Processing Speed In Multiple Sclerosis Research Articles

Machine Learning EEG to Predict Cognitive Functioning and Processing Speed Over a 2-Year Period in Multiple Sclerosis Patients and Controls.

Event-related potentials (ERPs) show promise to be objective indicators of cognitive functioning. The aim of the study was to examine if ERPs recorded during an oddball task would predict cognitive functioning and information processing speed in Multiple Sclerosis (MS) patients and controls at the individual level. Seventy-eight participants (35 MS patients, 43 healthy age-matched controls) completed visual and auditory 2- and 3-stimulus oddball tasks with 128-channel EEG, and a neuropsychological battery, at baseline (month 0) and at Months 13 and 26. ERPs from 0 to 700ms and across the whole scalp were transformed into 1728 individual spatio-temporal datapoints per participant. A machine learning method that included penalized linear regression used the entire spatio-temporal ERP to predict composite scores of both cognitive functioning and processing speed at baseline (month 0), and months 13 and 26. The results showed ERPs during the visual oddball tasks could predict cognitive functioning and information processing speed at baseline and a year later in a sample of MS patients and healthy controls. In contrast, ERPs during auditory tasks were not predictive of cognitive performance. These objective neurophysiological indicators of cognitive functioning and processing speed, and machine learning methods that can interrogate high-dimensional data, show promise in outcome prediction.

Improved processing speed in multiple sclerosis during fingolimod therapy: oral Symbol Digit Modalities Test response in PREFERMS (P4.331)

Improved processing speed in multiple sclerosis during fingolimod therapy: oral Symbol Digit Modalities Test response in PREFERMS (P4.331)

Unique Within-Network Functional Connections Characterize Memory and Information Processing Speed in Multiple Sclerosis (P4.346)

Unique Within-Network Functional Connections Characterize Memory and Information Processing Speed in Multiple Sclerosis (P4.346)

Information processing speed in multiple sclerosis: Past, present, and future

Background: Information processing speed (IPS) is a prevalent cognitive impairment in multiple sclerosis (MS). Objectives: This review aims to summarize the methods applied to assess IPS in MS and its theoretical conceptualization. A PubMed search was performed to select articles published between 1 January 2004 and 31 December 2013, resulting in 157 articles included. Results: The majority (54%) of studies assessed IPS with heterogeneous samples (several disease courses). Studies often report controlling for presence of other neurological disorders (60.5%), age (58.6%), education (51.6%), alcohol history (47.8%), or use of steroids (39.5%). Potential confounding variables, such as recent relapses (50.3%), history of developmental disorders (19.1%), and visual problems (29.9%), were often neglected. Assessments used to study IPS were heterogeneous (ranging from simple to complex tasks) among the studies under review, with 62 different tasks used. Only 9.6% of articles defined the construct of IPS and 22.3% discussed IPS in relation to a theoretical model. Future directions: The challenges for the upcoming decade include clarification of the definition of IPS as well as its theoretical conceptualization and a consensus on assessment. Based on the results obtained, we propose a new theoretical model, the tri-factor model of IPS.

Neuro-Ophthalmic Syndromes and Processing Speed in Multiple Sclerosis.

The impact of prior neuro-ophthalmic syndromes on the performance on vision-based neuropsychological tasks in patients with multiple sclerosis (MS) is unknown. Two groups of MS participants, one with (Msos+) and the other without (Msos-), a history of neuro-ophthalmic syndromes, underwent neuropsychological assessment and were compared with healthy age- and education-matched controls (HC). Participants with Msos+ performed significantly worse on the symbol digit modalities test than the Msos- (P < 0.03) and the HC groups (P < 0.01) and coding (P < 0.01). A clinical history of neuro-ophthalmic syndromes is associated with reduced performance on visual processing speed tasks.

Effects of single dose mixed amphetamine salts--extended release on processing speed in multiple sclerosis: a double blind placebo controlled study.

