Assessing brain and cognitive function in multiple sclerosis cross-sectionally and longitudinally with multimodal methods : insights form high-density electrophysiology, neuropsychological examination and magnetic resonance imaging

THESIS 10333Cognitive impairment (CI) affects up to 65% of multiple sclerosis (MS) patients and can occur in the absence of physical disability (Hoffmann, Tittgemeyer, & von Cramon, 2007). MS is the most common chronic inflammatory demyelinating disease affecting the central nervous system among young adults in Western countries leading to severe disability, as there is no cure (Filippi, 2011). During early disease course, 85% of MS patients present with alternating periods of incapacitating relapses and stable remissions (relapsing-remitting MS, RRMS). This later develops into the secondary-progressive (SPMS) phase, characterised by less relapses but increasing disability. A minority (15%) of patients have a progressive accumulation of disability without relapses (primary-progressive, PPMS)(Rejdak, Jackson, & Giovannoni, 2010). CI in MS occurs most often for information processing speed, attention and working memory (Rogers & Panegyres, 2007). CI in MS is to some degree related to concurrent brain changes such as lesions (R.H. Benedict & Zivadinov, 2011). CI may significantly limit the independence and quality of life of MS patients (Amato, et al., 1995). Thus it is crucial to create innovative methods to support the early detection, efficient monitoring and treatment of the CI in MS

Impaired information processing speed and attention allocation in multiple sclerosis patients versus controls: A high-density EEG study

Background: The no-go P3a is a variant of the P300 event-related potential (ERP) that indexes speed of information processing and attention allocation. The aim of this study was to compare ERP findings with results from the paced auditory serial addition test (PASAT) and quantify latency, amplitude and topographical differences in P3a ERP components between multiple sclerosis (MS) patients and controls. Patients and Methods: Seventy-four subjects (20 relapsing remitting (RRMS) patients, 20 secondary progressive (SPMS) patients and 34 controls) completed a three-stimulus oddball paradigm (target, standard, nontarget). Subjects participated in separate visual and auditory tasks while data were recorded from 134 EEG channels. Latency differences were tested using an ANCOVA. Topographical differences were tested using statistical parametric mapping. Results: Visual P3a amplitude correlated with PASAT score in all MS patients over frontal and parietal areas. There were significant differences in latency, amplitude, and topography between MS patients and controls in the visual condition. RRMS and SPMS patients differed in visual P3a latency and amplitude at frontal and parietal scalp regions. In the auditory condition, there were latency differences between MS patients and controls only over the parietal region. Conclusion: The present results demonstrate that information processing speed and attention allocation are impaired in MS

Preliminary Evidence for Correlation Between PASAT Performance and P3a and P3b amplitudes in progressive multiple sclerosis.

Background. The no-go P3a event-related potential (ERP) is a measure of attentional engagement and the P3b is a measure of context updating. The aim of this study was to compare ERP topographies 1) to Paced Auditory Serial Addition Test (PASAT) results, 2) of visual and auditory P3a and P3b of PPMS patients vs. SPMS patients and 3) of both progressive subtypes to healthy controls. Methods. 30 subjects (10 PPMS, 10 SPMS and 10 age-matched controls) completed visual and auditory no-go P3a and P3b tasks while data were recorded from a 128-scalp channel EEG array. Data from scalp channels were converted into continuous interpolated images (incorporating the entire scalp and time). Topographical differences and correlations were then tested using statistical parametric mapping (SPM). Results. For the MS patients, PASAT score correlated significantly with parietal regions in the auditory P3b, auditory P3a and visual P3b conditions, and with central regions in the visual P3a condition. PPMS patients had significantly lower amplitude than SPMS patients in the auditory P3b condition over the parietal area. The control group had greater amplitude than the MS patients in all the P3 tasks, with the exception of the auditory P3b. Conclusions. These data suggest that PASAT performance and P3 ERPs correlate for MS progressive subtypes and that PPMS and SPMS in electrophysiologic responses differ during auditory P3b tasks

A high-density ERP study reveals latency, amplitude, and topographical differences in multiple sclerosis patients versus controls.

Objective. To quantify latency, amplitude and topographical differences in event-related potential (ERP) components between multiple sclerosis (MS) patients and controls and to compare ERP findings with results from the paced auditory serial addition test (PASAT). Methods. Fifty-four subjects (17 relapsing remitting (RRMS) patients, 16 secondary progressive (SPMS) patients, and 21 controls) completed visual and auditory oddball tasks while data were recorded from 134 EEG channels. Latency and amplitude differences, calculated using composite mean amplitude measures, were tested using an ANOVA. Topographical differences were tested using statistical parametric mapping (SPM). Results. In the visual modality, P2, P3 amplitudes and N2 latency were significantly different across groups. In the auditory modality, P2, N2, and P3 latencies and N1 amplitude were significantly different across groups. There were no significant differences between RRMS and SPMS patients on any ERP component. There were topographical differences between MS patients and controls for both early and late components for the visual modality, but only in the early components for the auditory modality. PASAT score correlated significantly with auditory P3 latency for MS patients. Conclusions. There were significant ERP differences between MS patients and controls. Significance. The present study indicated that both early sensory and later cognitive ERP components are impaired in MS patients relative to controls

Perceptual and Social Attributes Underlining Age-Related Preferences for Faces

Although aesthetic preferences are known to be important in person perception and can play a significant role in everyday social decisions, the effect of the age of the observer on aesthetic preferences for faces of different ages has not yet been fully investigated. In the present study we investigated whether aesthetic preferences change with ageing, with an age-related bias in favouring faces from one’s own age group. In addition, we examined the role of age on both the perceptual qualities and the social attributes of faces that may influence these aesthetic judgements. Both younger and older adult observers provided ratings to images of younger, middle-aged and older unfamiliar faces. As well as attractiveness, the rating dimensions included other perceptual (distinctiveness, familiarity) and social (competence, trustworthiness and dominance) factors. The results suggested a consistent aesthetic preference for youthful faces across all ages of the observers but, surprisingly, no evidence for an age-related bias in attractiveness ratings. Older adults tended to provide higher ratings of attractiveness, competence and trustworthiness to the unfamiliar faces, consistent with the positivity effect previously reported. We also tested whether perceptual factors such as face familiarity or distinctiveness affected aesthetic ratings. Only ratings of familiarity, but not distinctiveness, were positively associated with the attractiveness of the faces. Moreover, ratings of familiarity decreased with increasing age of the face. With regard to the social characteristics of the faces, we found that the age of the face negatively correlated with ratings of trustworthiness provided by all observers, but with the competence ratings of older observers only. Interestingly, older adults provided higher ratings of perceived competence and trustworthiness to younger than older faces. However, our results also suggest that higher attractiveness ratings, together with older aged faces, led to more positive evaluations of competence. The results are discussed within the context of an age-related decline in the differentiation of faces in memory. Our findings have important implications for a better understanding of age-related perceptual factors and cognitive determinants of social interactions with unfamiliar others across the adult lifespan

Neural bases of social deficits in ADHD: a systematic review. Does the Theory of Mind matter?

This study aims to systematically review the neural bases of Theory of Mind deficits in ADH

Study data

The study dat