Multiple sclerosis and behavior

Cognitive impairment in multiple sclerosis: from phenomenology to neurobiological mechanisms

Multiple sclerosis (MS) is an autoimmune-mediated disease of the central nervous system characterized by inflammation, demyelination and chronic progressive neurodegeneration. Among its broad and unpredictable range of clinical symptoms, cognitive impairment (CI) is a common and disabling feature greatly affecting the patients' quality of life. Its prevalence is 20% up to 88% with a wide variety depending on the phenotype of MS, with highest frequency and severity in primary progressive MS. Involving different cognitive domains, CI is often associated with depression and other neuropsychiatric symptoms, but usually not correlated with motor and other deficits, suggesting different pathophysiological mechanisms. While no specific neuropathological data for CI in MS are available, modern research has provided evidence that it arises from the disease-specific brain alterations. Multimodal neuroimaging, besides structural changes of cortical and deep subcortical gray and white matter, exhibited dysfunction of fronto-parietal, thalamo-hippocampal, default mode and cognition-related networks, disruption of inter-network connections and involvement of the γ-aminobutyric acid (GABA) system. This provided a conceptual framework to explain how aberrant pathophysiological processes, including oxidative stress, mitochondrial dysfunction, autoimmune reactions and disruption of essential signaling pathways predict/cause specific disorders of cognition. CI in MS is related to multi-regional patterns of cerebral disturbances, although its complex pathogenic mechanisms await further elucidation. This article, based on systematic analysis of PubMed, Google Scholar and Cochrane Library, reviews current epidemiological, clinical, neuroimaging and pathogenetic evidence that could aid early identification of CI in MS and inform about new therapeutic targets and strategies.

Alterations of Thalamic Nuclei Volumes and the Intrinsic Thalamic Structural Network in Patients with Multiple Sclerosis-Related Fatigue

Fatigue is a debilitating and prevalent symptom of multiple sclerosis (MS). The thalamus is atrophied at an earlier stage of MS and although the role of the thalamus in the pathophysiology of MS-related fatigue has been reported, there have been few studies on intra-thalamic changes. We investigated the alterations of thalamic nuclei volumes and the intrinsic thalamic network in people with MS presenting fatigue (F-MS). The network metrics comprised the clustering coefficient (Cp), characteristic path length (Lp), small-world index (σ), local efficiency (Eloc), global efficiency (Eglob), and nodal metrics. Volumetric analysis revealed that the right anteroventral, right central lateral, right lateral geniculate, right pulvinar anterior, left pulvinar medial, and left pulvinar inferior nuclei were atrophied only in the F-MS group. Furthermore, the F-MS group had significantly increased Lp compared to people with MS not presenting fatigue (NF-MS) (2.9674 vs. 2.4411, PAUC = 0.038). The F-MS group had significantly decreased nodal efficiency and betweenness centrality of the right mediodorsal medial magnocellular nucleus than the NF-MS group (false discovery rate corrected p < 0.05). The F-MS patients exhibited more atrophied thalamic nuclei, poorer network global functional integration, and disrupted right mediodorsal medial magnocellular nuclei interconnectivity with other nuclei. These findings might aid the elucidation of the underlying pathogenesis of MS-related fatigue.

Strain and sex differences in somatosensation and sociability during experimental autoimmune encephalomyelitis

Multiple Sclerosis (MS) is an immune-mediated disease that results in major locomotor deficits. However, recent studies have revealed that fatigue, slow processing speed, and memory impairment are the top variables impacting employment status for MS patients. These suggest that cognitive effects may have a greater impact on productivity, lifestyle, and quality of life than do disease-related motor deficits. However, these debilitating non-locomotive effects have been largely overlooked in rodent models of the disease, such as experimental autoimmune encephalomyelitis (EAE). We hypothesized that murine EAE can also be used to assess non-locomotive dysfunctions (mood, sociability, muscle strength, and balance), as well as potential biases in these dysfunctions due to sex and/or strain. We actively immunized male and female C57BL/6 (B6) and SJL mice for EAE and evaluated their performance on the Deacon's weight grip test, Kondziela's inverted screen test, Hall's rope grip test, manual von Frey test for somatic nociception, and a three-chamber social preference paradigm. We hypothesized that EAE progression is associated with changes in muscle strength, balance, pain, and sociability and that these variations are linked to sex and/or strain. Our results indicate that strain but not sex influenced differences in muscle strength and balance during EAE, and both sex and strain have an impact on mechanical nociception, regardless of EAE disease status. Furthermore, both sex and strain had complex effects on differences in sociability. In conclusion, testing these additional modalities during EAE helps to unveil other signs and symptoms that could be used to determine the efficacy of a drug or treatment in the modulation of a MS-like behavior.

