Clinical characteristics of cortical multiple sclerosis

Cognitive Decline in Older People with Multiple Sclerosis—A Narrative Review of the Literature

Several important questions regarding cognitive aging and dementia in older people with multiple sclerosis (PwMS) are the focus of this narrative review: Do older PwMS have worse cognitive decline compared to older people without MS? Can older PwMS develop dementia or other neurodegenerative diseases such as Alzheimer’s disease (AD) that may be accelerated due to MS? Are there any potential biomarkers that can help to determine the etiology of cognitive decline in older PwMS? What are the neural and cellular bases of cognitive aging and neurodegeneration in MS? Current evidence suggests that cognitive impairment in MS is distinguishable from that due to other neurodegenerative diseases, although older PwMS may present with accelerated cognitive decline. While dementia is prevalent in PwMS, there is currently no consensus on defining it. Cerebrospinal fluid and imaging biomarkers have the potential to identify disease processes linked to MS and other comorbidities—such as AD and vascular disease—in older PwMS, although more research is required. In conclusion, one should be aware that multiple underlying pathologies can coexist in older PwMS and cause cognitive decline. Future basic and clinical research will need to consider these complex factors to better understand the underlying pathophysiology, and to improve diagnostic accuracy.

The relevance of cortical lesions in patients with multiple sclerosis

BACKGROUND

Recent studies suggest that cortical lesions in multiple sclerosis (MS) substantially contribute to clinical disease severity. The present study aimed at investigating clinical, neuroanatomical, and cognitive correlates of these cortical lesions with a novel approach, i.e. by comparing two samples of relapsing-remitting multiple sclerosis (RRMS) patients, one group with and the other without cortical lesions.

METHODS

High-resolution structural MRI was acquired from 42 RRMS patients and 43 controls (HC). The patient group was dichotomized based on the presence versus absence of DIR-hyperintense cortex-involving lesions, resulting in a cortical lesion group (CL, n = 32) and a non-cortical lesion group (nCL, n =10). Cognitive functioning was assessed in all participants with a comprehensive neuropsychological battery, covering mnestic, executive, and attentional functions.

RESULTS

Highest densities of cortical lesions in the CL group were observed in the bilateral parahippocampal gyrus. Relative to HC, patients with cortical lesions - but not those without - showed significant global cortical thinning and mnestic deficits. The two patient groups did not differ from each other regarding demographic and basic disease characteristics such as EDSS scores.

CONCLUSION

The appearance of cortical lesions in MS patients is associated with cortical thinning as well as mnestic deficits, which might be key characteristics of a 'cortically dominant' MS subtype.

Cortical relapses in multiple sclerosis

Background:

Multiple sclerosis (MS) is a white and grey matter disease of the central nervous system (CNS). It is recognized that cortical damage (i.e. focal lesions and atrophy) plays a role in determining the accumulation of physical and cognitive disability that is observed in patients with progressive MS. To date, an association of cortical lesions with clinical relapses has not been described.

Results:

We report clinical and magnetic resonance imaging (MRI) findings of five relapsing–remitting MS (RRMS) patients who had clinical relapses characterized by the acute appearance of cortical symptoms, due to the development of large, snake-like, cortical inflammatory lesions. Symptoms were: acute Wernicke’s aphasia mimicking stroke; agraphia with acalculia, not associated to a motor deficit nor linguistic disturbance; hyposthenia of the left arm, followed by muscle twitching of the hand, spreading to arm and face; acute onset of left lower limb paroxysmal hypertonia; and temporal lobe status epilepticus, with psychotic symptoms.

Conclusions:

Cortical relapses may occur in MS. MRI examination in MS should include sequences, such as double inversion recovery (DIR) or phase sensitive inversion recovery (PSIR), that are aimed at visualizing cortical lesions, especially in the presence of symptoms of cortical dysfunction. Our observation further stresses and extends the clinical relevance of cortical pathology in MS.

Late-onset multiple sclerosis presenting with cognitive dysfunction and severe cortical/infratentorial atrophy

Objective:

Although cognitive dysfunction is a relevant aspect of multiple sclerosis (MS) from the earliest disease phase, cognitive onset is unusual thus jeopardizing early and accurate diagnosis. Here we describe 12 patients presenting with cognitive dysfunction as primary manifestation of MS with either mild or no impairment in non-cognitive neurological domains.

