Seizures in multiple sclerosis

Seizures in inflammatory demyelinating disorders of the central nervous system

BACKGROUND

Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may be associated with acute symptomatic seizures and chronic epilepsy as well. The clinical features of the seizures and/or accompanying epilepsy seen in each disease group may vary. In this study, we aimed to contribute to the existing literature by describing the clinical features of seizures and epilepsy in our demyelinating patient population.

METHODS

We retrospectively analyzed patients who were followed up in our tertiary referral center neurology demyelinating diseases outpatient clinic between 2019 and 2024. Patients who had at least one seizure before, simultaneously, or after the diagnosis of demyelinating disease were included in the study.

RESULTS

Among 1735 patients with MS, 40 had experienced at least one epileptic seizure (2.3 %). Thirty patients (1.7 %) had seizures that could not be explained by another factor than MS. When secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS) were compared, the interval between MS-epilepsy diagnosis was longer and seizure recurrence was more in SPMS. However, the prognosis of epilepsy was good in both subtypes. There were 21 patients followed up with antibody-positive neuromyelitis optica spectrum disorder. No patient had a seizure during the follow-up. We identified 56 patients who fulfilled the criteria for MOGAD with high antibody titers. Seizures were observed in three of them (5.4 %). All of them had status epilepticus either at the onset or during the course of the disease.

CONCLUSION

Even rare, seizures constitute one of the important clinical features of the inflammatory demyelinating disorders of the central nervous system. The pathophysiologic mechanism underlying seizures in MS is still not clear. Seizures may occur through different mechanisms in patients where seizures are the initial symptom or a sign of relapse and those that occur spontaneously during the progressive course of the disease. Prevalence of status epilepticus was common in MOGAD patients. Given the rarity of the seizures in CNS demyelinating disorders, it is difficult the define clinical and pathophysiological characteristics of accompanying seizures and epilepsy. Future studies conducted on large patient groups will contribute to the existing literature.

Epilepsy and demyelination: Towards a bidirectional relationship

Demyelination stands out as a prominent feature in individuals with specific types of epilepsy. Concurrently, individuals with demyelinating diseases, such as multiple sclerosis (MS) are at a greater risk of developing epilepsy compared to non-MS individuals. These bidirectional connections raise the question of whether both pathological conditions share common pathogenic mechanisms. This review focuses on the reciprocal relationship between epilepsy and demyelination diseases. We commence with an overview of the neurological basis of epilepsy and demyelination diseases, followed by an exploration of how our comprehension of these two disorders has evolved in tandem. Additionally, we discuss the potential pathogenic mechanisms contributing to the interactive relationship between these two diseases. A more nuanced understanding of the interplay between epilepsy and demyelination diseases has the potential to unveiling the molecular intricacies of their pathological relationships, paving the way for innovative directions in future clinical management and treatment strategies for these diseases.

Incidence and determinants of seizures in multiple sclerosis: a meta-analysis of randomised clinical trials

BACKGROUND

Seizures are reported to be more prevalent in individuals with multiple sclerosis (MS) compared with the general population. Existing data predominantly originate from population-based studies, which introduce variability in methodologies and are vulnerable to selection and reporting biases.

METHODS

This meta-analysis aims to assess the incidence of seizures in patients participating in randomised clinical trials and to identify potential contributing factors. Data were extracted from 60 articles published from 1993 to 2022. The pooled effect size, representing the incidence rate of seizure events, was estimated using a random-effect model. Metaregression was employed to explore factors influencing the pooled effect size.

RESULTS

The meta-analysis included data from 53 535 patients and 120 seizure events in a median follow-up of 2 years. The pooled incidence rate of seizures was 68.0 per 100 000 patient-years, significantly higher than the general population rate of 34.6. Generalised tonic-clonic seizures were the most common type reported, although there was a high risk of misclassification for focal seizures with secondary generalisation. Disease progression, longer disease duration, higher disability levels and lower brain volume were associated with a higher incidence of seizures. Particularly, sphingosine-1-phosphate receptor (S1PR) modulators exhibited a 2.45-fold increased risk of seizures compared with placebo or comparators, with a risk difference of 20.5 events per 100 000 patient-years.

CONCLUSIONS

Patients with MS face a nearly twofold higher seizure risk compared with the general population. This risk appears to be associated not only with disease burden but also with S1PR modulators. Our findings underscore epilepsy as a significant comorbidity in MS and emphasise the necessity for further research into its triggers, preventive measures and treatment strategies.

Multiple sclerosis and seizures: A retrospective observational study in a multiple sclerosis autoimmunity center of excellence

PURPOSE

The prevalence of epilepsy in patients with multiple sclerosis (MS) is three to six times the prevalence in the general population. Mechanisms resulting in increased seizure risk are not fully understood. Our objective is to characterize patients with MS and epilepsy regarding timing of diagnoses, MS and seizure (SZ) type, EEG findings suggesting cortical dysfunction, frequency of status epilepticus (SE), and seizure freedom.

METHODS

This was a single center retrospective study. Cases were obtained via DataDirect via the University of Michigan electronic medical record from January 1, 2006 through October, 12, 2016. The University of Michigan Health System is a large academic institute with a tertiary referral center and an Autoimmunity Center of Excellence. Patients were included if chart listed one or more of the top 62 epilepsy, and one or more of the top 2 MS, most frequently entered ICD9 and ICD10 codes. Patients with alternative epilepsy etiology were excluded. 74 of 361 patients were included. We collected information regarding demographics, MS and SZ type, age at diagnosis, imaging, EEG, seizure freedom, medications, and SE.

RESULTS

We found a high percentage of patients with SE. Most patients with imaging had multiple lesions at seizure onset. 27/54 of patients with EEG data showed electrographic evidence of cortical dysfunction. 6/8 of EEGs in PPMS showed features consistent with cortical dysfunction, followed by 9/17 in SPMS and 11/23 in RRMS. 7/8 of patients with PPMS showed EEG evidence of temporal lobe dysfunction.

CONCLUSION

Time of seizure onset relative to MS diagnosis varied with MS type suggesting distinct pathophysiology. EEG results correspond with reports of increased cortical damage and temporal dysfunction in PPMS, but are unique as a functional modality (EEG) as indicator of gray matter dysfunction. EEG findings differed in RRMS and progressive MS suggesting possibility of supportive diagnostic marker. Our data suggests higher risk of SE in progressive MS and diminished rate of seizure freedom for MS patients with SE. We conclude that early treatment with antiseizure medication would be beneficial for MS patients with SE and with progressive MS forms and SZ, in agreement with previous studies.

