Conduction aphasia in multiple sclerosis: a case report with MRI findings

Language impairments in people with autoimmune neurological diseases: A scoping review

INTRODUCTION

Autoimmune neurological diseases (ANDs) are a specific type of autoimmune disease that affect cells within the central and peripheral nervous system. ANDs trigger various physical/neuropsychiatric symptoms. However, language impairments in people with ANDs are not well characterized. Here we aimed to determine the kinds of language impairment that most commonly emerge in 10 ANDs, the characteristics of the patients (demographic, neurological damage), and the assessment methods used.

METHODS

We followed the PRISMA Extension for Scoping Reviews (PRISMA-ScR). PubMed and Google Scholar were searched. We used a list of search terms containing 10 types of ANDs (e.g., multiple sclerosis, acute disseminated encephalomyelitis) in combination with the terms aphasia, dysphasia, fluency, language, listening, morphology, phonology, pragmatics, reading, semantics, speaking, syntax, writing. The reference lists and citations of the relevant papers were also investigated. The type of AND, patient characteristics, neurological damage and examination technique, language tests administered, and main findings were noted for each study meeting the inclusion criteria.

RESULTS

We found 171 studies meeting our inclusion criteria. These comprised group studies and case studies. Language impairments differed largely among types of ANDs. Neurological findings were mentioned in most of the papers, but specific language tests were rarely used.

CONCLUSIONS

Language symptoms in people with ANDs are commonly reported. These are often not full descriptions or only focus on specific time points in the course of the disease. Future research needs to assess specific language functions in people with ANDs and relate their language impairments to brain damage at different stages of disease evolution.

Topological Alterations of the Structural Brain Connectivity Network in Children with Juvenile Neuronal Ceroid Lipofuscinosis

BACKGROUND AND PURPOSE

We used diffusion MR imaging to investigate the structural brain connectivity networks in juvenile neuronal ceroid lipofuscinosis, a neurodegenerative lysosomal storage disease of childhood. Although changes in conventional MR imaging are typically not visually apparent in children aged <10 years, we previously found significant microstructural abnormalities by using diffusion MR imaging. Therefore, we hypothesized that the structural connectivity networks would also be affected in the disease.

MATERIALS AND METHODS

We acquired diffusion MR imaging data from 14 children with juvenile neuronal ceroid lipofuscinosis (mean ± SD age, 9.6 ± 3.4 years; 10 boys) and 14 control subjects (mean ± SD age, 11.2 ± 2.3 years; 7 boys). A follow-up MR imaging was performed for 12 of the patients (mean ± SD age, 11.4 ± 3.2 years; 8 boys). We used graph theoretical analysis to investigate the global and local properties of the structural brain connectivity networks reconstructed with constrained spherical deconvolution-based whole-brain probabilistic tractography.

RESULTS

We found significantly increased characteristic path length (P = .003) and decreased degree (P = .003), which indicated decreased network integration and centrality in children with juvenile neuronal ceroid lipofuscinosis. The findings were similar for the follow-up MR imaging, and there were no significant differences between the two acquisitions of the patients. In addition, we found that the disease severity correlated negatively (P < .007) with integration, segregation, centrality, and small-worldness of the networks. Moreover, we found significantly (P < .0003) decreased local efficiency in the left supramarginal gyrus and temporal plane, and decreased strength in the right lingual gyrus.

CONCLUSIONS

We found significant global and local network alterations in juvenile neuronal ceroid lipofuscinosis that correlated with the disease severity and in areas related to the symptomatology.

Semantic language deficit developing following herpes simplex encephalitis: reorganization "cannibalising" language centers?

Herpes simplex virus encephalitis (HSVE) commonly presents with severe amnesia due to virus-mediated destruction of key regions in the temporal lobes, although language and executive impairment has been described. Little is known however of the long-term cognitive changes in these patients, including changes that may happen with cortical reorganization. We describe a patient with HSVE who presented with a highly unusual late-onset language syndrome, which may reflect distal cortical changes after her original injury.

