Magnetic resonance imaging in multiple sclerosis: investigation of brain and spinal cord lesions

Magnetic resonance imaging (MRI) of the brain was performed on forty-five patients with multiple sclerosis (MS), using T1-weighted inversion recovery and T2-weighted spin echo images, and the results were compared with X-ray computed tomography (CT). Some of the 45 MS patients were also examined by neurophysiological studies (visual evoked potentials and auditory brainstem responses) to compare with the brain MRI findings. MRI showed demyelinating plaques of the brain in 20 (74%) of 27 patients with brain symptoms, 11 (61%) of 18 patients without symptoms and 31 (69%) of all 45 patients. In 27 patients with brain symptoms, MRI was able to detect brain lesions in 6 (86%) of 7 acute stage patients and 14 (70%) of 20 non-acute stage patients. Furthermore, MRI was able to detect brain lesions in 21 (70%) of 30 clinically definite MS patients and 10 (67%) of 15 clinically probable MS patients. X-ray CT was performed on all 45 patients and was able to detect brain lesions in 9 (33%) of 27 patients with brain symptoms and 1 (6%) of 18 patients without symptoms. Visual evoked potentials were evaluated in 31 patients, and showed abnormalities in 1 (11%) of 9 patients without symptoms of optic neuritis and 100% of 22 patients with symptoms. Auditory brainstem responses were evaluated in 19 patients, and showed abnormalities in 1 (11%) of 9 patients without brainstem symptoms and 3 (30%) of 10 patients with symptoms. MRI of the brain was markedly superior to X-ray CT, visual evoked potentials and auditory brainstem responses in detecting clinically unsuspected lesions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Kainic acid differentiates GABA receptors from benzodiazepine receptors in the rat cerebellum

In a combined psychophysical-electrophysiological study on 29 patients with multiple sclerosis (MS), a compromised ability to make interaural time discriminations was nearly always found to be associated with ‘abnormal’ brain stem potentials evoked by clicks to at least one ear. However, no obvious relationships were found between evoked brain stem potentials and several other auditory behavioral measures such as interaural intensity discrimination, pure-tone thresholds and speech discrimination.     

Brain stem auditory evoked potentials are related to interaural time discrimination in patients with multiple sclerosis

In a combined psychophysical-electrophysiological study on 29 patients with multiple sclerosis (MS), a compromised ability to make interaural time discriminations was nearly always found to be associated with ‘abnormal’ brain stem potentials evoked by clicks to at least one ear. However, no obvious relationships were found between evoked brain stem potentials and several other auditory behavioral measures such as interaural intensity discrimination, pure-tone thresholds and speech discrimination.     

瞬目反射及脑干听觉诱发电位对脑干梗死疗效的评价

目的探讨瞬目反射和脑干听觉诱发电位对脑干梗死患者疗效的评价作用。方法40例经临床症状、体征定位于脑干髓内并经头部MRI检查明确诊断的脑干梗死患者(脑桥梗死31例、中脑梗死4例和延髓梗死5例),分别计算治疗前后瞬目反射各成分的平均潜伏期;观察脑干听觉诱发电位波形及各波潜伏期、峰间期的变化。结果经治疗后40例患者临床症状及体征均有不同程度改善,治疗前后瞬目反射各成分平均潜伏期之间差异无统计学意义(P>0.05);3例脑桥梗死患者R1波恢复正常,临床基本痊愈。治疗前后脑干听觉诱发电位各波潜伏期及峰间期比较,差异亦无统计学意义(P>0.05);治疗后中脑梗死及脑桥梗死患者各有2例恢复正常,临床症状明显好转。结论瞬目反射与脑干听觉诱发电位均能敏感地反映脑干功能的变化,与临床表现具有一致性,但在发病15d内大部分病例的电生理活动不能恢复正常。     

The diagnostic reliability of magnetically evoked motor potentials in multiple sclerosis.