The impact of the comorbid seizure/epilepsy on the health related quality of life in people with multiple sclerosis: an international multicentric study

Introduction

The health-related quality of life (HRQoL) of people with (Pw) multiple sclerosis (MS) is usually deteriorated. It has been recently suggested that comorbidities may have the negative influence on the quality of life of the PwMS, but according to the best of our knowledge, only one study investigated, although in a very small cohort, the impact of individual comorbidity on the quality of life of PwMS. The aim of our investigation was to assess, in an international, multicentric study, the impact of comorbid seizure/epilepsy on the HRQoL in PwMS.

Methods

We conducted cross-sectional study at numerous neurological centers in Serbia, Croatia, Bulgaria, Montenegro, Northern Macedonia, and Bosnia and Herzegovina (Federation of Bosnia and Herzegovina and Republic of Srpska). For each patient, demographic and clinical data were collected, including Expanded disability status scale (EDSS) score. Beck Depression Inventory (BDI) and the 36-Item Short Form Health Survey (SF-36) questionnaires were administered to all patients.

Results

The study comprised 326 PwMS in total, 127 PwMS with seizure/epilepsy and 209 PwMS without. Both mean Physical health composite (PHC) and mental health composite (MHC) scores, were statistically significantly higher in PwMS without seizure/epilepsy, implicating worse quality of life in PwMS with comorbid seizure/epilepsy. Presence of seizure/epilepsy in pwMS was statistically significant independent predictor of both PHC and MHC, in multivariate linear regression model after adjustment for potential confounding variables. The hierarchical multivariate regression analysis was performed in order to establish the most important predictors of the PHC and MHC of the SF-36, in PwMS with seizure/epilepsy; older age, higher level of disability, as measured by EDSS, higher depression score, drug-resistant epilepsy and shorter time since last seizure were found to significantly predict worse MHC score in PwMS with seizure/epilepsy.

Discussion

Our results point to the possible role of theinterventions related to the adequate control of epilepsy along with improvement of the mental health status to be important in order to reduce MS burden in the PwMS with comorbid seizure/epilepsy.

Association between multiple sclerosis and epilepsy: A systematic review and meta-analysis

BACKGROUND

Seizures in people with multiple sclerosis (MS) are reported; however, the risk of epilepsy in adults with MS remains poorly defined.

METHODS

We performed a systematic review and meta-analysis to evaluate the incidence and prevalence of epilepsy in adults (≥ 18 years) with MS compared to those without. We searched MEDLINE and EMBASE from inception to July 1, 2022 to include observational studies that reported the prevalence or incidence of epilepsy in adults with MS and a comparator group, consisting of adults without MS or the general population. We used the Newcastle Ottawa Scale to evaluate quality of the included studies. We performed random-effects meta-analyses to determine the prevalence and incidence of epilepsy in adults with MS compared to the non-MS group.

RESULTS

We identified 17 studies consisting of 192,850 adults with MS, across nine countries. Most studies were of moderate quality as they did not specify the MS type or type of seizures. Compared to a comparison group, both the prevalence (pooled OR 2.04; 95% confidence interval 1.59-2.63, I² = 95.4, n = 12) and the incidence of epilepsy (pooled RR 3.34; 3.17-3.52, I² = 4.6%, n = 6) was higher in people with MS. Heterogeneity in estimates was not explained by additional analyses.

CONCLUSIONS

MS is an independent risk factor for both incident and prevalent epilepsy, suggesting variation in grey matter involvement over the disease course. Longitudinal studies are required to help identify patient and disease characteristics associated with epilepsy.

Multiple Sclerosis and Autoimmune Comorbidities

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system characterized by broad inter- and intraindividual heterogeneity and different prognoses. Multisystem comorbidities are frequent features in people with MS (PwMS) and can affect treatment choices, quality of life, disability and mortality. In this scenario, autoimmune comorbidities play a cardinal role for several reasons, such as the implication on MS pathogenesis, diagnostic delay, disease activity, disability progression, brain atrophy, and treatment choice. However, the impact of an autoimmune comorbid condition on MS is not fully elucidated. This review aims to summarize the currently available data on the incidence and prevalence of autoimmune diseases in PwMS, the possible effect of this association on clinical and neuroradiological MS course and its impact on treatment choice.

Seizures and epilepsy in multiple sclerosis, aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

Seizure is one of the manifestations of central nervous system (CNS) inflammatory demyelinating diseases, which mainly include multiple sclerosis (MS), aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). "Acute symptomatic seizures secondary to MS / AQP4-NMOSD / MOGAD" occur in the acute phase of the diseases, and are more frequent in MOGAD. In contrast, recurrent non-provoked seizures, mainly attributed to "autoimmune-associated epilepsy", occur in the non-acute phase of the diseases. Seizures in MS / AQP4-NMOSD / MOGAD mostly have a focal-onset. MS patients with concomitant systemic infections, an earlier onset and a higher disease activity are more likely to have seizures, whereas factors such as higher MS severity, the presence of status epilepticus and cortical damage indicate a greater risk of developing epilepsy. In MOGAD, cerebral cortical encephalitis, acute disseminated encephalomyelitis (ADEM)-like phenotypes (predominately ADEM and multiphasic disseminated encephalomyelitis) indicate a higher seizure risk. Multiple relapses with ADEM-like phenotypes predict epilepsy in pediatrics with MOGAD. Pathophysiologically, acute symptomatic seizures in MS are associated with neuronal hyperexcitability secondary to inflammation and demyelination. Chronic epilepsy in MS is largely due to gliosis, neuronal dysfunction and synaptic abnormalities. The mainstay of treatment for seizures secondary to MS / AQP4-NMOSD / MOGAD include immunotherapy along with antiseizure medications. This critical review discusses the most-updated evidence on epidemiology, clinical correlates, and inflammatory mechanisms underlying seizures and epilepsy in MS / AQP4-NMOSD / MOGAD. Treatment cautions including drug-drug interactions and the impact of treatments on the other are outlined. We also highlight pitfalls and challenges in managing such patients and future research perspectives to address unsolved questions.

Prevalence of Seizure/Epilepsy in Patients with Multiple Sclerosis: A Systematic Review and Meta-Analysis

Background

Seizure and epilepsy are among the initial symptoms of multiple sclerosis (MS), yet different prevalence rates are reported for them in the previous studies. The goal of this systematic review is to estimate the pooled prevalence of seizure and epilepsy in patients with MS.

Methods

We searched PubMed, Scopus, EMBASE, Web of Science, google scholar, and gray literature including references from identified studies and conference abstracts published up to October 2019. The search strategy included the MeSH terms and text words as ((Epilepsies OR Seizure Disorder OR Seizure Disorders OR Awakening Epilepsy OR Epilepsy, Awakening OR Epilepsy, Cryptogenic OR Cryptogenic Epilepsies OR Cryptogenic Epilepsy OR Epilepsies, Cryptogenic OR epilepsy OR seizure) AND (Multiple Sclerosis OR Sclerosis, Multiple) OR Sclerosis, Disseminated) OR Disseminated Sclerosis) OR MS (Multiple Sclerosis)) OR Multiple Sclerosis, Acute Fulminating).

