give valuable information in the majority of patients with a clinically uncertain diagnosis. This information will most often not be given by other types of examination. The combination of VEP and BAEP is recommended, but it should be supplemented by SEP recording in patients without spinal signs.     

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.     

诱发电位监测在显微外科手术治疗颅内动脉瘤中的初步应用

背景 近年来显微外科手术技巧取得很大的进步,然而颅内动脉瘤手术仍然存在众多并发症.多种术中特定手术操作造成的大脑功能区缺血与术后神经系统功能损伤有关.为进一步提高颅内动脉瘤手术的安全性、减少术后脑缺血性并发症的发生,有必要在术中对相应脑血管供血区域的缺血性损伤进行实时的监测.我们在颅内动脉瘤显微外科手术中联合应用运动诱发电位(MEPs)、体感诱发电位(SSEPs)及脑干听觉诱发电位(BAEPs)监测,提高术中诱发电位(EPs)信号改变对特定手术步骤导致脑缺血的敏感性,并研究它们与术后神经功能结果之间的关联性.方法 我们于2006年3月至2006年8月对我院25例采用显微手术的动脉瘤患者联合应用MEPs、SSEPs和BAEPs进行术中监测.对22例前循环动脉瘤手术,单纯行SSEPs监测4例,行MEPs及SSEPs监测18例,对3例后循环动脉瘤手术同时监测MEPs、SSEPs及BAEPs,将术中监测结果与术后神经功能作前瞻性观察研究.①SSEPs监测记录及刺激电极均采用皮下针电极.监测上肢SSEPs时,按国际脑电学会制定(10～20)系统,参考电极放在Fz,记录电极放在C3'、C4'和双侧Erb点,分别记录双侧皮质电位和外周电位.刺激电极放在腕部左右正中神经,刺激强度为15～25 mA,刺激间期0.2 ms,刺激频率3.1 Hz,波带通50～300 Hz,分析时间50 ms.监测下肢SSEPs时,记录电极置于Cz和双侧腘窝,分别记录双侧皮质电位和腘窝电位.刺激电极放在内踝部左右胫后神经,刺激强度为20～30 mA,记录参数与上肢SSEPs监测相同.术中主要观察手术侧皮质电位(上肢为N20波,下肢为P37波).所有波形均以麻醉后40 min SSEPs的值为标准,警报标准为波幅降低大于基线的50%或潜伏期延长10%.②MEPs监测采用外接电刺激器(Digitimer D 185 stimulator),刺激电极采用螺旋塞电极,记录电极采用皮下针电极.刺激电极放在C3/C4或C1/C2前1～2 cm,阴极放在对侧相应的地方.刺激采用恒流经颅连续短串电刺激5个单相方波,阳极刺激,持续时间300μs,刺激间隔2 ms(重复频率500 Hz),最大刺激电压600 V.记录从双侧肱二头肌、拇短展肌、胫前肌和拇展肌诱发的肌源性MEPs.警报标准为肌原性MEPs波幅消失.采用四联刺激肌肉收缩试验(TOF)监测神经肌肉反应活动.③BAEPs监测记录电极采用皮下针电极,置于两侧乳突.参考电极置于头顶(Cz).耳道插入式短声刺激.11.1 Hz疏密波,100 dBnHL级,对侧耳道60 dBnHL白噪音掩蔽.波带通30～1 500 Hz,分析时间15 ms,叠加1 000次.警报标准为V波潜伏期延长大于0.8 ms或波幅降低大于基线的50%.麻醉维持采用异丙芬、芬太尼、异氟醚、N2O和万可松,控制吸入性麻醉剂和肌松药的用量.结果 对载瘤动脉临时阻断、载瘤及临近重要血管的误夹、过度脑牵拉、血管痉挛或小穿支血管损害等术中事件引起的脑缺血,MEPs5/21、SSEPs5/25、BAEPs1/3出现异常.3例术后出现新的肢体运动功能障碍病人中,术中均有MEPs异常,而SSEPs仅1例异常.术中EPs未出现异常的病例,术后均未出现新的神经功能障碍.结论 通过本组初步研究,笔者认为MEPs监测对于运动系统缺血性损伤的敏感性优于SSEPs监测,术中EPs信号改变与术后神经功能结果之间具有良好的关联性,而稳定的EPs联合监测有助于预测健全的感觉运动功能,并且保证足够的远端侧支血流量,允许术者安全地完成潜在危险性的操作.     

