Psychiatric disturbances in radiologically isolated syndrome

Disease-modifying therapies for Parkinson disease: lessons from multiple sclerosis

The development of disease-modifying therapies (DMTs) for neurological disorders is an important goal in modern neurology, and the associated challenges are similar in many chronic neurological conditions. Major advances have been made in the multiple sclerosis (MS) field, with a range of DMTs being approved for relapsing MS and the introduction of the first DMTs for progressive MS. By contrast, people with Parkinson disease (PD) still lack such treatment options, relying instead on decades-old therapeutic approaches that provide only symptomatic relief. To address this unmet need, an in-person symposium was held in Toronto, Canada, in November 2022 for international researchers and experts in MS and PD to discuss strategies for advancing DMT development. In this Roadmap article, we highlight discussions from the symposium, which focused on therapeutic targets and preclinical models, disease spectra and subclassifications, and clinical trial design and outcome measures. From these discussions, we propose areas for novel or deeper exploration in PD using lessons learned from therapeutic development in MS. In addition, we identify challenges common to the PD and MS fields that need to be addressed to further advance the discovery and development of effective DMTs.

Alexithymia in radiologically isolated syndrome

BACKGROUND

Alexithymia refers to difficulty identifying (DIF) and describing (DDF) feelings and externally oriented thinking (EOT). Its prevalence remains unknown in the radiologically isolated syndrome (RIS), the preclinical multiple sclerosis (MS) phase.

METHODS

Alexithymia was measured with the Toronto Alexithymia Scale (TAS-20) in 29 RIS and age and gender-matched healthy controls and relapsing-remitting (RR) MS with an EDSS <3. All participants completed evaluations of cognition (BCCOG-SEP), depression (Fast-BDI), fatigue (EMIF), and quality of life (SEP-59).

RESULTS

The level of alexithymia was significantly different between the three groups, with the higher score in the RRMS group (mean score of 54.5, SD: 12,3) compared to RIS (mean score of 47.2, SD: 14.8) and in healthy controls (mean score of 41.9, SD:12.8). 34 % of RIS participants showed a pathological level of alexithymia. The proportions were 21.7 % in the healthy controls and 51.7 % in the RRMS-matched groups. The difference was mainly significant for the DIF factor, p<.001. No significant correlations were observed between alexithymia and the different measures of cognition. In the RIS group, alexithymia was strongly linked to the levels of depression and cognitive fatigue. Furthermore, alexithymia was related to decreased mental quality of life.

CONCLUSION

The study revealed that one-third of subjects with radiologically isolated syndrome show signs of alexithymia. Interestingly, no cognitive measure was found to be correlated with the level of alexithymia, which is consistent with previous research findings. Alexithymia and mainly difficulty identifying feelings in RIS are associated with depression but also relate to cognitive fatigue and reduced mental quality of life. This could impact the daily interactions of RIS subjects.

Evaluation of mental performance and cognitive functions of children and adolescents diagnosed with radiologically isolated syndrome

BACKGROUND

Radiologically isolated syndrome (RIS) is a condition characterized by asymptomatic, incidentally detected demyelinating plaques in the CNS in a patient without typical clinical findings of multiple sclerosis (MS). This study aimed to compare the mental status and cognitive functions of child and adolescent RIS cases with healthy controls and to investigate the relationship between psychometric test results and the demyelinating lesion characteristics.

METHODS

The mental status and cognitive functions of 12 RIS cases and 12 healthy controls were compared. Semi-structured interviews, behavioral evaluations, depression and anxiety scales, neuropsychological test battery, and an intelligence test were applied for the evaluation of mental state and cognitive functions. These results were compared with the number and localization of demyelinating lesions.

RESULTS

Sustained attention, visual-motor coordination, short-term memory skills, and ability to use visual-spatial information were found worse in the RIS group. There was no correlation between mental state and cognitive functions, and the number and localization of demyelinating lesions.

CONCLUSION

Our study showed that pediatric RIS cases may have worse cognitive performance than healthy controls, but no correlation was found between the number and location of demyelinating lesions and psychiatric findings. Although it is controversial whether psychiatric disorders and cognitive disabilities have predictive value in terms of MS conversion in pediatric RIS cases, these subjects were not included in the scope of this study.

Abnormal functional connectivity in radiologically isolated syndrome: A resting-state fMRI study

BACKGROUND

Radiologically isolated syndrome (RIS) patients might have psychiatric and cognitive deficits, which suggests an involvement of major resting-state functional networks. Notwithstanding, very little is known about the neural networks involved in RIS.