In a prospective study, we evaluated the technique of magnetically evoked motor potentials (MEP) in the diagnosis of multiple sclerosis (MS). We consecutively included 68 patients with symptoms or signs compatible with a demyelinative CNS affection. We subjected all patients to CSF analysis, MRI studies of the brain and brainstem, visual evoked potentials (VEP), brainstem auditory evoked potentials (BAEP), and somatosensory evoked potentials (SSEP). We then used the results to categorize the patients according to the Poser criteria of multiple sclerosis. Blinded from the results of the above investigations, one of the authors made MEP recordings from three muscles in the upper limbs and two in the lower limbs in all 68 patients. Forty patients received an MS diagnosis, and in these, MRI was positive in 88%, MEP in 83%, VEP in 67%, SSEP in 63%, and BAEP in 42%. As to the diagnosis of MS, the reliability of a prolonged central motor conduction time (CMCT) was 0.83 (0.73 to 0.93), while the reliability of a normal CMCT was 0.75 (0.61 to 0.98). The information gained by MRI was best supplemented by VEP. Of the neurophysiologic tests, the MEP was in closest agreement with the MRI with a concordance of 85%.     

Magnetic resonance imaging in clinically isolated lesions of the brain stem.

Twenty-seven patients with an isolated brain stem syndrome, thought to be due to demyelination, were examined by magnetic resonance imaging (MRI). A brain stem lesion was identified in 25, and clinically silent lesions outside the brain stem were demonstrated in 20. MRI was more sensitive than evoked potentials in detecting brain stem and other lesions. The scan findings were compared with those in 23 patients with multiple sclerosis, who had chronic brain stem dysfunction, with particular reference to the distribution of abnormalities and the MRI characteristics of the lesions. The relaxation times, T1 and T2, of the lesions were measured by MRI. These values were seen to fall in serial studies of acute lesions, but remained unchanged in the chronic lesions. MRI may therefore allow the age of lesions to be assessed.     

Magnetic resonance imaging in patients with multiple sclerosis and spinal cord involvement: 28 cases

In patients with clinically isolated spinal disease, magnetic resonance imaging (MRI) provides a non-invasive method of detecting surgically treatable causes and is also useful in detecting asymptomatic brain lesions where the cord syndrome is due to multiple sclerosis (MS). We report the findings of spinal and brain MRI in 28 patients with spinal cord disorder due to MS. It was possible to detect intrinsic plaques reliably in the majority of patients (60.7%) with clinical findings of spinal cord MS. The results of MRI are compared with the clinical status and with cerebrospinal fluid findings and evoked potentials.     

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.     

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。     

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。     

Central motor conduction as a measure of disease progression in early multiple sclerosis

We monitored disease progression in 27 patients with clinically or laboratory-supported definite multiple sclerosis by means of clinical assessments [expanded disability status scale (EDSS), and the neurologic rating scale (NRS)] repeated at 6 month intervals for 2 years. Each clinical assessment was accompanied by evoked potentials (EP; visual, brain stem auditory, and somatosensory evoked potentials), motor evoked potentials elicited by magnetic stimulation, and magnetic resonance imaging of the brain and brain stem. Central conduction indices were calculated for each central pathway. According to the EDSS 18 patients deteriorated, eight were unchanged and one improved. The central motor conduction index (CMCI) was the only conduction parameter which correlated significantly with both EDSS and NRS at baseline [rho=0.51 (EDSS); -0.65 (NRS)], at final investigation, and when individual changes from baseline to final investigation were addressed (rho=0.38; -0.38). Individual deteriorations or improvements of the CMCI during the 2 years correlated with changes in both EDSS and NRS (rho = 0.51; -0.38). The MRI parameters did not correlate with the clinical scores. The concordance between MRI and CMCI in detection of disease activity was 63%. We conclude that the CMCI stands out as an objective, accurate and easily obtained outcome parameter.     

Multiple sclerosis diagnosis: magnetic resonance imaging compared with other paraclinical examinations

Examination by magnetic resonance imaging (MRI), evoked potentials (EP) and cerebrospinal fluid (CSF) analyses was carried out on 97 definite, 20 probable and 40 possible multiple sclerosis (MS) patients (McAlpine's clinical criteria). MRI of only 4 transverse brain sections at the level of the ventricles and the analysis of the first 4 echoes showed periventricular or parenchymal lesions, or both, in 114 of the 117 definite and probable MS patients and in 25 of the possible MS patients. MRI was more sensitive than the CSF analyses or EP. The MRI abnormalities were not, however, MS-specific.     