Results

The literature review resulted in 4860 articles; 2593 articles remained after eliminating the duplicates. For the final analysis, 39 articles were included, 9 of which were conference abstracts. The pooled prevalence of seizure in MS cases was 2%, 95% confidence interval (CI)(1%-3%) (I² = 91.8%, P < 0.001). The pooled prevalence of epilepsy in MS cases was 3%, 95% CI (2%-4%) (I2 = 92.9%, P < 0.001). The pooled prevalence of epilepsy in Asia, Europe, and America was 6%, 3%, and 3%, respectively. The level of heterogeneity decreased after subgroup analysis in Asian and American subgroups. Meta-regression analysis showed continent is not a source of heterogeneity (coefficient = -0.007, P = 0.6).

Conclusions

The result of this systematic review shows that the pooled prevalence of seizure and epilepsy among MS patients is 2% and 3%, respectively.

EEG Biofeedback for Treatment of Psychogenic Non-Epileptic Seizures (PNES) in Multiple Sclerosis: A Case Report

The objective of the present study was to evaluate the effectiveness of EEG biofeedback for treatment of psychogenic non-epileptic seizures (PNES) in a patient with multiple sclerosis. The patient was a 47-year-old female who has been experiencing several PNES types after being diagnosed with multiple sclerosis. She underwent 16 sessions of the EEG biofeedback over a period of two months. Following EEG biofeedback, the patient reported that her PNES attacks had stopped and the treatment resulted in significant abatement in her clinical seizure symptoms. The analysis of sensorimotor rhythm (SMR) values revealed reduction of psychogenic non-epileptic seizure. The Beck Anxiety Inventory (BAI) and Word Health Organization Quality of Life Questionnaire (WHOQOL) were used before and after treatment. Decreased anxiety as well as increased quality of life was observed after treatment. Generally, the results indicated that EEG biofeedback was a useful procedure in treating PNES, promoting quality of life and reducing anxiety in our patient with multiple sclerosis.

Epileptic seizures in multiple sclerosis: prevalence, competing causes and diagnostic accuracy

Background

Multiple sclerosis (MS) is accompanied by an increased risk of epileptic seizures, but data with a detailed description of the competing causes are lacking.

Methods

We aimed to describe a cohort of patients with both MS and epileptic seizures in a retrospective, population-based study.

Results

We included 59 out of 2285 MS patients who had at least one epileptic seizure. Out of them, 22 had seizures before the diagnosis of MS, whereas epileptic seizures occurred after MS diagnosis in 37 patients, resulting in a total prevalence of epileptic seizures in MS of 2.6%. Competing causes could be found in 50.8% (30/59) of all patients, with 40.9% (9/22) compared to 56.8% (21/37) of the MS patients with seizures before vs after MS diagnosis. The main alternative causes were traumatic brain injury and cerebral ischemia accounting for more than 30% of the patients, with no difference between the subgroups. 33.3% and 55.6% of MS patients with seizures before/after MS diagnosis had documented pathological EEG alterations.

Conclusion

A remarkable percentage of MS patients with epileptic seizures do have alternative competing causes at the time of the first seizure. A detailed diagnostic setup including patient history, EEG and MRI is recommended in the evaluation and choice for the best treatment.

Relevance of cerebrospinal fluid findings in patients with multiple sclerosis and seizures

Seizures occur 2-3 times more frequently in Multiple Sclerosis (MS) patients compared to the general population. The prevalence of seizures is reported to be 1.5-7.8% in MS population. However, it is unclear if seizure is an indirect symptom of neuroinflammation in MS. In our study, we explored the relevance of cerebrospinal fluid (CSF) findings in this unique patient cohort with MS and seizures. We retrospectively reviewed the charts of 32 MS patients with subsequent seizures (MSSS) and 12 patients with seizures followed by MS (SFMS). These two study groups were compared with two control groups - MS without seizures (MSNOS) and seizures without MS (SNOMS). Clinical characteristics and CSF findings between these groups were compared using boot strapped independent t-test. The CSF lymphocyte percentage of the SFMS group (95.6 ± 3) was significantly higher compared to MSNOS (66.0 ± 36.9, p = .04) and SNOMS (81.7 ± 10.0, p = .03). The CSF IgG index was significantly higher in SFMS group (1.9 ± 1.2, p = .02) as compared to MSSS group (0.99 ± 0.4). Patients with seizures as initial symptom of MS may have higher degree of CNS inflammation. Nonspecific clinical symptoms and atypical imaging findings in patients presenting with seizures may warrant close monitoring for development of MS.

Patients With Epileptic Seizures and Multiple Sclerosis in a Multiple Sclerosis Center in Southern Germany Between 2003-2015

Background: So far, many studies have shown that the risk of developing seizures and epilepsy is higher among patients with multiple sclerosis (MS) than in the general population. However, the causal link between these two diseases is still unclear. In addition, it is not clearly understood whether and to what extent the manifestation of seizures and epilepsy in patients with MS affects the clinical course and the long-term prognosis of the disease. We aimed to retrospectively identify and describe patients with MS and with seizures and epilepsy which were seen at the Department of Neurology of the University of Regensburg in Germany between the years 2003-2015. Methods: With the help of the electronic documentation system of hospital admitted patients followed by scrutinizing medical records of patients with MS for evidence of seizures and epilepsy, we identified patients with MS and seizures or epilepsy. Results: We identified 22 individuals (1.74%) out of 1,267 patients with MS with seizures or epilepsy. 18 of these 22 individuals met criteria for epilepsy (1.42%). Nine MS patients (40.9%) suffered from relapsing-remitting MS (RRMS) whereas 11 MS patients (50.0%) showed a secondary progressive disease course (SPMS). Five of those (45.5%) converted from RRMS to SPMS before they acquired epilepsy. None of the identified patients with MS and seizures or epilepsy suffered from primary progressive MS (PPMS). Moreover, two MS patients (9.1%) had a history of seizures before MS onset. Seizures were of focal onset in 17 patients with MS (77.3%). Fourteen out of these 17 MS patients presented with focal to bilateral tonic-clonic seizures (82.4%). Five MS patients (22.7%) showed tonic clonic seizures of unknown onset. Status epilepticus was reported in three patients with MS (13%), for one patient the data was inconclusive. Conclusion: The occurrence of seizures and epilepsy was higher than in the general population, suggesting a causal relationship between both diseases. In most cases, seizures occurred after the first manifestation of MS. The high frequency of focal seizures supports the concept of cerebral lesions in patients with MS playing an important role in precipitation of seizures and epilepsy.