OBJECTIVE

To examine functional connectivity differences between RIS and healthy controls using resting-state functional magnetic resonance imaging (fMRI).

METHODS

Resting-state fMRI data in 25 RIS patients and 28 healthy controls were analyzed using an independent component analysis; in addition, seed-based correlation analysis was used to obtain more information about specific differences in the functional connectivity of resting-state networks. Participants also underwent neuropsychological testing.

RESULTS

RIS patients did not differ from the healthy controls regarding age, sex, and years of education. However, in memory (verbal and visuospatial) and executive functions, RIS patients' cognitive performance was significantly worse than the healthy controls. In addition, fluid intelligence was also affected. Twelve out of 25 (48%) RIS patients failed at least one cognitive test, and six (24.0%) had cognitive impairment. Compared to healthy controls, RIS patients showed higher functional connectivity between the default mode network and the right middle and superior frontal gyri and between the central executive network and the right thalamus (pFDR < 0.05; corrected). In addition, the seed-based correlation analysis revealed that RIS patients presented higher functional connectivity between the posterior cingulate cortex, an important hub in neural networks, and the right precuneus.

CONCLUSION

RIS patients had abnormal brain connectivity in major resting-state neural networks and worse performance in neurocognitive tests. This entity should be considered not an "incidental finding" but an exclusively non-motor (neurocognitive) variant of multiple sclerosis.

Third wave cognitive behavioural therapies for people with multiple sclerosis: a scoping review

PURPOSE

Multiple sclerosis (MS) is a chronic condition linked to a wide range of psychological difficulties. While traditional cognitive behavioural therapy has been studied extensively with people with MS, much less is known about more recent "third wave" approaches.

METHODS

A scoping review was carried out by performing a systematic search across MEDLINE Complete, PsycINFO, CINAHL, Academic Search Ultimate, and Cochrane Library up to January 2022.

RESULTS

From an initial return of 8306 citations, 35 studies were included, 20 of which were randomised controlled trials (RCTs). These showed that four third wave approaches have been investigated with people with MS to date: acceptance and commitment therapy (ACT), dialectical behaviour therapy (DBT), mindfulness-based stress reduction (MBSR), and mindfulness-based cognitive therapy (MBCT). MBSR and MBCT may be helpful to address a range of psychological difficulties up to three months post-intervention. However, MS-specific adaptations may be required, and more evidence is needed on longer-term effectiveness. Limited evidence is also available for DBT and ACT, but additional research is warranted before any recommendation can be made.

CONCLUSIONS

As third wave approaches keep being refined, further more rigorous investigations are needed to implement them to the benefit of people with MS. Implications for RehabilitationMultiple sclerosis is linked to a wide range of psychological difficulties in adults.Little is currently known on third wave psychotherapies for people with MS.Mindfulness-based stress reduction and mindfulness-based cognitive therapy may be helpful to address a wide range of difficulties in MS.Specific adaptations may be needed to deliver suitable therapies to people with MS.Additional research is warranted to build on preliminary findings for DBT and ACT.

Early multiple sclerosis: diagnostic challenges in clinically and radiologically isolated syndrome patients

PURPOSE OF REVIEW

With the introduction of new diagnostic criteria, the sensibility for multiple sclerosis (MS) diagnosis increased and the number of cases with the clinically isolated syndrome (CIS) decreased. Nevertheless, a misdiagnosis might always be around the corner, and the exclusion of a 'better explanation' is mandatory.There is a pressing need to provide an update on the main prognostic factors that increase the risk of conversion from CIS or from radiologically isolated syndrome (RIS) to MS, and on the potential 'red flags' to consider during the diagnostic workup.

RECENT FINDINGS

We discuss diagnostic challenges when facing patients presenting with a first demyelinating attack or with a RIS, with a focus on recently revised diagnostic criteria, on other neuroinflammatory conditions to be considered in the differential diagnosis and on factors distinguishing patients at risk of developing MS.A correct definition of a 'typical' demyelinating attack, as well as a correct interpretation of MRI findings, remains crucial in the diagnostic process. The cerebrospinal fluid examination is warmly recommended to confirm the dissemination in time of the demyelinating process and to increase the diagnostic accuracy.

SUMMARY

An early and accurate diagnosis of MS requires careful consideration of all clinical, paraclinical and radiological data, as well the reliable exclusion of other mimicking pathological conditions. This is advocated to promptly initiate an appropriate disease-modifying therapy, which can impact positively on the long-term outcome of the disease.