Crossed aphasia in multiple sclerosis

Aphasia is a rare sign of multiple sclerosis (MS). Several different forms of aphasia have been reported in MS. We report, to our knowledge, the first case of a MS patient with crossed aphasia during an attack.

A cute verbal dyspraxia, a rare presentation in multiple sclerosis: a case report with MRI localization

C ortical speech disorders rarely occur in multiple sclerosis (MS). We report a patient with relapsing-remitting MS, who presented with acute verbal dyspraxia. Magnetic resonance imaging (MRI) demonstrated an acute T2/Flair hyperintense, primarily white matter lesion underlying the middle third of the inferior frontal gyrus. The verbal dyspraxia cleared beginning 48 hours after the initiation of iv dexamethasone. Follow-up MRI demonstrated qualitative and quantitative diminution of the hyperintensity. This is the first report of a clinically definite MS patient with acute verbal dyspraxia. Moreover, there was a suggestive localization of verbal praxis to Brodmann areas 44/45.

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.

Relatively normal repetition performance despite severe disruption of the left arcuate fasciculus

The arcuate fasciculus (AF) is believed to be fundamental to the neural circuitry behind many important cognitive processes. Connecting Wernicke's and Broca's area, these fibers are thought to be especially important for repetition. In this case study we present evidence from a patient that set doubt on these assumptions. We present structural imaging, diffusion tensor imaging, and language data on a patient with a large left-sided stroke and severely damaged left AF who showed intact word repetition and relatively intact sentence repetition performance. Specifically, his sentence repetition is more fluent and grammatical, with less hesitation than spontaneous speech, and with rare omissions only during the longest sentences. These results challenge classical theories that maintain the left AF is the dominant language processing pathway or mechanism for repetition.

Cognitive and neurobehavioral features in multiple sclerosis

Multiple sclerosis (MS) is the most common nontraumatic neurological condition of early and middle adulthood. Cognitive and neurobehavioral problems associated with this disorder are common. Approximately 50% of MS patients experience lifetime clinical depression, and at least 50% will experience significant cognitive difficulties. Fatigue is also extremely common and disabling in MS and appears to be associated with sleep problems and primary neurological features, in addition to secondary factors, including depression and pain. Quality of life is affected in MS by all of these factors and is an especially salient issue given that patients often live for many years following diagnosis. In this article, we explore the literature on cognitive and neurobehavioral features in MS, provide a commentary on the state of the literature and make suggestions for research directions over the next 5 years that would move the field forward significantly.

Cognitive functioning in multiple sclerosis

In this article, the nature and course of cognitive dysfunction in MS are reviewed, particularly in the context of recent advances in our understanding of the diffuse nature of neuropathology in MS, and in the context of specific factors that may confer risk or protection for the development of cognitive impairment. In addition, assessment and screening approaches of MS-related cognitive dysfunction are discussed. MS is a condition not only restricted to the adult population, and this article includes a brief description of cognition in pediatric-onset MS. Finally, promising intervention approaches to treat cognitive problems in MS are summarized.

Cognitive impairments in relapsing-remitting multiple sclerosis: a meta-analysis

There is debate in the literature regarding the magnitude, nature, and influence of cognitive impairment in individuals with relapsing-remitting multiple sclerosis (RRMS). Therefore, we conducted a meta-analysis that quantified the overall magnitude of cognitive impairment in individuals with RRMS and identified the domains of cognition and clinical/demographic variables that were moderators of the overall effect. We included 57 studies with 3891 participants that yielded a total of 755 effect sizes. Overall, there was a moderate decline in cognitive functioning in individuals with RRMS compared with healthy controls. Larger effects were observed in cognitive domains of motor functioning, mood status and memory and learning. Regarding demographic and clinical variables, age and gender were moderators of cognitive impairment in all cognitive domains, whereas neurological disability and disease duration primarily moderated performance on tasks assessing memory and learning.

