Information processing speed and attention in multiple sclerosis: Reconsidering the Attention Network Test (ANT)

2015 ◽  
Vol 37 (5) ◽  
pp. 518-529 ◽  
Author(s):  
Alexandra K. Roth ◽  
Douglas R. Denney ◽  
Sharon G. Lynch
2013 ◽  
Vol 19 (5) ◽  
pp. 551-558 ◽  
Author(s):  
Magdalena Wojtowicz ◽  
Antonina Omisade ◽  
John D. Fisk

AbstractImpairments in attention and information processing speed are common in multiple sclerosis (MS) and may contribute to impairments of other cognitive abilities. This study examined attentional efficiency, information processing speed and intra-individual variability in response speed using the Attention Network Test-Interactions (ANT-I) in mildy-affected patients with MS. Thirty-one patients with relapsing-remitting MS and 30 age, sex, and education-matched controls completed the ANT-I, as well as the Paced Auditory Serial Attention Test (PASAT), as a standard clinical measure of information processing efficiency. As expected, patients with MS were slower in reaction time performance on the ANT-I and had poorer performance on the PASAT compared to controls. Patients with MS also demonstrated poorer efficiency in their executive control of attention on the ANT-I, suggesting difficulties with top-down allocation of attention. In addition, the MS group demonstrated greater intra-individual variability in the responses to the ANT-I even when their slower overall response time and other factors such as practice were accounted for. Intra-individual variability was found to best predict group membership compared to PASAT scores and other ANT-I scores. These results suggest that intra-individual variability may provide sensitive, unique and important information regarding cognitive functioning in early MS. (JINS, 2013, 19, 1–8)


2013 ◽  
Vol 19 (5) ◽  
pp. 613-620 ◽  
Author(s):  
Emily M. Owens ◽  
Douglas R. Denney ◽  
Sharon G. Lynch

AbstractPrevious studies show that MS patients take longer than healthy controls to plan their solutions to Tower of London (TOL) problems but yield conflicting results regarding the quality of their solutions. The present study evaluated performance under untimed or timed conditions to assess the possibility that differences in planning ability only occur when restrictions in solution times are imposed. MS patients (n = 39) and healthy controls (n = 43) completed a computerized version of the TOL under one of two conditions. In the untimed condition, participants were allowed as much time as needed on each problem. In the timed condition, limits were imposed on solution times and time remaining was displayed with each problem. Patients exhibited longer planning times than controls, and the disparity between groups increased with problem difficulty. Planning performance depended upon condition. In the untimed condition, patients and controls performed equally well. When solution times were restricted, however, patients solved fewer problems than controls. MS patients’ planning ability is intact when permitted sufficient time to formulate the required plan. Deficiencies in planning are only evident when time is restricted, and, therefore, are more accurately considered a relative consequence of disease-related problems in information processing speed. (JINS, 2013, 19, 1–8)


Neurology ◽  
2019 ◽  
Vol 93 (8) ◽  
pp. e733-e746 ◽  
Author(s):  
Laura De Giglio ◽  
Francesca De Luca ◽  
Flavia Gurreri ◽  
Ilaria Ferrante ◽  
Luca Prosperini ◽  
...  

ObjectiveTo test a possible benefit of dalfampridine on information processing speed (IPS), a key function for cognitive impairment (CogIm) in multiple sclerosis (MS).MethodsIn this randomized, double-blind, placebo-controlled trial, we included patients with a score on the Symbol Digit Modalities Test (SDMT) under the 10th percentile of the reference value. Patients were randomized in a 2:1 ratio to receive dalfampridine 10 mg or placebo twice daily for 12 weeks. They underwent a comprehensive neuropsychological evaluation at screening (T0), at the end of treatment (T1), and after a 4-week follow-up (T2). The primary endpoint was improvement in SDMT.ResultsOut of 208 patients screened, 120 were randomized to receive either dalfampridine (n = 80) or placebo (n = 40). At T1, the dalfampridine group presented an increase of SDMT scores vs placebo group (mean change 9.9 [95% confidence interval (CI) 8.5–11.4] vs 5.2 [95% CI 2.8–7.6], p = 0.0018; d = 0.60 for raw score; and 0.8 [95% CI 0.6–1] vs 0.3 [95% CI 0.0–0.5], p = 0.0013; d = 0.61 for z scores; by linear mixed model with robust standard error). The improvement was not sustained at T2. A beneficial effect of dalfampridine was observed in the Paced Auditory Serial Addition Test and in cognitive fatigue.ConclusionDalfampridine could be considered as an effective treatment option for IPS impairment in MS.Trial registration2013-002558-64 EU Clinical Trials Register.Classification of evidenceThis study provides Class I evidence that for patients with MS with low scores on the SDMT, dalfampridine improves IPS.


2014 ◽  
Vol 20 (11) ◽  
pp. 1453-1463 ◽  
Author(s):  
Magdalena Wojtowicz ◽  
Erin L Mazerolle ◽  
Virender Bhan ◽  
John D Fisk

Background: Patients with multiple sclerosis (MS) demonstrate slower and more variable performance on attention and information processing speed tasks. Greater variability in cognitive task performance has been shown to be an important predictor of neurologic status and provides a unique measure of cognitive performance in MS patients. Objectives: This study investigated alterations in resting-state functional connectivity associated with within-person performance variability in MS patients. Methods: Relapsing–remitting MS patients and matched healthy controls completed structural MRI and resting-state fMRI (rsfMRI) scans, as well as tests of information processing speed. Performance variability was calculated from reaction time tests of processing speed. rsfMRI connectivity was investigated within regions associated with the default mode network (DMN). Relations between performance variability and functional connectivity in the DMN within MS patients were evaluated. Results: MS patients demonstrated greater reaction time performance variability compared to healthy controls ( p<0.05). For MS patients, more stable performance on a complex processing speed task was associated with greater resting-state connectivity between the ventral medial prefrontal cortex and the frontal pole. Conclusions: Among MS patients, greater functional connectivity between medial prefrontal and frontal pole regions appears to facilitate performance stability on complex speed-dependent information processing tasks.


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