Using advanced analysis of multifocal visual-evoked potentials to evaluate the risk of clinical progression in patients with radiologically isolated syndrome

This study aimed to assess the role of multifocal visual-evoked potentials (mfVEPs) as a guiding factor for clinical conversion of radiologically isolated syndrome (RIS). We longitudinally followed a cohort of 15 patients diagnosed with RIS. All subjects underwent thorough ophthalmological, neurological and imaging examinations. The mfVEP signals were analysed to obtain features in the time domain (SNR_min: amplitude, Lat_max: monocular latency) and in the continuous wavelet transform (CWT) domain (b_max: instant in which the CWT function maximum appears, N_max: number of CWT function maximums). The best features were used as inputs to a RUSBoost boosting-based sampling algorithm to improve the mfVEP diagnostic performance. Five of the 15 patients developed an objective clinical symptom consistent with an inflammatory demyelinating central nervous system syndrome during follow-up (mean time: 13.40 months). The (SNR_min) variable decreased significantly in the group that converted (2.74 ± 0.92 vs. 4.07 ± 0.95, p = 0.01). Similarly, the (b_max) feature increased significantly in RIS patients who converted (169.44 ± 24.81 vs. 139.03 ± 11.95 (ms), p = 0.02). The area under the curve analysis produced SNR_min and b_max values of 0.92 and 0.88, respectively. These results provide a set of new mfVEP features that can be potentially useful for predicting prognosis in RIS patients.

[Radiologically isolated syndrome: prognosis and predictors of conversion to multiple sclerosis]

Increased sensitivity and availability of magnetic resonance imaging (MRI) in neurological routine practice led to the fact that more and more experts began to encounter changes typical for multiple sclerosis (MS) according to MRI in the absence of anamnestic and clinical indications of damage to the central nervous system (CNS). This nosological form has been defined as a radiologically isolated syndrome (RIS). More and more RIS cases convert to MS (up to 30% in the first 5 years after RIS diagnosis). At the moment, there are no biological markers that allow combining RIS and MS into one pathological process and early treatment with disease-modifying drugs (DMT). Prospective studies are actively being conducted to identify demographic, clinical, neuroimaging and biochemical conversion predictors. The identification of the molecular biological RIS features, combining these changes with MS, is an urgent scientific task and will allow timely initiation of therapy of the pathological process already at the subclinical stage.

[Norepinephrine and intestinal microbiome in the early stages of demyelination: clinical-immunological parallels]

Biogenic amines are key mediators of neuroimmune interaction and may influence on multiple sclerosis (MS) pathogenesis and MS course. At the same time, the role of biogenic amines in immunoregulation of early stages of demyelination, in particular clinically isolated syndrome (CIS) and radiologically isolated syndrome (RIS) is still unclear. This literature review addresses a role of norepinephrine in the regulation of neuroimmune interactions in the early stages of the demyelination. Neuropsychological disorders, immunological characteristics, gut-brain axis as well as the role of norepinephrine in these interactions in patients with CIS, RIS and early MS are discussed.

Classification of radiologically isolated syndrome and clinically isolated syndrome with machine-learning techniques

BACKGROUND AND PURPOSE

The unanticipated detection by magnetic resonance imaging (MRI) in the brain of asymptomatic subjects of white matter lesions suggestive of multiple sclerosis (MS) has been named radiologically isolated syndrome (RIS). As the difference between early MS [i.e. clinically isolated syndrome (CIS)] and RIS is the occurrence of a clinical event, it is logical to improve detection of the subclinical form without interfering with MRI as there are radiological diagnostic criteria for that. Our objective was to use machine-learning classification methods to identify morphometric measures that help to discriminate patients with RIS from those with CIS.

METHODS

We used a multimodal 3-T MRI approach by combining MRI biomarkers (cortical thickness, cortical and subcortical grey matter volume, and white matter integrity) of a cohort of 17 patients with RIS and 17 patients with CIS for single-subject level classification.

RESULTS

The best proposed models to predict the diagnosis of CIS and RIS were based on the Naive Bayes, Bagging and Multilayer Perceptron classifiers using only three features: the left rostral middle frontal gyrus volume and the fractional anisotropy values in the right amygdala and right lingual gyrus. The Naive Bayes obtained the highest accuracy [overall classification, 0.765; area under the receiver operating characteristic (AUROC), 0.782].

CONCLUSIONS

A machine-learning approach applied to multimodal MRI data may differentiate between the earliest clinical expressions of MS (CIS and RIS) with an accuracy of 78%.