Methods:

Twelve patients with cognitive onset who were subsequently diagnosed with MS (CI-MS) were included in this retrospective study. Twelve cognitively normal MS patients (CN-MS), 12 healthy controls and four patients having progressive supranuclear palsy (PSP) served as the reference population.

Results:

Ten CI-MS patients had progressive clinical course and all patients had late disease onset (median age = 49 years; range = 40–58 years). Among cognitive functions, frontal domains were the most involved. Compared to CN-MS and healthy controls, significant cortical and infratentorial atrophy characterized CI-MS patients. Selective atrophy of midbrain tegmentum with relative sparing of pons, known as “The Hummingbird sign,” was observed in eight CI-MS and in three PSP patients.

Discussion:

Our observation suggests that MS diagnosis should be taken into consideration in case of cognitive dysfunction, particularly when associated with slowly progressive disease course and severe cortical, cerebellar and brainstem atrophy even in the absence of other major neurological symptoms and signs.

Patterns of regional gray matter and white matter atrophy in cortical multiple sclerosis

We investigated the patterns of regional distribution of focal lesions, white matter (WM) and gray matter (GM) atrophy in patients with cortical (cort) MS in comparison to classical (c) MS patients. Nine cort-MS, nine c-MS and nine age-matched healthy controls (HC) underwent a brain MRI exam, including FLAIR and high-resolution T1-weighted scans. MS patients underwent neurological and neuropsychological assessment. Between-group differences of GM and WM volumes and their correlations with neuropsychological performances were assessed with voxel-based morphometry. FLAIR and T1 lesion probability maps (LPMs) were also obtained. Performance at neuropsychological tests was worse in cort-MS than in c-MS patients. Compared to HC, MS patients had a distributed pattern of GM and WM atrophy. No GM/WM area was more atrophic in c-MS vs cort-MS patients. Compared to c-MS, cort-MS patients experienced GM atrophy of frontal-temporal-parietal areas and cingulate cortex and WM atrophy of the cingulum bundle, bilateral cerebral peduncles, right inferior longitudinal fasciculus and left superior longitudinal fasciculus. FLAIR and T1 LPMs did not differ between c-MS vs cort-MS patients. A higher susceptibility to neurodegenerative processes in key brain regions known to be related to cognitive functions is likely to underlie the clinical manifestations of cort-MS.

Differential diagnosis of white matter lesions: Nonvascular causes-Part II

The knowledge of characteristic lesion patterns is important in daily practice imaging, as the radiologist increasingly is required to provide precise differential diagnosis despite unspecific clinical symptoms like cognitive impairment and missed elaborated neurological workup. This part II dealing with nonvascular white matter changes of proven cause and diagnostic significance aimed to assist the evaluation of diseases exhibiting lesions exclusively or predominantly located in the white matter. The etiologies commented on are classified as follows: (a) toxic-metabolic, (b) leukodystrophies and mitochondriopathies, (c) infectious, (d) neoplastic, and (e) immune mediated. The respective mode of lesion formation is characterized, and typical radiological findings are displayed. More or less symmetrical lesion patterns on the one hand as well as focal and multifocal ones on the other are to be analyzed with reference to clinical data and knowledge of predilection sites characterizing major disease categories. Complementing spinal cord imaging may be useful not only in acute and relapsing demyelinating diseases but in certain leukodystrophies as well. In neuromyelitis optica (NMO), the detection of a specific antibody and some recently published observations may lead to a new understanding of certain deep white matter lesions occasionally complicating systemic autoimmune disease.

Gray matters in multiple sclerosis: cognitive impairment and structural MRI

Multiple sclerosis (MS) is an immune-mediated disease affecting central nervous system (CNS). Although MS is classically considered a white matter (WM) disease, the involvement of gray matter (GM) in the pathogenic process has been confirmed by pathology studies and MRI studies. Impairment of cognitive domains such as memory, mental processing speed, attention, and executive function can occur from the early stage of the disease and tends to worsen over time, despite stable physical symptoms. WM demyelination is moderately correlated with CI, suggesting that probably WM abnormalities alone cannot fully explain the extent of clinical symptoms in MS, including CI. Several MRI techniques have shown the involvement of GM in MS and the association between GM damage, physical disability, and CI. The aim of this review is to provide an overview of CI and GM damage assessed by structural brain MRI.