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.     

多系统萎缩的脑干听觉诱发电位

本组对19例多系统萎缩(MSA)患者,21例帕金森氏病(PD)患者,及19例正常对照组个体作了BAEP检查。结果表明在MSA患者组中,84.2％BAEP异常,而在PD组中则几乎均为正常。这种差异在临床的鉴别诊断中是重要的。结合适当的临床特征,异常的BAEP及CT或MR所见,可及早对MSA作出正确诊断。     

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.     

Middle latency auditory evoked potentials (MLAEPs) in (MS)

Middle latency auditory evoked potentials (MLAEPs) were studied in 30 definite multiple sclerosis (MS) patients in addition to brain-stem auditory evoked potentials (BAEPs). BAEP abnormalities were detected in 18 (60%) patients. MLAEPs were abnormal in 22 (73%) of them. In 15 patients BAEPs and MLAEPs were both abnormal. MLAEPs were found abnormal in 7 of the 12 patients with normal BAEPs. In 18 patients with abnormal BAEPs only 3 had normal MLAEPs. MLAEPs abnormalities are consistent with a rostral auditory pathway involvement. Therefore, they can be used in combination with BAEPs to examine the whole auditory system to improve the sensitivity.     

BAEP changes in Leber's hereditary optic atrophy: further confirmation of multisystem involvement

A neurophysiological study of 11 patients belonging to 5 families affected by Leber's hereditary optic atrophy is reported. Electromyography, nerve conduction velocities and somatosensory evoked potentials were normal. Visual evoked potentials were absent or delayed, desynchronized and reduced in amplitude. Brainstem auditory evoked potentials were anomalous in 64% of subjects all without hearing defects. These changes which have never before been reported, confirm multisystem involvement in this disease.     

A remarkable patient – 40 years with probable multiple system atrophy (MSA)

A 58-year-old woman with a 40-year history of very slowly progressive Multiple System Atrophy is described. Received: 14 January 2003, Accepted: 7 March 2003 Correspondence to I. J. Schatz, M. D.     

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.     

Brainstem auditory evoked potentials in the diagnosis of multiple sclerosis

Brainstem auditory evoked potentials (BAEPs) have been investigated in 34 patients affected by Multiple Sclerosis. Abnormalities were found in 68% of the patients. Silent lesions of the brainstem were detected in 60% of the clinically definite and in 44% of the probable cases. The diagnostic value of these findings is discussed.

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Sommario I potenziali evocati uditivi sono stati investigati in 34 pazienti affetti da sclerosi multipla. Anormalità sono state evidenziate nel 68% dei pazienti affetti da sclerosi multipla clinicamente definita. Lesioni silenti del brainstem sono state trovate nel 60% delle forme clinicamente definite e nel 44% di quelle probabili. Il valore diagnostico di questi reperti è discusso.

     

Evoked potentials in hereditary spastic paraplegia

Pattern reversal visual evoked response (VER) and monaural stimulation of brainstem auditory evoked responses (BAER) were recorded from both sides in 25 patients (males 19; females 6) with hereditary spastic paraplegia (HSP). Their age ranged from 15–52 (mean±SD; 25.2±22.5) years and duration of symptoms 6 months-9 (mean±SD; 4.2±3.6) years. A prolonged P 100 latency was seen in 6 patients and BAER abnormality in 13. None of the patients had clinical evidence of brainstem involvement. It is suggested that VER and BAER abnormalities are due to segmental demyelination and fiber loss in central conduction pathways and could serve as an important tool for the diagnosis of this disorder.