Neuropsychiatric Symptoms of Multiple Sclerosis: State of the Art

Multiple Sclerosis (MS) is a chronic disabling neuroinflammatory disease. Psychiatric manifestations have a high prevalence in MS patients and may worsen the illness progression and the patients' quality of life (QoL). Depression is a highly prevalent condition in MS patients, associated with poorer adherence to treatment, decreased functional status and QoL, and increased suicide risk. Diagnosis and treatment of this disorder is challenging because of symptom overlap. Other prevalent psychiatric comorbidities are anxiety disorders, bipolar disorder, psychotic disorders, substance misuse and personality disorders. As the illness progresses, personality changes can happen, as well as affect abnormalities. Cognitive changes occur frequently in MS patients, and affect features like processing speed, attention, learning, memory, visual spatial capabilities, and some language deficits. Disease-modifying treatments may reduce cognitive impairment because of their container action on the brain's lesion burden. Other QoL determinants such as fatigue, pain, sexual dysfunction, exercise, resilience and social support should be taken into account, in order to promote the individuals' well-being. Further studies are needed in order to elucidate the effectiveness of pharmacotherapy and more neuroimaging studies are required to clarify the relationship between structural changes and psychiatric comorbidities.

Multiple Sclerosis and psychosis: A case report

Psychiatric symptoms resulting from Multiple Sclerosis (MS) itself or its treatment are well known. However, the relationship between psychotic episodes and Multiple Sclerosis remains debated. In this paper, we present the case of a woman who developed a chronic psychotic disorder a few months after the onset of MS. We describe the process which led us to make the diagnosis of Psychotic Disorder due to Medical Condition (Multiple Sclerosis). Because her criminal charges brought significant attention to her case, we also address the difficulty in treating a neurological condition with psychiatric features within the forensic context. Moreover, one of the main concerns of the patient was that Lyme Disease was the correct diagnosis as opposed to MS. We also report the difficulty of treating and initiating successful follow-up for a patient whose paranoia is enabled by the opinions of certain health advocacy groups.

Urgent and emergent psychiatric disorders

In the emergency department, neurologists regularly evaluate patients exhibiting behavioral abnormalities that stem from underlying neurologic diseases. This behavior may be the initial presence of a neurologic illness or may indicate the deterioration and progress of the disease process. In addition, many neurologic patients present with acute and potentially dangerous psychiatric symptoms that demand rapid and accurate management. Assessment, diagnosis, and treatment of patients with psychiatric manifestations in the context of neurologic illness pose a significant challenge to treating neurologists. This article discusses a general approach to assessment and treatment of some of the more common psychiatric disorders.

Personality characteristics and disorders in multiple sclerosis patients: assessment and treatment

Multiple sclerosis (MS) is a major inflammatory and demyelinating disease of the central nervous system. Although a significant incidence and prevalence of psychological disorders in MS has been reported there is limited data on the prevalence of personality disorders (PD) in these patients. Recent findings indicate the need for early diagnosis and treatment of PD in MS patients in the interests of prognosis, conformity to treatment and patient's quality of life improvement. This article summarizes existing evidence on prevalence, types and diagnostic criteria of PD in MS, clinical manifestations of personality pathology or changes in MS patients, and instruments currently used for diagnosis and assessment of PD in this group of patients. Underlying mechanisms suggested as causes of personality changes in MS patients are also discussed. The article reviews therapeutic strategies, including pharmacotherapy and psychotherapy interventions and emphasizes the need for a multidisciplinary approach to patient's treatment.

Cognitive decline in multiple sclerosis: impact of topographic lesion distribution on differential cognitive deficit patterns

Background: Multiple sclerosis (MS) is often accompanied by cognitive dysfunction. A negative correlation between cerebral lesion load and atrophy and cognitive performance has been pointed out almost consistently. Further, the distribution of lesions might be critical for the emergence of specific patterns of cognitive deficits.

Objective: The current study evaluated the significance of total lesion area (TLA) and central atrophy for the prediction of general cognitive dysfunction and tested for a correspondence between lesion topography and specific cognitive deficit patterns.

Methods: Thirty-seven patients with MS underwent neuropsychological assessment and magnetic resonance imaging. Lesion burden and central atrophy were quantified. Patients were classified into three groups by means of individual lesion topography (punctiform lesions/periventricular lesions/confluencing lesions in both periventricular and extra-periventricular regions).

Results: TLA was significantly related to 7 cognitive variables, whereas third ventricle width was significantly associated with 20 cognitive parameters. The three groups differed significantly in their performances on tasks concerning alertness, mental speed, and memory function.

Conclusion: Third ventricle width as a straight-forward measure of central atrophy proved to be of substantial predictive value for cognitive dysfunction, whereas total lesion load played only a minor role. Periventricular located lesions were significantly related to decreased psychomotor speed, whereas equally distributed cerebral lesion load did not. These findings support the idea that periventricular lesions have a determinant impact on cognition in patients with MS.

The relationship between subjective reports of fatigue and executive control in multiple sclerosis

Previous studies failed to show a relationship between fatigue and cognitive performance. We used a theory-based Delayed Item Recognition (DIR) paradigm to examine the hypothesis that subjective reports of fatigue and executive control processes were related in MS. Participants were 20 individuals diagnosed with definite diagnosis of MS with Relapsing-Remitting course and 20 controls case matched for age, sex, education and IQ. The DIR paradigm manipulated executive demands in three conditions: Alone, Partial Interference (PI), and Complete Interference (CI). Fatigue was assessed using the Fatigue Severity Scale (FSS).