Anomalies Characteristic of Central Nervous System Demyelination: Radiologically Isolated Syndrome

Radiologically isolated syndrome (RIS) was defined in 2009 for asymptomatic patients who presented incidentally identified white matter anomalies within the central nervous system suggestive of multiple sclerosis (MS). Approximately one-third of RIS subjects will have a seminal clinical demyelinating event within 5 years of the identification of their abnormal MRI. Clinical evolution mirrors relapsing remitting or progressive forms of MS. Pejorative factors for clinical conversion are male gender, age younger than 35 years, and spinal cord lesions.

Radiologically isolated syndrome in children: Current knowledge and future directions

As the use of magnetic resonance imaging (MRI) grows in clinical practice, clinicians are increasingly faced with the difficult task of interpreting the significance of incidental findings on brain MRI. Among individuals found to have incidental brain MRI findings, a small number have white matter abnormalities on MRI that resemble the demyelinating lesions of multiple sclerosis (MS) in the absence of a history of relevant clinical symptoms. This has been termed radiologically isolated syndrome (RIS). Recent years have seen growing interest in RIS, with observational studies that have specifically focused on answering questions regarding the subsequent risk of future clinical events and diagnosis of MS in adults and children with these findings. Given the high rate of subsequent clinical events seen in adult studies, knowledge related to RIS in children is paramount, particularly given the higher disease activity and burden in children with MS. This review examines this question, providing an overview of RIS with a focus on its significance in children including current definitions, its association with MS, and knowledge related to therapeutic interventions for RIS. We conclude with suggestions for an approach to assessment of and subsequent surveillance in children fulfilling criteria for RIS and directions for future study.

Symptom Management and Lifestyle Modifications in Multiple Sclerosis

PURPOSE OF REVIEW

This article reviews the rationale and approach to symptom management and lifestyle modifications in multiple sclerosis (MS).

RECENT FINDINGS

MS symptoms are important to treat because they affect quality of life and daily activity. Appreciation of cluster symptoms (where one symptom contributes to another), changes over time, and multimodality therapeutic approaches are guiding optimized symptom management. Equally important are lifestyle modifications that enhance central nervous system reserve and function. These modifications are the foundation for a health maintenance, wellness, and vascular risk factor control program.

SUMMARY

Symptom management and lifestyle modifications are important therapeutic targets to improve the lives of patients with MS.

Preclinical disease activity in multiple sclerosis: A prospective study of cognitive performance prior to first symptom

OBJECTIVE

To prospectively investigate potential signs of preclinical multiple sclerosis (MS) activity and when they are present prior to first symptom using data from a historical cohort.

METHODS

We linked the cognitive performance of all Norwegian men born 1950-1995 who underwent conscription examination at age 18 to 19 years to the Norwegian MS registry to identify those later developing MS, and randomly selected controls frequency-matched on year of birth from the Norwegian Conscript Service database. In this nested case-control study, cognitive test scores were available for 924 male cases and 19,530 male controls. We estimated mean score differences among cases and controls (Student t test) and the risk of developing MS comparing lower to higher scores (Cox regression) in strata of years to clinical onset.

RESULTS

Men developing first clinical MS symptoms up to 2 years after the examination scored significantly lower than controls (Δ = 0.80, p = 0.0095), corresponding to a 6 intelligence quotient (IQ)-point difference. Those scoring lowest, that is, >1 standard deviation below the controls' mean, had an increased MS risk during the 2 following years (relative risk = 2.81, 95% confidence interval = 1.52-5.20). Whereas results were similar for relapsing-remitting MS cases (RRMS), those developing primary-progressive MS (PPMS) scored a significant 4.6 to 6.9 IQ points lower than controls up to 20 years prior to first progressive symptoms.

INTERPRETATION

RRMS may start years prior to clinical presentation, and disease processes in PPMS could start decades prior to first apparent progressive symptoms. Cognitive problems could be present in both MS forms before apparent symptoms. Apart from potential implications for clinical practice and research, these findings challenge our thinking about the disease. Ann Neurol 2016;80:616-624.

Body size and physical exercise, and the risk of multiple sclerosis

BACKGROUND

Whether large body size increases multiple sclerosis (MS) risk in men is not well understood. Concurrently, physical exercise could be an independent protective factor.

OBJECTIVE

To prospectively investigate the association between body mass index (BMI) and aerobic fitness, indicators of body size and exercise, and MS risk in men.

METHODS

We performed a population-based nested case-control study within the historical cohort of all Norwegian men, born in 1950-1975, undergoing mandatory conscription at the age of 19 years. 1016 cases were identified through linkage to the Norwegian MS registry, while 19,230 controls were randomly selected from the cohort. We estimated the effect of BMI and fitness at conscription on MS risk using Cox regression.