Conduction aphasia as a function of the dominant posterior perisylvian cortex

✓ Assessment of eloquent functions during brain mapping usually relies on testing reading, speech, and comprehension to uncover transient deficits during electrical stimulation. These tests stem from findings predicted by the Geschwind–Wernicke hypothesis of receptive and expressive cortices connected by white matter tracts. Later work, however, has emphasized cortical mechanisms of language function. The authors report two cases that demonstrate that conduction aphasia is cortically mediated and can be inadequately assessed if not specifically evaluated during brain mapping.

To determine the distribution of language on the dominant cortex, electrical cortical stimulation was performed in two cases by using implanted subdural electrodes during brain mapping before epilepsy surgery. A transient isolated deficit in repetition of language was reported during stimulation of the posterior portion of the dominant superior temporal gyrus in one patient and during stimulation of the supramarginal gyrus in the other patient.

These cases demonstrate a localization of language repetition to the posterior perisylvian cortex. Brain mapping of this region should include assessment of verbal repetition to avoid potential deficits resembling conduction aphasia.

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.

Neurobehavioral aspects of cerebral white matter disorders

The study of higher function in humans requires a consideration of all the neural tissues in the brain. Long neglected as a contributor to the organization of cognitive and emotional operations, the cerebral white matter is now the subject of substantial effort to improve understanding. Among the many approaches that can address this area usefully, the study of individuals with white matter disorders offers a wealth of clinical insights that exploits the time-tested lesion method of behavioral neurology. This process is complemented by sophisticated neuroimaging techniques that increasingly enable detailed visualization of white matter tracts as they participate in the cognitive and emotional operations of distributed neural networks. In practical terms, an appreciation of the neurobehavioral importance of white matter disorders can be of great benefit for patients seen by neurologists and psychiatrists alike, especially because early recognition and treatment often can have an important influence on outcome. In theoretical terms, a focus on the white matter and its disorders promises to expand knowledge of the brain as an extraordinarily complex organ in which the connectivity provided by white matter is central to cognition, emotion, and consciousness itself. As the details of white matter structure and function become clarified, a more complete portrait of the organ of the mind can be anticipated.

Sudden onset aphasic hemiplegia: an unusual manifestation of disseminated encephalomyelitis

The association of the sudden onset of aphasia with hemiplegia, hemisenosry defect, and facial palsy, with MRI evidence of white matter lesions, requires differentiation between multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM). We have observed eight patients with such a syndrome, all of whom were originally diagnosed as multiple sclerosis, but who, on closer examination, turned out to be instances of disseminated encephalomyelitis. The patterns of demyelination seen in T2-weighted MRI are quite different in both conditions. In two of our patients, MRI reverted to normal after the treatment; in others, the images remained unchanged. A review of the reported cases of multiple sclerosis presenting with the acute onset of aphasia, reveals that the majority of them are, in reality, instances of acute disseminated encephalomyelitis with a much better prognosis. Most of these cases are monophasic and immunomodulatory treatment is inappropriate.

Mechanism of short-term memory and repetition in conduction aphasia and related cognitive disorders: a neuropsychological, audiological and neuroimaging study

To evaluate the role of the sub-cortical white matter and cortical areas of the supramarginal gyrus in short-term memory impairment (shortened digit or letter span) and repetition difficulty, four patients with conduction aphasia and impaired short-term memory and two patients with only short-term memory impairment were given digit span, letter span, speech audiometry and dichotic listening tests. The results showed that in most of the patients letter span was inferior to digit span and that bilateral ear suppression in the dichotic listening test was observed in two patients with a lesion in the inferior part of the supramarginal gyrus, suggesting that what was affected was phonological information and that the supramarginal gyrus was the storage site. The overlapped lesion of conduction aphasia patients with short-term memory impairment was the periventricular white matter at the upper to middle part of the trigone, while patients with only short-term memory impairment had a lesion in the inferior supramarginal gyrus in common. Thus, damage to the periventricular white matter at the trigone may yield the phonemic paraphasia characteristic of conduction aphasia, while damage to the inferior part of the supramarginal gyrus may result in the impairment of short-term memory. We believe that as a part of the mechanisms of short-term memory and repetition, phonological information is processed in the primary auditory cortex and goes through the periventricular white matter to the inferior part of the supramarginal gyrus and is temporarily stored there.