Seizures and epilepsy in multiple sclerosis: epidemiology and prognosis in a large tertiary referral center

BACKGROUND

Seizures and epilepsy may substantially add to the burden of disease in multiple sclerosis (MS), whereas the exact prevalence and prognosis of seizures and epilepsy in patients with MS remains largely unknown.

OBJECTIVES

We aimed to investigate the epidemiology and prognosis of seizures and epilepsy in MS.

METHODS

We retrospectively analyzed a cohort of 4078 MS patients from a single tertiary referral clinic.

RESULTS

After excluding 37 patients with unconfirmed MS and alternative seizure etiologies, we found seizures attributable to MS in 1.5% and epilepsy in 0.9% of patients. 40.4% of patients with a follow-up of at least twelve months experienced only a single seizure and 59.6% had recurring seizures. 39% of patients with recurrent seizures were considered drug-resistant, with 9.7% experiencing status epilepticus. Seizure recurrence after a first seizure depended significantly on the MS subtype and was seen more often if the first seizure occurred simultaneously with a MS relapse than in the absence of a relapse.

CONCLUSION

Our study shows a lower number of seizures and epilepsy in MS than previously reported. While a single seizure in MS usually has a good prognosis, relapse-associated seizures and established epilepsy in MS may not be as benign as previously assumed.

Status Epilepticus and Multiple Sclerosis: A Case Presentation and Literature Review

PURPOSE

To search the literature for the frequency, pathogenesis, prognosis, and treatment of seizures and status epilepticus (SE) in patients with multiple sclerosis (MS).

METHODS

We report 2 patients with MS who presented with SE and review the literature.

RESULTS

Seizures and SE episodes worsened during MS relapses in the first patient. SE episodes and MS relapses significantly decreased after initiation of natalizumab treatment but she still had seizures and was taking 4 antiepileptic drugs (AEDs). The second patient had super refractory SE and was treated with AEDs and coma induction; SE was controlled in 1 week. Antibodies against glycine receptors were reported in her serum after her death.

CONCLUSION

SE has been reported to remain refractory to conventional AEDs, and improve with treatment of MS relapse. Seizures often occur during MS relapses, and might be the presenting symptom of MS or the only symptom of a relapse. Patients with MS and epilepsy have been reported to have more severe MS disease courses. Seizures are refractory to treatment in patients with MS with chronic epilepsy; however, prognosis is quite good in patients experiencing provoked seizures during an MS relapse. Since some EEG findings may have prognostic value, their evaluation is invaluable for the determination of outcome. No treatment guidelines have been specified for patients with MS and SE. However, treatment with AEDs, ideally new-generation AEDs, and an MS treatment review with a new protocol will ensure a fast response to the improvement of SE.

Treatment of epilepsy in multiple sclerosis

PURPOSE

The prevalence of epilepsy is increased in multiple sclerosis (MS), but information on AED treatment and seizure outcome is scarce. We describe epilepsy characteristics including the use of AEDs and proportion of seizure-free patients at two tertiary hospitals in Sweden.

METHOD

We retrospectively studied electronic medical records of all patients with a diagnosis of MS and seizures at Sahlgrenska university hospital and Uppsala university hospital. Clinical data were reviewed until 2017.

RESULTS

We identified a total of 62 MS patients with at least one seizure. Median age at the first seizure (before or after MS) was 41 years (range 0-80). The most common MS disease course at the first seizure was secondary progressive MS, the neurological disability was considerable, and most patients had several MRI lesions at their first seizure. The first EEG demonstrated epileptiform discharges in 38% and unspecific pathology in 40%. Current seizure status could be determined for 37 patients. Out of these, 46% had been seizure free for more than one year at last follow-up. The majority of patients (65%) were on monotherapy at last follow-up. Carbamazepine was the most commonly used first AED, with a retention rate of 52%. No individual AED was associated with a particularly high rate of seizure freedom. The most common reason for discontinuation of the first AED was side-effects.

CONCLUSION

Seizure freedom rates were low, perhaps indicating a need for higher ambitions in management. Side effects of AEDs may be a particular concern when treating epilepsy in patients with MS.

Neuroprotection by central nervous system remyelination: Molecular, cellular, and functional considerations

Oligodendrocytes and their myelin sheaths play an intricate role in axonal health and function. The prevalence of white matter pathology in a wide variety of central nervous system disorders has gained attention in recent years. Remyelination has therefore become a major target of therapeutic research, with the aim of protecting axons from further damage. The axon-myelin unit is elaborate, and demyelination causes profound changes in axonal molecular domains, signal transmission, and metabolism. Remyelination is known to restore some of these changes, but many of its outcomes remain unknown. Understanding how different aspects of the axon-myelin unit are restored by remyelination is important for making effective, targeted therapeutics for white matter dysfunction. Additionally, understanding how subtle deficits relate to axonal function during demyelination and remyelination may provide clues into the impact of myelin on neuronal circuits. In this review, we discuss the current knowledge of the neuroprotective effects of remyelination, as well as gaps in our knowledge. Finally, we propose systems with unique myelin profiles that may serve as useful models for investigating remyelination efficacy. © 2016 Wiley Periodicals, Inc.

A prospective study of conditions associated with multiple sclerosis in a cohort of 658 consecutive outpatients attending a multiple sclerosis clinic

The cause of multiple sclerosis (MS) remains unknown. It is largely regarded as being an inflammatory autoimmune disease and has been reported in association with other inflammatory/autoimmune diseases. We performed a prospective study in 658 consecutive patients diagnosed with MS attending our outpatient MS management clinic between June 2002 and June 2003. Prevalence of associated conditions in these patients was calculated and compared with values from population studies using chi-square tests, odds ratios and confidence intervals. The MS population had significantly increased rates of asthma, inflammatory bowel disease, type I diabetes mellitus, pernicious anaemia, autoimmune thyroid disease, uveitis, seronegative spondyloarthropathies, bipolar disorder and melanoma compared to the general population. Both T helper type 1 (Th1)-mediated and T helper type 2 (Th2)-mediated diseases were significantly increased compared to the general population. There were also interesting associations seen with polyglandular autoimmune syndrome and rare single case associations.

MS is associated with several other conditions. This work does not give evidence for the hypothesis that MS and atopy, reflecting Th1 and Th2 polarization, respectively, are mutually exclusive. Further work, ideally with a matched control population, is indicated.