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.

Multiple Sclerosis-Related Dementia: Relatively Rare and Often Misunderstood

MS-related dementia is an under-recognised and misunderstood aspect of MS. It is relatively rare, occurring in approximately 10% of people with MS, while cognitive impairment in general occurs in 43% or more of people with MS. MS-related dementia is hard to detect on the basis of short social interactions or clinical interviews alone. There are very few clinically relevant scientific articles on this topic to help guide the management and support of people with MS-related dementia. This article was written in a preliminary attempt to address this problem: to describe the clinical presentation and characteristics of MS-related dementia, to alert health professionals to the sensitivities surrounding the use of dementia terminology within the MS community, and to outline the limited nature of the information, advice and support resources currently available in Australia for these middle-aged people with dementia.

Acute severe memory impairment as a presenting symptom of multiple sclerosis: a clinical case study with 3D double inversion recovery MR imaging

We present the case of a 21-year-old woman with acute memory impairment. It was initially not recognized as organic in nature. Repeated neuropsychological testing confirmed severely disturbed encoding and recall. Three-dimensional double inversion recovery (3D-DIR) MRI confirmed hippocampal and cortical lesions. Further clinical symptoms, visual evoked potential and MRI suggested a diagnosis of multiple sclerosis (MS). The amnestic syndrome has remained for 5 years. This case illustrates that MS can present with acute cortical symptoms which can be difficult to recognize. The hippocampus can be acutely affected and DIR MRI imaging can help to demonstrate cortical lesions that explain the clinical picture.

Magnetic resonance evidence of cortical onset of multiple sclerosis

BACKGROUND

Despite clinical symptoms and signs of central nervous system dysfunction, conventional magnetic resonance imaging (MRI) of the brain and spinal cord may appear normal in multiple sclerosis (MS) at clinical onset.

OBJECTIVE

To demonstrate cortical pathology, namely the presence of cortical lesions (CLs) in patients with symptoms/signs suggestive of MS but having normal appearing white matter (WM) on MRI.

METHODS

CLs were disclosed by double inversion recovery (DIR) MRI sequence. The final diagnosis of MS was achieved by the demonstration of the dissemination in space and time of WM lesions, and the absence of a better explanation of symptoms/signs, according to the established international diagnostic criteria.

RESULTS

We describe four patients with MS, in which CLs were observed by DIR months/years before the MRI evidence of inflammatory lesions in the WM.

INTERPRETATION

We suggest that, at least in some patients with MS, the pathological process underlying MS starts in the cortex. DIR sequence should be included in the MRI examination of suspected patients with MS with normal conventional MRI sequences at clinical onset. CLs should be evaluated for their inclusion in the MRI diagnostic criteria for MS.

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.

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.

Multiple sclerosis and behavior

Multiple sclerosis (MS) is one of the most frequently seen neurological causes of progressive disability in early to middle adulthood. The disease is variable in its presentation and course, affects roughly 100-300 per 100,000 persons within the United States alone, and is slightly more common among females than males. MS places substantial burdens on patients, families, and caregivers. It negatively affects cognitive abilities and psychiatric functioning, and can add a notably deleterious effect on a patient's quality of life. This chapter reviews the recent literature on the behavioral manifestations of MS. Cognitive domains discussed include executive functioning, processing speed, attention, learning and memory, language functioning, and visual spatial processing. Some attention will also be paid to differential diagnosis and the cognitive effects of treatment. Psychiatric manifestations are also discussed, including symptoms of depression, bipolar disorder, euphoria, pathological laughter and crying, and psychosis, as well as maladaptive personality traits. Finally, the chapter concludes with a discussion of the effects of MS on quality of life including such areas as fatigue, sexual dysfunction, pain, employment, and cognitive functioning.

Multiple Sklerose — eine neuroimmunendokrine Erkrankung

Die Multiple Sklerose (MS) ist eine chronische, entzündlich-demyelinisierende Erkrankung des Zentralnervensystems (ZNS), betrifft also Gehirn und Rückenmark, wobei heute eine autoimmune Ätiologie allgemein angenommen wird. Sie ist die häufigste Entmarkungserkrankung des ZNS in Nordeuropa und Nordamerika (Prävalenz 1:1000) und die häufigste chronisch-neurologische Erkrankung, die bei jungen Erwachsenen zu bleibender Behinderung führt.