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Sommario I potenziali evocati visivi (VER) e uditivi del tronco (BAER) sono stati registrati bilateralmente in 25 pazienti (19 maschi e 6 femmine) affetti da paraplegia spastica ereditaria (HSP). La loro età media era compresa tra 15 e 52 anni (media±DS=25.2±22.5) e con una durata di malattia compresa tra 6 mesi e 9 anni (media±DS=4.2±3.6). In 6 pazienti è stato riscontrato un aumento della latenza della P100 e in 13 i BAER erano anormali. Nessuno dei pazienti presentava segni clinici di coinvolgimento del tronco. Viene ipotizzato che le anormalità osservate ai VER e BAER sono dovute ad una demielinizzazione segmentaria o a perdita di fibre lungo le vie di conduzione cerebrale. Questi esami strumentali sarebbero quindi di grande utilità nella diagnosi di HSP.

     

帕金森病早期多种诱发电位检测的临床诊断价值

目的 观察帕金森病早期体感诱发电位(SL-SEP)、脑干听觉诱发电位(BAEP)和视觉诱发电位(PR-VEP)的异常特征．寻找敏感可靠的诊断指标。方法 对一组52例Yahr分期为Ⅰ期的帕金森病人和一组40例年龄匹配的健康对照组进行三种诱发电位观测。结果帕金森病早期SLSEP异常率为69．2％；BAEP的异常率为32．7％：PR-VEP的异常率为30、7％，病例组SL-SEP各主波峰潜伏期、峰间潜伏期、P25和N30波幅与对照组比较差异有湿著性意义；病例组BAEPⅠ—ⅢIPL、Ⅲ—ⅤIPL、Ⅰ一Ⅲ／Ⅲ一Ⅴ比值和PR-VEP的P100PL与对照组比较差异无显著性意义．结论 在帕金森病的早期，皮层感觉处理过程已受到干扰：体感诱发电位中央前成份以及顶成份P25是一个敏感的诊断指标。     

Brainstem auditory evoked potentials in tuberous sclerosis

Brainstem auditory evoked potentials were recorded in 4 subjects and pattern reversal evoked potentials in 1 subject, all with tuberous sclerosis. Alterations were found (absence or delay of components and prolonged interpeak intervals) which may suggest impaired nervous conduction also at brainstem level in patients with tuberous sclerosis.

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Sommario Sono stati registrati i potenziali evocati auditivi troncoencefalici in 4 soggetti con sclerosi tuberosa, in uno di essi sono stati registrati anche i potenziali evocati visivi da pattern reversal. Sono state ritrovate alterazioni delle risposte (assenza o ritardo di alcune componenti ed intervalli interpicco prolungati) che possono suggerire l'esistenza di una conduzione nervosa alterata anche a livello del tronco dell'encefalo nei pazienti con sclerosi tuberosa.

     

Present criteria for the diagnosis in vivo of olivopontocerebellar atrophy

We present 6 cases of olivopontocerebellar atrophy (OPCA) of Dèjérine-Thomas type. The diagnosis was based on an appropriate clinical picture, anomalous brainstem auditory evoked potentials (BAEP) and computerized tomography (CT) and/or magnetic nuclear resonance (MNR) imaging which demonstrated atrophy of the cerebellum and the pons. We believe that these methods will provide greater uniformity in the diagnosis of such an heterogeneous entity as OPCA.     