Spinal-generated movement disorders: a clinical review

Spinal-generated movement disorders (SGMDs) include spinal segmental myoclonus, propriospinal myoclonus, orthostatic tremor, secondary paroxysmal dyskinesias, stiff person syndrome and its variants, movements in brain death, and painful legs-moving toes syndrome. In this paper, we review the relevant anatomy and physiology of SGMDs, characterize and demonstrate their clinical features, and present a practical approach to the diagnosis and management of these unusual disorders.

A systematic review of the incidence and prevalence of comorbidity in multiple sclerosis: overview

Background:

Comorbidity is an area of increasing interest in multiple sclerosis (MS).

Objective:

The objective of this review is to estimate the incidence and prevalence of comorbidity in people with MS and assess the quality of included studies.

Methods:

We searched the PubMed, SCOPUS, EMBASE and Web of Knowledge databases, conference proceedings, and reference lists of retrieved articles. Two reviewers independently screened abstracts. One reviewer abstracted data using a standardized form and the abstraction was verified by a second reviewer. We assessed study quality using a standardized approach. We quantitatively assessed population-based studies using the I² statistic, and conducted random-effects meta-analyses.

Results:

We included 249 articles. Study designs were variable with respect to source populations, case definitions, methods of ascertainment and approaches to reporting findings. Prevalence was reported more frequently than incidence; estimates for prevalence and incidence varied substantially for all conditions. Heterogeneity was high.

Conclusion:

This review highlights substantial gaps in the epidemiological knowledge of comorbidity in MS worldwide. Little is known about comorbidity in Central or South America, Asia or Africa. Findings in North America and Europe are inconsistent. Future studies should report age-, sex- and ethnicity-specific estimates of incidence and prevalence, and standardize findings to a common population.

A systematic review of the incidence and prevalence of sleep disorders and seizure disorders in multiple sclerosis

Background:

Several studies have suggested that comorbid neurologic disorders are more common than expected in multiple sclerosis (MS).

Objective:

To estimate the incidence and prevalence of comorbid seizure disorders and sleep disorders in persons with MS and to evaluate the quality of studies included.

Methods:

The PUBMED, EMBASE, Web of Knowledge, and SCOPUS databases, conference proceedings, and reference lists of retrieved articles were searched. Two reviewers independently screened abstracts to identify relevant articles, followed by full-text review of selected articles. We assessed included studies qualitatively and quantitatively (I² statistic), and conducted meta-analyses among population-based studies.

Results:

We reviewed 32 studies regarding seizure disorders. Among population-based studies the incidence of seizure disorders was 2.28% (95% CI: 1.11–3.44%), while the prevalence was 3.09% (95% CI: 2.01–4.16%). For sleep disorders we evaluated 18 studies; none were population-based. The prevalence ranged from 0–1.6% for narcolepsy, 14.4–57.5% for restless legs syndrome, 2.22–3.2% for REM behavior disorder, and 7.14–58.1% for obstructive sleep apnea.

Conclusion:

This review suggests that seizure disorders and sleep disorders are common in MS, but highlights gaps in the epidemiological knowledge of these conditions in MS worldwide. Other than central-western Europe and North America, most regions are understudied.

Multiple sclerosis and seizures: incidence and prevalence over 40 years

OBJECTIVES

The prevalence of multiple sclerosis (MS) is increasing worldwide. Epileptic seizures are more common in MS patients than in the general population. The aim of this study was to investigate changes in the prevalence and incidence of MS in a well-defined population over several decades and estimate the occurrence of epilepsy in the same cohort.

MATERIALS AND METHODS

Patients diagnosed with MS in the County of Vestfold, Norway in the period of 1983-2003 were identified. Point prevalence for MS and epilepsy was calculated for January 1, 2003. The average annual incidence rates were calculated in five-year periods from 1983 to 2002. These numbers were compared to previously published figures of prevalence from 1963 and incidence from 1953.

RESULTS

On prevalence day, we identified 364 patients diagnosed with MS living in Vestfold. Thus, the prevalence increased from 61.6/100,000 in 1963 to 166.8/100,000 in 2003. In the period 1983-2002, the annual incidence fluctuated between 4.2 and 7.3/100,000/year (mean 4.5, 95% CI 3.6 - 5.5). In 2003, the portion of MS patients with epileptic seizures was 7.4%, compared to 2.9% in 1963.

CONCLUSIONS

During the 40 years follow-up of this population, the incidence of MS was stable, while the prevalence of MS and the share of MS patients with epileptic seizures increased. Compared to the general population, the risk of having active epilepsy was increased fourfold. We assume that this is a consequence of an increased survival in MS patients.

Epileptic seizures in multiple sclerosis: a population-based survey in Iran

No large population-based survey has until now been carried out on the linkage of epilepsy (EP) and multiple sclerosis (MS) either in the middle-east or in Asia. In this retrospective population-based study (April 2003 to July 2010) on the total Isfahan cohort of 3,522 Iranian MS patients, we looked for EP/MS patients and compared their features with 1,665 non-EP/MS cases. We identified 105 cases, though, 24 were excluded for an implausible EP/MS link. Among 81 (2.3 %) eligible cases, EP occurred (1) within a mean duration of 5.6 ± 5.4 years after the development of MS in 64 cases (79 %); (2) at MS onset as the presenting symptom in five cases (6.2 %); and, (3) by a mean duration of 4.3 ± 4.3 years prior to onset of MS in 12 patients (14.8 %). The overall mean ages at MS onset and at the first seizure episode were 28.5 ± 11.2 years and 32.5 ± 14.0 years, respectively. Regarding the age at onset of MS, 12.3 % of EP/MS patients were classified as early-onset; 81.5 % as adult-onset; and 6.2 % as late-onset. Such frequencies were statistically different (P < 0.0001) from those of the 1,665 control non-EP/MS patients (5.9; 93.0 and 1.1 %, respectively). Regarding the pattern of MS, EP/MS patients were classified as relapsing-remitting, secondary progressive, and primary progressive in 60.5, 25.9, and 13.6 %, respectively. This configuration differed (P < 0.0001) from that of non-EP patients (87.9; 6.3 and 5.7 %, respectively). Our results are suggestive of differences between EP/MS and non-EP/MS cases as regards the proportion of MS patterns and age-at-onset classifications.

Enhancing neural transmission in multiple sclerosis (4-aminopyridine therapy)

Enhancing neural transmission by improving axonal conduction and synaptic neurotransmitter release is a novel strategy to improve symptoms in multiple sclerosis. Dalfampridine (4-aminopyridine extended-release) is a first-in-class medication that targets the damaged nervous system through blockage of voltage-gated potassium channels. Through a series of clinical trials, dalfampridine (dosed at 10 mg twice daily) has been found to improve walking speed by approximately 25 % on average in one third of individuals with multiple sclerosis regardless of disease stage. Furthermore, it significantly improves patients' perception of their ambulatory disability and may improve lower extremity strength. Given the mechanism of action, the most serious adverse effect is its pro-convulsant property, which occurs more frequently at high serum concentrations. The most common adverse events include increased falls, urinary tract infections, dizziness, insomnia, and headaches. Despite these potential side-effects, the vast majority of individuals who derive benefit continue on the treatment. The exact mechanism of action is uncertain, as is the reason for response variability. The medication serves as proof-of-concept that targeting axonal transmission can improve disability in multiple sclerosis.