RESULTS

ANOVA Repeated measures analyses showed that DIR performance was slower and less accurate as a function of MS and increased executive demands across the three task conditions. Separate linear regressions revealed that fatigue was related to DIR reaction time and accuracy performance only in the CI condition where executive demands are maximized, and only in the MS group. The present study provided first behavioral evidence that fatigue and executive control are uniquely related in MS.

Psychopathology in multiple sclerosis: diagnosis, prevalence and treatment

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system. Demyelinization of nerve fibres not only affects the motor and sensory systems functionally, but may also cause psychopathological signs and symptoms. In addition to the psychiatric manifestations of MS, many patients have reactive psychological problems that are often hard to distinguish from the 'organic' causation of psychopathology. In any event, psychiatric comorbidity in MS deserves greater clinical attention than has been previously paid, because the presence of psychopathology may have deleterious effects on the disease process and impair coping with disability.

Evaluating sub-clinical cognitive dysfunction and event-related potentials (P300) in clinically isolated syndrome

OBJECTIVE

This study investigated the presence of sub-clinical cognitive dysfunction in patients with clinically isolated syndrome (CIS) and the abnormalities of cognitive event-related potentials (ERPs).

METHODS

Subclinical cognitive dysfunction was assessed in 20 patients with CIS and in 20 healthy controls.

RESULTS

Patients had impairments in verbal learning and long-term memory, evaluating attention, executive function and visuospatial skills, in decreasing order of frequency. SDLT and SIT were the most, and COWAT and BNT were the least affected tests. The N200 and P200 latencies were prolonged, and N100, N200 and P200 amplitudes were reduced in the patients relative to the controls, from the Fz, Cz and Pz electrode positions (p<0.05).

CONCLUSION

Detailed cognitive testing is valuable in determining subclinical cognitive dysfunction in CIS patients. ERP abnormalities as well as abnormalities in detailed cognitivetesting in patients with CIS are helpful in the diagnosis of sub-clinical cognitive dysfunction.

Family caregiver quality of life in multiple sclerosis among Kuwaitis: a controlled study

Background

Research interest in the quality of life (QOL) of persons with multiple sclerosis (MS) has been spurred by the need to broaden outcome measures. Far less of this interest has been directed at the family caregivers, who bear most of the burden of care. The objectives of the study were: First, to compare the subjective QOL of family caregivers of persons with relapsing remitting and progressive MS, with those of a matched general population sample and caregivers of diabetes and psychiatric patients. Second, to assess the relationship of QOL with caregiver attitudes to MS and patient's variables.

Methods

Consecutive MS clinic attendees were assessed with the 26 – item WHOQOL Instrument, and for depression and disability. Similarly, caregivers independently rated their own QOL as well as their impression of patients' QOL and attitudes to patients' illness.

Results

The 170 caregivers, mean age 35.7 years, had no significant diagnostic differences in QOL domain scores and attitudes to MS. Caregivers had significantly lower QOL than the general population control group for five out of six domains and the general facet (P < 0.01), but higher QOL than the patients. When the scores were corrected for patients' depression and disability, caregivers had similar QOL with the general population group for four domains. Using corrected scores, MS caregivers had lower scores than diabetic and psychiatric caregivers in the physical, psychological and social relations domains. Majority expressed negative attitudes to MS. Caregiver QOL was more affected by their fear of having MS than their feelings about the illness and caregiving role. Caregiver attitudes had mostly no significant impact on their proxy ratings of patients' QOL. The significant predictor of caregivers' overall QOL was their impression of patients' QOL.

Conclusion

Caregivers need specific attention if they are less educated, unemployed, afraid of having MS and caring for patients with longer duration of illness and less education. In particular, attention to patients' depression and disability could improve caregivers' QOL. Caregivers need specific programs to address fear of having MS, negative attitudes to illness and their unmet needs.

Pathological laughing as a manifestation in a clinically isolated brainstem syndrome: a case report

The prevalence of pathological laughing and crying in multiple sclerosis (MS) is 10%. It has been speculated that the anatomical lesion responsible for the pathological laughing is located in the pontine base, prefrontal cortex, and cerebellum. We report an 18-year-old male patient presenting with pathological laughing and hypomania. In his neurological examination, he had a euphoric effect with ataxic walking and dysarthria speech. He had a bilateral conjugated gaze limitation, with a prominent bilateral horizontal nystagmus on left gaze, dysmetria, dysdiadokokinesia, and remarkable dysfunction in a heel-to-shin test on the left. The IgG index in cerebrospinal fluid was normal with an oligoclonal band was present. In cranial MRI, there was a lesion on central pons which was hypointense in T1 images with contrast enhancement and hyperintense in T2 and flair images. Also another lesion in right brachium pontis which did not contrast enhancement but was hyperintense on T2 and flair images was present. There was an elevation of myoinositol/creatine ratio and choline and a reduction of NAA in proton MR spectroscopy. MR spectroscopic evaluation of the patient demonstrated the demyelination process. There has been no report of patients in whom pathological laughter was the presenting symptom of clinically isolated brainstem syndrome.