Multiple sclerosis (MS) commonly affects cognitive function, most frequently presenting as impaired processing speed (PS). There are currently no approved treatments for PS in this population, but previous studies suggest amphetamines may be beneficial. The objective of this study is to determine if mixed amphetamine salts, extended release (MAS-XR) has the potential to improve impaired PS in MS patients in a randomized controlled pre- and post-dose testing study. Fifty-two MS patients demonstrating PS impairment on either the Symbol Digit Modalities Test (SDMT) or Paced Auditory Serial Addition Test (PASAT) were randomized to a single dose of 5 mg MAS-XR (n = 18), 10 mg MAS-XR (n = 20), or placebo (n = 14). Subjects were evaluated a second time, after taking the blinded medication. ANOVA was used to compare the change on the SDMT and PASAT in each of the treatment groups compared to the placebo. Cohen's d was used to calculate effect size. At baseline, the mean SDMT score was 43.3 ± 7.2 and the mean PASAT was 34.8 ± 13.4, with 47 (90.4 %) and 25 (48.1 %) categorized as impaired on the SDMT and PASAT, respectively. The change in SDMT scores from baseline to post-treatment demonstrated significant improvement for the MAS-XR 10-mg dose compared to placebo, increasing by 5.2 ± 4.5 vs. 0.6 ± 4.4 points (p = 0.043), with a medium effect size of 0.47. Change on the PASAT was not significantly different in either treatment group. This study supports MAS-XR 10 mg as a potential treatment for MS patients with demonstrated PS impairment, warranting a larger longitudinal study.

Cannabis-induced alterations in brain activation during a test of information processing speed in patients with MS.

ObjectiveThe objective of this article is to determine the functional brain correlates of information processing speed in multiple sclerosis (MS) patients who smoke cannabis and those who are drug naïve.MethodsTwo neurologically and demographically matched samples of MS patients were enrolled, those who smoked cannabis daily (n = 20) and those who were cannabis naïve (n = 19). All participants completed the Brief Repeatable Battery of Neuropsychological Tests and underwent fMRI testing during which they were administered a modified version of the Symbol Digit Modalities Test (mSDMT).ResultsThe cannabis group responded slower in nine of 11 blocks of the mSDMT (p < 0.001), showing a trend toward a slower response time (p < 0.08), but did not differ in the accuracy of response (p < 0.18). Both groups displayed activation in a prefrontal cortex-parietal network associated with information processing speed. When compared to the cannabis-naïve group, cannabis users showed less activation in the right (p = 0.009) and left (p = 0.001) thalami and increased activation in the anterior cingulate (p = 0.006).ConclusionRegular cannabis use in MS patients is associated with slower information processing speed and a pattern of cerebral activity that differs from cannabis-naïve individuals, most notably in a bilateral reduction of thalamic activity.

Correlations between MRI and Information Processing Speed in MS: A Meta-Analysis

Objectives. To examine relationships between conventional MRI measures and the paced auditory serial addition test (PASAT) and symbol digit modalities test (SDMT). Methods. A systematic literature review was conducted. Included studies had ≥30 multiple sclerosis (MS) patients, administered the SDMT or PASAT, and measured T2LV or brain atrophy. Meta-analysis of MRI/information processing speed (IPS) correlations, analysis of MRI/IPS significance tests to account for reporting bias, and binomial testing to detect trends when comparing correlation strengths of SDMT versus PASAT and T2LV versus atrophy were conducted. Results. The 39 studies identified frequently reported only significant correlations, suggesting reporting bias. Direct meta-analysis was only feasible for correlations between SDMT and T2LV (r = −0.45, P < 0.001) and atrophy in patients with mixed-MS subtypes (r = −0.54, P < 0.001). Familywise Holm-Bonferroni testing found that selective reporting was not the source of at least half of significant results reported. Binomial tests (P = 0.006) favored SDMT over PASAT in strength of MRI correlations. Conclusions. A moderate-to-strong correlation exists between impaired IPS and MRI in mixed MS populations. Correlations with MRI were stronger for SDMT than for PASAT. Neither heterogeneity among populations nor reporting bias appeared to be responsible for these findings.

The EDSS and Performance on Tests of Visuoconstruction, Working Memory, and Processing Speed in Multiple Sclerosis (P04.113)