Epileptic seizures in Japanese patients with multiple sclerosis and neuromyelitis optica

PURPOSE

To examine the incidence and clinical features of epileptic seizures in Japanese patients with multiple sclerosis (MS) and neuromyelitis optica (NMO).

METHODS

We reviewed medical records of all patients who visited the Neurology Clinic in Utano National Hospital between January and December, 2009, and enrolled 63 MS patients who fulfilled the McDonald criteria (2005) (mean age, 41.1 years) and 31 NMO patients who fulfilled the Wingerchuk criteria (2006) (mean age, 44.6 years). Patients with a history of epileptic seizures were selected and their clinical features were obtained.

RESULTS

Four MS patients (6.3%; 2 men and 2 women; mean age, 32.5 years) and 4 NMO patients (12.9%; 4 women; mean age, 36.0 years) had epileptic seizures. Disease onset age of MS patients with seizures was significantly younger than those without seizures by 13.1 years, and Expanded Disability Status Scale of NMO patient with seizures was significantly higher than those without seizures by 2.2. All 8 patients showed brain lesions on magnetic resonance imaging and 2 MS patients had tumefactive demyelinating lesions. Electroencephalography showed interictal epileptiform discharges in 5 patients. Seizure types of 6 patients were recognized as partial seizures based on clinical semiology. All patients responded to antiepileptic therapy well. In both MS and NMO, there were both seizures with and without concurrent relapse.

CONCLUSIONS

Similar to MS, NMO patients possibly have higher risk to develop epileptic seizures than general population.

Clinical correlates of grey matter pathology in multiple sclerosis

Traditionally, multiple sclerosis has been viewed as a disease predominantly affecting white matter. However, this view has lately been subject to numerous changes, as new evidence of anatomical and histological changes as well as of molecular targets within the grey matter has arisen. This advance was driven mainly by novel imaging techniques, however, these have not yet been implemented in routine clinical practice. The changes in the grey matter are related to physical and cognitive disability seen in individuals with multiple sclerosis. Furthermore, damage to several grey matter structures can be associated with impairment of specific functions. Therefore, we conclude that grey matter damage - global and regional - has the potential to become a marker of disease activity, complementary to the currently used magnetic resonance markers (global brain atrophy and T2 hyperintense lesions). Furthermore, it may improve the prediction of the future disease course and response to therapy in individual patients and may also become a reliable additional surrogate marker of treatment effect.

Meningeal and cortical grey matter pathology in multiple sclerosis

Although historically considered a disease primarily affecting the white matter of the central nervous system, recent pathological and imaging studies have established that cortical demyelination is common in multiple sclerosis and more extensive than previously appreciated. Subpial, intracortical and leukocortical lesions are the three cortical lesion types described in the cerebral and cerebellar cortices of patients with multiple sclerosis. Cortical demyelination may be the pathological substrate of progression, and an important pathologic correlate of irreversible disability, epilepsy and cognitive impairment. Cortical lesions of chronic progressive multiple sclerosis patients are characterized by a dominant effector cell population of microglia, by the absence of macrophagic and leukocytic inflammatory infiltrates, and may be driven in part by organized meningeal inflammatory infiltrates. Cortical demyelination is also present and common in early MS, is topographically associated with prominent meningeal inflammation and may even precede the appearance of classic white matter plaques in some MS patients. However, the pathology of early cortical lesions is different than that of chronic MS in the sense that early cortical lesions are highly inflammatory, suggesting that neurodegeneration in MS occurs on an inflammatory background and raising interesting questions regarding the role of cortical demyelination and meningeal inflammation in initiating and perpetuating the disease process in early MS.

Gray matter imaging in multiple sclerosis: what have we learned?

At the early onset of the 20^th century, several studies already reported that the gray matter was implicated in the histopathology of multiple sclerosis (MS). However, as white matter pathology long received predominant attention in this disease, and histological staining techniques for detecting myelin in the gray matter were suboptimal, it was not until the beginning of the 21^st century that the true extent and importance of gray matter pathology in MS was finally recognized. Gray matter damage was shown to be frequent and extensive, and more pronounced in the progressive disease phases. Several studies subsequently demonstrated that the histopathology of gray matter lesions differs from that of white matter lesions. Unfortunately, imaging of pathology in gray matter structures proved to be difficult, especially when using conventional magnetic resonance imaging (MRI) techniques. However, with the recent introduction of several more advanced MRI techniques, the detection of cortical and subcortical damage in MS has considerably improved. This has important consequences for studying the clinical correlates of gray matter damage. In this review, we provide an overview of what has been learned about imaging of gray matter damage in MS, and offer a brief perspective with regards to future developments in this field.

Symptomatic therapy in multiple sclerosis: a review for a multimodal approach in clinical practice

As more investigations into factors affecting the quality of life of patients with multiple sclerosis (MS) are undertaken, it is becoming increasingly apparent that certain comorbidities and associated symptoms commonly found in these patients differ in incidence, pathophysiology and other factors compared with the general population. Many of these MS-related symptoms are frequently ignored in assessments of disease status and are often not considered to be associated with the disease. Research into how such comorbidities and symptoms can be diagnosed and treated within the MS population is lacking. This information gap adds further complexity to disease management and represents an unmet need in MS, particularly as early recognition and treatment of these conditions can improve patient outcomes. In this manuscript, we sought to review the literature on the comorbidities and symptoms of MS and to summarize the evidence for treatments that have been or may be used to alleviate them.

Systemic and neurologic autoimmune disorders associated with seizures or epilepsy

In this article, we review the incidence and significance of seizures in well-established autoimmune disorders, including multiple sclerosis (MS), diabetes mellitus, celiac disease, thyroid disease, and systemic lupus erythematosus (SLE). The five following presentations discuss the incidence and possible pathogenesis of epilepsies that are found in these well-known autoimmune conditions. There is a large body of evidence describing the clinical presentation of seizures with MS and SLE, and showing that refractory epilepsy can complicate these already challenging disorders. However, the mechanisms involved are complex and generally not well understood. Neurologic syndromes, including seizure disorders, can also be a feature of celiac disease (CD) or subclinical CD, sometimes associated with cerebral calcification. The association between type-1 diabetes mellitus (T1DM) and epilepsy is unclear and requires more definitive epidemiologic analysis, despite the fact that antibodies to glutamic acid decarboxylase may provide a link between the two conditions. The association between thyroid disorders and encephalopathies, often termed Hashimoto's encephalopathy, is well known but the pathogenic significance of antithyroid antibodies in this condition is still debated. In general, the relationships between autoimmune mechanisms and seizures in these conditions are unclear; the seizures are likely to be caused by a variety of mechanisms, including ischemia, neuronal damage, and specific and nonspecific immunity.