Involvement of the auditory brainstem system in spinocerebellar ataxia type 2 (SCA2), type 3 (SCA3) and type 7 (SCA7)

Aims: The spinocerebellar ataxia type 2 (SCA2), type 3 (SCA3) and type 7 (SCA7) are clinically characterized by progressive and severe ataxic symptoms, dysarthria, dysphagia, oculomotor impairments, pyramidal and extrapyramidal manifestations and sensory deficits. Although recent clinical studies reported additional disease signs suggesting involvement of the brainstem auditory system, this has never been studied in detail in SCA2, SCA3 or SCA7. Methods: We performed a detailed pathoanatomical investigation of unconventionally thick tissue sections through the auditory brainstem nuclei (that is, nucleus of the inferior colliculus, nuclei of the lateral lemniscus, superior olive, cochlear nuclei) and auditory brainstem fibre tracts (that is, lateral lemniscus, trapezoid body, dorsal acoustic stria, cochlear portion of the vestibulocochlear nerve) of clinically diagnosed and genetically confirmed SCA2, SCA3 and SCA7 patients. Results: Examination of unconventionally thick serial brainstem sections stained for lipofuscin pigment and Nissl material revealed a consistent and widespread involvement of the auditory brainstem nuclei in the SCA2, SCA3 and SCA7 patients studied. Serial brainstem tissue sections stained for myelin showed loss of myelinated fibres in two of the auditory brainstem fibre tracts (that is, lateral lemniscus, trapezoid body) in a subset of patients. Conclusions: The involvement of the auditory brainstem system offers plausible explanations for the auditory impairments detected in some of our and other SCA2, SCA3 and SCA7 patients upon bedside examination or neurophysiological investigation. However, further clinical studies are required to resolve the striking discrepancy between the consistent involvement of the brainstem auditory system observed in this study and the comparatively low frequency of reported auditory impairments in SCA2, SCA3 and SCA7 patients.     

ELECTROPHYSIOLOGICAL EVALUATION OF GENITO-SPHINCTERIC DYSFUNCTION IN MULTIPLE SYSTEM ATROPHY

Thirteen patients with multiple system atrophy underwent multimodality neurophysiological evaluation, including sphincteric needle electromyography (EMG), sacral reflexes, pudendal nerve terminal latency, pudendal (PSEPs) and tibialis posterior nerve somatosensory evoked potentials (TPSEPs), and perineal motor evoked potentials (PMEPs). EMG revealed denervation or neurogenic changes, with reduction in spontaneous tonic activity at rest and abnormal pudendal nerve terminal latency in 10 patients (76.9%); anal reflex was delayed in 7 patients (53.8%). TPSEPs scalp responses were clearly abnormal in 4 patients (30.7%), whereas PSEPs exhibited changes in 9 (69.2%): in 6 patients responses were delayed at lumbar level (46.2%), and in 5 over the scalp (38.4%). PMEPs showed an increase in latency with a mild prolongation of central motor conduction time (CMCT) in 2 cases (15.3%); 1 patient had prolonged latencies following both cortical and sacral stimulation, but a normal CMCT. Even if diagnostic yield is not improved using these investigations they provide evidence of multiple lesion sites other than Onuf's nucleus.­­     

Brainstem Auditory and Somatosensory Evoked Potentials in Neuro-Behqet's Syndrome

Abstract: Brainstem auditory evoked potentials (BAEPs) and somatosensory evoked potentials after median nerve stimulation (MN-SEPs) and after posterior tibial nerve stimulation (PTN-SEPs) were studied in 17 patients with neurolehget's syndrome (NB). Eleven patients (64.7%) showed an absence of wave I, III or V or a prolongation of the interpeak latency 1–111, or 111-V in BAEPs. Six patients (37.4%) showed a prolongation in the latency of cortical P37 of PTN-SEPs and/, or the interpeak latency EP-N13 or N13–N18 of MN-SEPs. The BAEP and SEP abnormalities indicated a conduction failure of the acoustic lateral lemniscus pathway and the medial lemniscus pathway in the brainstem of the patients with NB. Abnormal EPs can provide sensitive information which shows the presence of subclinical lesions in the central nervous system.