A new method to investigate brain stem structural–functional correlations using digital post-processing MRI – reliability in ischemic internuclear ophthalmoplegia

We investigated the reliability of a new digital post-processing magnetic resonance imaging (MRI) technique in ischemic brain stem lesions to identify relations of the lesion to anatomical brain stem structures. The target was a medial longitudinal fasciculus (MLF) lesion, which was evident from ipsilateral internuclear ophthalmoplegia (INO). Sixteen patients with acute unilateral INO and an isolated acute brain stem lesion in T2- and EPI-diffusion weighted MRI within 2 days after the onset of symptoms were studied. The MRI slice direction was parallel and perpendicular to a slice selection of a stereotactic anatomical atlas. The individual slices were normalized and projected in the digitalized atlas. The eye movement disorder was monitored by electro-oculography. In all patients with clinical or subclinical electro-oculographically documented INO and MRI proven brain stem infarction the lesion covered or at least partially overlapped the ipsilateral MLF at one or more atlas levels. We conclude that digital post-processing MRI with normalizing and projecting brain stem lesions in an anatomical atlas is a reliable method to demonstrate the anatomical structures involved by the lesion. Combined with electrophysiological brain stem testing, this method may be a useful tool to identify incompletely understood pathways mediating brain stem reflexes or the generators of evoked potentials.     

Myelopathy patients studied with magnetic resonance for multiple sclerosis plaques

Seven patients with isolated spinal cord symptoms, and with evoked potential (EP) recordings and/or cerebrospinal fluid (CSF) findings supporting a demyelinating cause for their myelopathy, were examined with cervical and cranial magnetic resonance imaging (MRI). Lesions in the cervical spinal cord were detected in 6 of the patients, including 2 who also had disseminated lesions in the brain compatible with multiple sclerosis (MS). In one patient MRI of the cervical spinal cord was normal, while plaques were seen in the periventricular region of the brain and in the brain stem. Thus, in the 3 patients with cerebral plaques, MRI supported the diagnosis of MS by showing dissemination in space. In the remaining 4 patients MRI provided support for the diagnosis of MS by demonstrating the cervical spinal cord plaques while excluding other potential causes of myelopathy, such as spinal cord compression and intramedullary tumor.     

Familial multiple sclerosis: case study of three affected siblings

We report on three sisters with new-onset multiple sclerosis (MS). The symptoms of the eldest sister began in 1993 with lower-limb weakness and paraesthesia. In 1998, she had limb weakness, nystagmus and ataxia. Magnetic resonance imaging (MRI) of the brain, the cerebrospinal fluid (CSF) examinations, and evoked potentials verified MS. The middle sister exhibited left-side optic neuritis in 1998. All findings pointed to MS. The third sister had subjective complaints such as paraesthesias and vertigo. MRI and CSF results supported the diagnosis. Both parents and all four grandparents are without neurological signs; the brain MRI examinations on the parents were negative. The prevalence of familial MS in first-degree relatives is 5-10%, while that in twins is 20-30%. In this case, environmental factors seem to play the crucial role. Although the anamnesis as concerns MS proved negative in the other family members examined here, further genetic examination of the sisters is needed.     

Recomendaciones para la utilización clínica del estudio de potenciales evocados motores en la esclerosis múltiple

Objective

To establish clinical guidelines for the clinical use and interpretation of motor evoked potentials (MEP) in diagnosing and monitoring patients with multiple sclerosis (MS). Recommendations for MEP use and interpretation will help us rationalise and optimise resources used in MS patient diagnosis and follow up.

Method

We completed an extensive literature review and pooled our own data to produce a consensus statement with recommendations for the clinical use of MEPs in the study of MS.

Results

MEPs, in addition to spinal and cranial magnetic resonance imaging (MRI), help us diagnose and assess MS patients whose disease initially presents as spinal cord syndrome and those with non-specific brain MRI findings, or a normal brain MRI and clinical signs of MS.

Conclusions

Whenever possible, a multimodal evoked potential study should be performed on patients with suspected MS in order to demonstrate involvement of the motor pathway which supports a diagnosis of dissemination in space.     

Clinical, magnetic resonance imaging, cerebrospinal fluid and electrophysiological characteristics of the earliest multiple sclerosis