[Neuroimaging of multiple sclerosis in children]

There is an increasing appreciation that multiple sclerosis (MS) can affect children. Up to 10% of MS patients experience their first symptoms before the age of 16. The natural history and magnetic resonance imaging of MS in child-hood differ from those observed in adult patients. The differential diagnosis of MS in children should also encompass some paediatric diseases. Recently, the diagnostic criteria for MS in children were published. Due to the high frequency of relapses and the risk of disability at a young age, early diagnosis and treatment of MS in children is very important. This work presents recent data regarding epidemiology, pathogenesis and diagnosis of MS in children, including the role of neuroimaging in the diagnosis of childhood multiple sclerosis.

Imaging the tip of the iceberg: visualization of cortical lesions in multiple sclerosis

BACKGROUND

Cortical lesions (CLs) occur frequently in multiple sclerosis (MS), but only few CLs are observed on conventional magnetic resonance imaging (MRI). Why some CLs are visible and others are not is currently unknown. Here, we investigated whether CLs that are visible on conventional MRI differ from MRI-invisible CLs in terms of underlying histopathology and quantitative MRI (qMRI) measures.

METHODS

A total of 16 brain slices from 10 patients with chronic MS were analysed histopathologically and with conventional and qMRI. A region-of-interest approach was used to compare MRI-visible CLs with MRI-invisible CLs.

RESULTS

Although under-powering cannot be completely excluded in this study, MRI-visible CLs did not seem to differ from MRI-invisible CLs in terms of histopathology or qMRI measures. They were, however, significantly larger than their invisible counterparts (mean 13.3 ± 1.7 mm(2) versus 6.9 ± 1.3 mm(2); p = 0.001). Furthermore, the number of MRI-visible lesions correlated with the overall number of CLs in the brain slice (r = 0.96, p < 0.01) and with the overall percentage of demyelination (r = 0.78, p < 0.01) per hemispheric brain slice.

CONCLUSION

MRI visibility of CLs is determined by lesion size, and not by any distinctive underlying pathology. Visible CLs are associated with a higher total cortical lesion load, which suggests that when CLs in patients with MS become detectable on MRI, they merely represent 'the tip of the pathological iceberg'.

Multiple sclerosis and epileptic seizures

Background: The association between epilepsy and multiple sclerosis (MS) is not a coincidence.

Objective: Our objective was to compare MS patients with or without history of seizures.

Methods: In a population of 5041 MS patients, we identified 102 (2%) patients with epileptic seizures. In 67 patients (1.3%), epileptic seizure could not be explained by any cause other than MS.

Results: In these 67 patients, the median age at occurrence of the first epileptic seizure was 33 years. Epilepsy was the initial clinical manifestation of MS in seven patients. In total, 62 patients (92.5%) presented only one or a few seizures, and 18 patients (27%) presented at least one episode of status epilepticus, fatal in two. Compared with MS patients without epilepsy, there was no difference in gender, type of MS course and time from onset of MS to the progressive phase. Conversely, the median age at MS onset was earlier (25.0 years vs. 30, p < 0.0001) and there was a trend for a shorter time from MS onset to non-reversible disability.

Conclusions: Our study confirms an increased risk of epileptic seizures in MS patients. It underlines that seizures may be the first observable symptom in MS and the frequency and seriousness of status epilepticus.

Gray matter pathology in (chronic) MS: modern views on an early observation

Involvement of the gray matter (GM) in the pathology of multiple sclerosis (MS) was already recognized in the early days of MS research, but the detection of (cortical) GM lesions under the microscope and with magnetic resonance imaging (MRI) techniques was initially suboptimal and could only recently be enhanced. The visualization of GM lesions in vivo opens new doors for studies focusing on clinical, especially cognitive, effects of GM pathology, as well as for monitoring of neuroprotective treatment. However, so far little is known about what causes GM pathology. In this review, several pathogenetic mechanisms will be discussed, affecting the MS brain both from the 'outside-in' and from the 'inside-out'. Also, the use and reliability of MRI atrophy measures as a monitoring tool for GM damage in the therapeutic setting will be reviewed.

3D MPRAGE improves classification of cortical lesions in multiple sclerosis

BACKGROUND

Gray matter lesions are known to be common in multiple sclerosis (MS) and are suspected to play an important role in disease progression and clinical disability. A combination of magnetic resonance imaging (MRI) techniques, double-inversion recovery (DIR), and phase-sensitive inversion recovery (PSIR), has been used for detection and classification of cortical lesions. This study shows that high-resolution three-dimensional (3D) magnetization-prepared rapid acquisition with gradient echo (MPRAGE) improves the classification of cortical lesions by allowing more accurate anatomic localization of lesion morphology.

METHODS

11 patients with MS with previously identified cortical lesions were scanned using DIR, PSIR, and 3D MPRAGE. Lesions were identified on DIR and PSIR and classified as purely intracortical or mixed. MPRAGE images were then examined, and lesions were re-classified based on the new information.

RESULTS

The high signal-to-noise ratio, fine anatomic detail, and clear gray-white matter tissue contrast seen in the MPRAGE images provided superior delineation of lesion borders and surrounding gray-white matter junction, improving classification accuracy. 119 lesions were identified as either intracortical or mixed on DIR/PSIR. In 89 cases, MPRAGE confirmed the classification by DIR/PSIR. In 30 cases, MPRAGE overturned the original classification.

CONCLUSION

Improved classification of cortical lesions was realized by inclusion of high-spatial resolution 3D MPRAGE. This sequence provides unique detail on lesion morphology that is necessary for accurate classification.

Seizures in patients with multiple sclerosis: epidemiology, pathophysiology and management

Seizures have been recognized to occur in multiple sclerosis (MS) since early descriptions of the disease. Various studies have attempted to determine the incidence and prevalence of seizures in MS; although they differ in the reported prevalence, seizures do appear to be more common in MS cohorts than in the general population. The pathological underpinning of seizures in MS remains indeterminate. Cortical and subcortical demyelination and inflammation may explain the increased frequency of seizures in MS, although this hypothetical correlation remains to be proven. Management of seizures in MS is similar to the management of seizures in other patients. Consideration of the underlying neurological deficits related to MS may be necessary, and dosages of antiepileptic drugs should be adjusted if increased sensitivity to the adverse effects of these agents or interaction with other centrally acting medications is suspected. The prognosis of epilepsy in patients with MS remains uncertain, with some studies suggesting a more favourable prognosis than others.