Objective: We examined the combined relationship(s) between EDSS scores and working memory, visuoconstruction, and processing speed test performance. Background Expanded Disability Status Scale (EDSS) assesses functional disability, weighted mostly for ambulation. We examined the combined relationship(s) between EDSS scores and working memory, visuoconstruction, and processing speed test performance. Design/Methods: 36 Relapsing/ remitting MS patients (M age= 44.54±12.07) were assessed with the EDSS (M= 3.43±1.90) and neuropsychological tests measuring working memory (WMS-IV Symbol Span, serial order recall), visuoconstruction (total clock drawing errors), and processing speed (WAIS-III Digit Symbol raw score). Results: Simple correlations found that as the EDSS scores increased, performance on the WMS-IV Symbol Span worsen (r= -0.399, p Conclusions: Neuropsychological testing of working memory, visuoconstruction, and processing speed correlate well with the EDSS. This shows that progression of cognitive impairment closely follows the progression of physical impairment. Disclosure: Dr. Tabby has received personal compensation for activities with Biogen Idec as a speaker. Dr. Tabby has received research support from Sanofi-Aventis Pharmaceuticals, Inc. and Bayer Pharmaceuticals Corporation. Dr. Eppig has nothing to disclose. Dr. Nieves has nothing to disclose. Dr. Xu has nothing to disclose. Dr. DeLuca has received personal compensation for activities with Kessler Foundation Research Center and Biogen Idec.Dr. DeLuca has received research support from Biogen Idec. Dr. Libon has nothing to disclose.

Reaction Time and Rapid Serial Processing Measures of Information Processing Speed in Multiple Sclerosis: Complexity, Compounding, and Augmentation

Information processing speed is frequently cited as the primary cognitive domain impacted by multiple sclerosis (MS) and is usually evaluated with reaction time (RT) or rapid serial processing (RSP) measures. The present study compared the efficacy of RT and RSP measures to distinguish between patients with MS (N = 42) and healthy controls (N = 40). The RT measure was patterned after the Computerized Tests of Information Processing and included measures of simple, choice, and semantic RT. The RSP measures consisted of the Symbol Digit Modalities Test (SDMT) and the Stroop Test. Substantial differences in information processing speed between patients and controls were found on all tests, with slightly larger effect sizes for RSP measures than RT measures and for the SDMT than the Stroop Test. Binary logistic regression analyses showed RSP measures performed better than RT measures at distinguishing patients from controls, and likewise, the SDMT score performed better than the scores derived from the Stroop Test. Results are discussed in the context of three effects associated with common measures of processing speed: complexity, compounding, and augmentation.

Evaluating Processing Speed in Multiple Sclerosis: A Comparison of Two Rapid Serial Processing Measures

Processing speed deficits in patients with multiple sclerosis (MS) are usually assessed with tests requiring rapid serial processing. Two such tests were compared here, the Paced Auditory Serial Addition Test (PASAT) and a computerized version of the Stroop test. The purpose of this study was to examine the concurrent validity of processing speed measures derived from the Stroop test and to relate these measures to disability ratings in a sample of 75 patients with relapsing-remitting MS. Patients evidenced slower processing speed than controls on both tests. Processing speed scores on the Stroop test were more closely related to patients’ disability status. These results demonstrate the usefulness of rapid serial processing tests in assessing what is increasingly recognized as the primary cognitive deficit in MS. A less-distressing approach than the item-paced performance required by the PASAT appears to be fully adequate for evaluating this deficit.

Paced Auditory Serial Addition Test : données normatives dans une population française

The Paced Auditory Serial Addition Test (PASAT) is recognized as a sensitive measure of working memory, attention, and information processing speed in multiple sclerosis. The aim of this work was to provide normative data for PASAT in a healthy French population. A total of 360 subjects were recruited from volunteers (24 groups, 15 subjects per group, considering four age classes, three educational levels and gender). The PASAT was administered in a standardized way, by the same psychologist. Normative values were presented expressed as the means and standard deviations of T-score (Z-score*10+50).

Relationships between information processing, depression, fatigue and cognition in multiple sclerosis

The neurobehavioral sequelae of multiple sclerosis (MS) consistently include fatigue, depression and cognitive dysfunction with slower processing figuring prominently. However, processing speed is often confounded with accuracy and the relative contributions of depressed mood and fatigue in influencing speed of processing are difficult to quantify. Therefore, there were three objectives in this study. First, compare processing speed in MS and healthy controls under conditions in which accuracy is not confounded with speed; second, determine the relationships between information processing speed and cognition; third, determine the contributions of clinical depression and fatigue in mediating these relationships. Forty-eight participants with confirmed MS participated. The findings suggested that slower processing was correlated with higher levels of depressed mood, fatigue, lower verbal fluency, fewer words and digits recalled and poorer recall of visual-spatial information. Depression and physical fatigue had the greatest influence on the association between processing speed and more effortful tasks (e.g., immediate word recall and word list learning). Current findings extend previous work by using a more sensitive measure of processing speed and by quantifying the relative contributions of depression and fatigue in mediating relationships between processing speed and cognition.