OBJECTIVES: The vast majority of clinically isolated syndrome (CIS) patients with at least two silent brain MRI lesions progress to multiple sclerosis (MS) as early as after 2 years meaning that they actually have MS, the earliest MS. Effective therapy with interferon beta preparations in patients with the earliest MS demands early and accurate diagnosis of the disease. PATIENTS AND METHODS: In order to find the differentiating clinical and paraclinical characteristics of patients with the earliest MS we compared clinical, MRI, CSF and evoked potential findings in patients with the earliest MS and patients with relapsing-remitting (RR) MS. Retrospective analysis included 149 patients (103 women), among them 40 patients with the earliest MS and 95 patients with RR MS. RESULTS: Patients with the earliest MS had more often predominant afferent symptoms (p=0.023) but less often predominant cerebellar (p=0.033) and efferent symptoms (p=0.012) than patients with RR MS. They were less likely to fulfill the Barkhof brain MRI criteria (p=0.050) and had less often prolonged latencies of visual evoked potentials (VEP) (p=0.006) than patients with RR MS. On the other hand they were more likely to have elevated CSF cells (p=0.010) than patients with RR MS and had as often present CSF oligoclonal bands (p=0.112). CONCLUSION: The differentiating characteristics of patients with the earliest MS are predominance of afferent symptoms, less brain MRI dissemination and more frequently normal VEP, but on the other hand abnormal CSF findings with elevated CSF cells and positive oligoclonal bands.     

Electrophysiological brain stem investigations in idiopathic narcolepsy

Narcolepsy is associated with various rapid eye movement (REM) sleep abnormalities. Distinct brain stem areas seem to play a prominent role in REM sleep regulation. Recent magnetic resonance imaging (MRI) studies have led to conflicting findings concerning the presence of structural brain stem lesions in patients with idiopathic narcoleptic syndrome. However, multimodal electrophysiological brain stem investigations may reveal functional brain stem abnormalities even in the absence of MRI abnormality. Therefore we investigated brain stem function in 12 idiopathic narcoleptic patients by systematically studying tegmental brain stem pathways. All of the patients met the diagnostic criteria of the International Classification of Sleep Disorders, with typical changes in polysomnography and the multiple sleep latency test. Electrophysiological investigations comprised masseter reflex, blink reflex, masseter inhibitory reflex, early auditory evoked potentials and electrooculography with vestibular testing. In no patient were electrophysiological brain stem abnormalities observed. Our findings do not support the existence of a relevant brain stem lesion in narcoleptic patients with normal neurological status. Received: 23 September 1997 Received in revised form: 23 January 1998 Accepted: 10 February 1998     

Brain stem auditory evoked potentials and blink reflexes in quiescent multiple sclerosis.

Brain stem auditory evoked potentials (BAEP) and blink reflexes (BR) were studied in 25 patients with multiple sclerosis (MS), the diagnosis being definite according to McAlpine's criteria, in the quiescent phase, without signs of brain stem involvement. BAEP abnormalities were found in 64% of the cases and BR abnormalities in 60%. A good correlation between the two tests was found in most patients. The abnormalities consisted of delayed latencies and/or high intraindividual variability in shape and latency of BAEP and BR components. It seems that demyelination of brain stem pathways results not only in conduction slowing but also in more serious dysfunction of the generators of the evoked components.     

Failure to develop multiple sclerosis in patients with neurologic symptoms without objective evidence

BACKGROUND: Many patients referred to multiple sclerosis (MS) centers with symptoms suggestive of MS are found to have normal neurologic examinations, normal or non-specific brain magnetic resonance imaging (MRI) scan findings, and normal cerebrospinal fluid (CSF). Persistent symptoms often lead to multiple consultations and repeated diagnostic investigations. We performed a study to evaluate the diagnostic utility of repeated evaluations in patients with normal initial assessments and persistent neurologic symptoms. METHODS: 143 patients were evaluated initially and 109 returned for a second evaluation after a mean interval of 4.4 years. RESULTS: All 143 patients had normal initial examinations, brain MRI scans, screening blood tests, and CSF studies. Spinal cord imaging was normal in all patients tested (cervical cord, n = 126; 88.1%; thoracic cord, n = 58; 40.6%). Evoked potential studies were abnormal in a small percentage of patients: visual evoked potentials, VEP (8.1%), somatosensory evoked potentials, SSEP (4.9%), and brainstem auditory evoked potentials, BAEP (2.8%). All follow-up patients (n = 109) had normal examinations and MRI scans. Repeat CSF studies (n = 35; 32.1%) and spinal cord imaging (cervical cord n = 57; 52.3%; thoracic cord n = 32; 29.4%) were normal in all follow-up patients tested. No patients at initial presentation or at follow-up fulfilled diagnostic criteria for MS. CONCLUSIONS: PATIENTS: and clinicians may be reassured that persistent neurologic symptoms in the absence of objective clinical evidence do not lead to the development of MS. Costly serial investigations should be carefully considered, particularly in the presence of normal neurologic examination at follow-up.