Does high-field MR imaging improve cortical lesion detection in multiple sclerosis?

OBJECTIVE

Cortical lesions in multiple sclerosis (MS) are notoriously difficult to visualize with standard MR imaging (MRI) techniques. However, the use of higher field-strengths with intrinsically higher signal-to-noise, which can partly be used to increase spatial resolution, may improve cortical lesion detection. Therefore, in this post mortem study, the sensitivity of high field-strength MRI (4.7 T) for cortical lesions was investigated, and compared to that of standard field-strength (1.5 T).

METHODS

At 1.5 T, dual-echo T2-weighted spin-echo, as well as 3D-FLAIR images of seventeen formalin-fixed coronal MS and four control hemispheres were acquired. At 4.7 T, the same specimens were imaged with a mainly proton-density (PD)- weighted sequence. Proteolipid protein (PLP)-stained tissue sections (10 microm) of the same brain slices were matched to the corresponding MR images, and cortical lesions were scored on all three MR sequences (blinded to histology) and in tissue sections (blinded to MRI). Sensitivity of the sequences for four cortical lesion types was calculated. Additionally, an unblinded, retrospective MR scoring was performed.

RESULTS

Sensitivity for purely intracortical lesions (histological lesion types II, III, and IV; n = 128) was below 10 % for both 1.5 T and 4.7 T MRI, while mixed gray matter-white matter (type I) lesions (n = 5) were detected in four out of five cases. All lesion counts increased upon retrospective (unblinded) scoring. However, up to 80% of the intracortical lesions still remained undetected.

CONCLUSIONS

MRI sensitivity for post mortem detection of cortical lesions is low, even when a higher field-strength was used. It varies, however, for different subtypes of cortical lesions.

Treatment strategies after a single seizure : rationale for immediate versus deferred treatment

What is the rationale for the treatment of an epileptic seizure? More specifically, should a first seizure be treated as soon as it is diagnosed or should one defer treatment until a second seizure occurs? Several studies indicate that the risk of a second (unprovoked) seizure is <50%, but studies vary in methodology and most have reviewed outcome in children only. Also, many patients were maintained on antiepileptic drugs (AEDs) during these studies, meaning that the risk for seizure recurrence was perhaps underestimated compared with the risk if untreated. Most neurologists recommend waiting for a second seizure in order to avoid complications of medications that might prove to be unnecessary. Several large studies show that delaying treatment until a second seizure occurs does not worsen the course of epilepsy or likelihood of eventual seizure control. Seizures attributable to an acute illness ('acute symptomatic', provoked seizures) usually resolve with treatment of the underlying illness and thus long-term AEDs are often unwarranted. Nevertheless, seizures arising in certain circumstances are more likely to recur and there are special considerations for patients with strokes, tumours, infections and dementia, and also after head injury or neurosurgery. Patient preferences with regard to risk and benefit also enter into the decision on whether to initiate AED treatment after a single seizure.

Gray and normal-appearing white matter in multiple sclerosis: an MRI perspective

Besides focal white matter lesions, multiple sclerosis brain tissue also displays abnormalities in the gray matter and the normal-appearing white matter. Recent advances in magnetic resonance imaging studies of both types of tissue are discussed. Herein, normal-appearing white matter abnormalities are being found in quantitative magnetic resonance investigations, consistent with a limited degree of axonal damage and/or demyelination, and an increase of glial cells, but the specific nature of the histopathological changes underlying the quantitative magnetic resonance abnormalities remains unclear. Gray matter studies have demonstrated that much of the disease process remains undetected by conventional magnetic resonance imaging. Although newly developed techniques, such as 3D double-inversion recovery, may greatly improve detection of cortical pathology, it remains important to investigate the resultant effects on the cortical tissue alongside this, by studying integrity of normal-appearing cortical tissue through quantitative magnetic resonance studies, as well as the net neurodegenerative effect through measurements of cortical thickness and cortical atrophy (rates). To improve our understanding of normal-appearing white and gray matter changes, their mutual relations, and their relations to clinical changes, further in vivo magnetic resonance imaging studies are required. Specifically, it is proposed that more spatially specific investigations, ideally utilizing subject-specific anatomical information from, for example, diffusion fiber-tracking techniques, could be used to gain more insight into the relations between normal-appearing white matter changes, cortical changes, magnetic resonance visible focal-lesions, and physical and cognitive deficits.

Spinal cord gray matter demyelination in multiple sclerosis-a novel pattern of residual plaque morphology

The extent and pattern of gray matter (GM) demyelination in the spinal cord in multiple sclerosis (MS) has not been examined in detail. Human autopsy material was obtained from 36 MS cases and 12 controls. Transverse sections were taken from five levels of the spinal cord (upper cervical, lower cervical, upper thoracic, lower thoracic and lumbar levels) and the extent of GM and white matter (WM) demyelination evaluated using proteolipid protein immunohistochemistry (IHC). The proportion of the GM that was demyelinated (33%) was significantly greater than the proportion of demyelinated WM (20%) (P < 0.0001). Similarly, demyelination was more extensive in the GM than in the WM at each of the five cord levels. The extent of GM demyelination was not significantly different between the five cord levels while WM demyelination was greatest at the upper cervical level. Morphologically, the borders of a proportion of the GM plaques show a strict respect for the GM/WM boundary. We demonstrate that extensive demyelination occurs in the GM of the spinal cord in MS. Myelin protein IHC reveals a novel pattern of residual plaque morphology challenging previous work suggesting that MS plaques display a total disregard for anatomical boundaries.

Clinical characteristics of cortical multiple sclerosis

There are several articles in this special issue in which authors eloquently describe neurobehavioural and cognitive complications of multiple sclerosis with relevant neuropsychological assessments and neuroimaging findings. However behavioural and cognitive presentation of multiple sclerosis remains poorly understood. Two years ago, we reported a series of patients with multiple sclerosis who presented with neurobehavioural symptoms and had neuropsychological deficits consistent with cortical dysfunction. Based on previous case reports, pathological studies of cerebral cortex in multiple sclerosis and advanced neuroimaging studies we suggested that neurobehavioural presentation of multiple sclerosis represents a new variant called "cortical multiple sclerosis". The condition is characterised by predominant or exclusive cortical pathology presenting with neurobehavioural symptoms, such as depression, amnesia or distinct cortical syndromes. Since the publication of our report, there has been further neuroimaging and neuropathological findings that further supported the above concept. In addition, observation of more patients with this condition helped us to formulate a logical approach in the detection of these patients. This article focuses on their clinical characteristics.