RESULTS

Higher BMI (≥25 vs 18.5-<25 kg/m²) was significantly associated with increased MS risk (adjusted relative risk (RR_adj) = 1.36, 95% confidence interval (CI): 1.05-1.76). We also found a significant inverse association between aerobic fitness (high vs low) and MS risk independent of BMI (RR_adj = 0.69, 95% CI: 0.55-0.88, p-trend = 0.003), remaining similar when men with MS onset within 10 years from conscription were excluded ( p-trend = 0.03).

CONCLUSION

These findings add weight to evidence linking being overweight to an increased MS risk in men. Furthermore, they suggest that exercise may be an additional modifiable protective factor for MS.

Radiologically isolated syndrome: An update on a rare entity

Our understanding of radiologically isolated syndrome (RIS) is evolving, as new data emerge on the clinical characterization and the pathophysiological nature of this rare entity. This topical review aims to (1) outline state-of-the-art clinical and magnetic resonance imaging findings of RIS research; (2) raise the main obstacles to RIS research; (3) discuss the most controversial issues of current RIS findings; and (4) highlight potential strategies for upcoming research studies.

Normal-appearing brain tissue analysis in radiologically isolated syndrome using 3 T MRI

To date, it remains largely unknown whether there is in radiologically isolated syndrome (RIS) brain damage beyond visible T2 white matter lesions. We used single- voxel proton magnetic resonance spectroscopy and diffusion tensor imaging (3 T MRI) to analyze normal-appearing brain tissue regions in 18 RIS patients and 18 matched healthy controls. T2-hyperintense lesion volumes and structural brain volumes were also measured. The absolute metabolite concentrations and ratios of total N-acetylaspartate+N-acetylaspartyl glutamate (NAA), choline-containing compounds, myoinositol, and glutamine-glutamate complex to creatine were calculated. Spectral analysis was performed by LCModel. Voxelwise morphometry analysis was performed to localize regions of brain tissue showing significant changes of fractional anisotropy or mean diffusivity. Compared with healthy controls, RIS patients did not show any significant differences in either the absolute concentration of NAA or NAA/Cr ratio in mid-parietal gray matter. A trend toward lower NAA concentrations (-3.35%) was observed among RIS patients with high risk for conversion to multiple sclerosis. No differences in the other metabolites or their ratios were observed. RIS patients showed lower fractional anisotropy only in clusters overlapping lesional areas, namely in the cingulate gyrus bilaterally and the frontal lobe subgyral bilaterally (P < 0.001). Normalized brain and cortical volumes were significantly lower in RIS patients than in controls (P = 0.01 and P = 0.03, respectively). Our results suggest that in RIS, global brain and cortical atrophy are not primarily driven by significant occult microstructural normal appearing brain damage. Longitudinal MRI studies are needed to better understand the pathological processes underlying this novel entity.

Gray Matter Involvement in Radiologically Isolated Syndrome

The unanticipated magnetic resonance imaging (MRI) detection in the brain of asymptomatic subjects of white matter lesions suggestive of multiple sclerosis has recently been named as radiologically isolated syndrome (RIS). The pathophysiological processes of RIS remain largely unknown and questions as to whether gray matter alterations actually occur in this entity are yet to be investigated in more detail. By means of a 3 T multimodal MRI approach, we searched for cortical and deep gray matter changes in a cohort of RIS patients. Seventeen RIS patients, 17 clinically isolated syndrome (CIS) patients (median disease duration from symptom onset = 12 months), and 17 healthy controls underwent MRI and neuropsychological testing. Normalized deep gray matter volumes and regional cortical thickness were assessed using FreeSurfer. SIENAX was used to obtain normalized global and cortical brain volumes. Voxelwise morphometry analysis was performed by using SPM8 software to localize regions of brain tissue showing significant changes of fractional anisotropy or mean diffusivity. Although no differences were observed between CIS and healthy controls groups, RIS patients showed significantly lower normalized cortical volume (673 ± 27.07 vs 641 ± 35.88 [cm³ × 10³, Tukey P test = 0.009) and mean thalamic volume (0.0051 ± 0.4 vs 0.0046 ± 0.4 mm, P = 0.014) compared with healthy controls. RIS patients also showed significant thinning in a number of cortical areas, that were primarily distributed in frontal and temporal lobes (P < 0.05, uncorrected). Strong correlations were observed between T2-white matter lesion volume and regional cortical thickness (rho spearman ranging from 0.60 to 0.80). Our data suggest that white matter lesions on T2-weighted images are not the only hallmark of RIS. Future longitudinal studies with larger samples are warranted to better clarify the effect of RIS-related white matter lesions on gray matter tissue.