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Objective: Language lateralization is a major concern in some patients with pharmacoresistant epilepsy who will face surgery; in these patients, hemispheric dominance testing is essential to avoid further complications. The Wada test is considered the gold standard examination for language localization, but is invasive and requires many human and material resources. Functional MRI and tractography with diffusion tensor imaging (DTI) have demonstrated that they could be useful for locating language in epilepsy surgery, but there is no evidence of the correlation between the Wada test and DTI MRI in language dominance., Methods: The authors performed a retrospective review of patients who underwent a Wada test before epilepsy surgery at their institution from 2012 to 2017. The authors retrospectively analyzed fractional anisotropy (FA), number and length of fibers, and volume of the arcuate fasciculus and uncinate fasciculus, comparing dominant and nondominant hemispheres., Results: Ten patients with temporal lobe epilepsy were reviewed. Statistical analysis showed that the mean FA of the arcuate fasciculus in the dominant hemisphere was higher than in the nondominant hemisphere (0.369 vs 0.329, p = 0.049). Also, the number of fibers in the arcuate fasciculus was greater in the dominant hemisphere (881.5 vs 305.4, p = 0.003). However, no differences were found in the FA of the uncinate fasciculus or number of fibers between hemispheres. The length of fibers of the uncinate fasciculus was longer in the dominant side (74.4 vs 50.1 mm, p = 0.05). Volume in both bundles was more prominent in the dominant hemisphere (12.12 vs 6.48 cm3, p = 0.004, in the arcuate fasciculus, and 8.41 vs 4.16 cm3, p = 0.018, in the uncinate fasciculus). Finally, these parameters were compared in patients in whom the seizure focus was situated in the dominant hemisphere: FA (0.37 vs 0.30, p = 0.05), number of fibers (114.4 vs 315.6, p = 0.014), and volume (12.58 vs 5.88 cm3, p = 0.035) in the arcuate fasciculus were found to be statistically significantly higher in the dominant hemispheres. Linear discriminant analysis of FA, number of fibers, and volume of the arcuate fasciculus showed a correct discrimination in 80% of patients (p = 0.024)., Conclusions: The analysis of the arcuate fasciculus and other tract bundles by DTI could be a useful tool for language location testing in the preoperative study of patients with refractory epilepsy.

Introduction: University students tend to suffer from problems of sleep regularity, quantity and quality, which can affect their academic performance. These problems are related to changes typical of the phase of the life cycle in which they find themselves due to maturational, psychosocial development (associated with the processes of individuation and socialisation) and academic factors. The study of the relationship between sleep and academic performance in university students is an area of research of growing interest, which has started to be studied over the last two decades., Aim: To conduct a systematic review of the existing literature on the relationship between sleep and academic performance in university students., Subjects and Methods: The articles included in the PubMed database were selected, following the PRISMA guidelines. Studies evaluating samples of subjects with an average age between 18 and 26 years, published in English or Spanish during the period 2000-2019 were included. Subsequently, the quality of the selected articles was evaluated according to the STROBE standard., Results: Thirty studies were identified, which were grouped according to different aspects of sleep: drowsiness, duration, experience of total sleep deprivation, sleep quality, chronotype, regularity and sleep disorders., Conclusion: The results of these studies suggest that inadequate sleep has a negative effect on the academic performance of university students.

Introduction: Cognitive impairments are common in Parkinson's disease (PD) patients without dementia. These deficits are quite heterogeneous, which makes it difficult to recognize and treat them. For this reason, many authors have attempted to classify patients into more homogeneous groups with diverse results. The present study was designed to analyze the cognitive heterogeneity in PD patients using a novel data-driven approach, latent profile analysis (LPA), to classify patients according to cognitive characteristics. This methodology, which has been used in previous studies focused on motor and psychiatric symptomatology, seems to be better than traditional cluster analysis for the establishment and comparison between different subgroups because it does not require prior decision making about some theoretical or methodological aspects., Method: LPA was applied to 71 PD patients evaluated with a broad neuropsychological battery including different memory and executive function tests. The clusters obtained from the analysis were described by making comparisons with a control group of 51 healthy subjects matched in age, sex, and educational level., Results: The LPA resulted in a four-cluster solution, which could be described as: (a) executive dysfunction (32.4%), (b) memory and executive dysfunction (28.2%), (c) memory dysfunction (23.9%), and (d) noncognitive dysfunction (15.5%). These four PD cluster differ in age and Mini-Mental State Examination (MMSE) score. However, there were no differences between clusters in disease duration, clinical impression of severity index, depression, and cognitive reserve., Conclusions: LPA is a very interesting method for the establishment of more homogeneous groups of PD patients based on their neuropsychological characteristics. Moreover, the distinction between different cognitive profiles will allow us to design interventions better adapted to each patient.

Objective: Executive functions (EF) in multiple sclerosis (MS) have been only partially studied, mainly trough the evaluation of subfunctions. The main objective was to analyse the EF alteration profile in a patients with MS sample., Participants and Methods: Case-control study, 100 patients with MS and 30 controls were evaluated by the following tests: Comprehensive Trail Making Test, Stroop Test, Wisconsin Card Sorting Test, picture completion, letter-number sequencing, comprehension and similarities of the WAIS-III scale, phonological and semantic fluency, zoo map test, temporal judgment and behavioural Dysexecutive Questionnaire (DEX-Q) of the Behavioural Assessment of the Dysexecutive Syndrome. Scores below normative values were considered pathological. Factorial analysis was used to simplify the deficits, and multiple regression and ANOVA statistics were used to analyse the relationship between clinical and cognitive variables., Results: Seventy-four patients had a recurrent-relapsing course, the mean degree of disability by Expanded disability Status Scale (EDSS) was 2.7 and the mean time of evolution was 9.94 years. Eighty-five per cent presented alterations in 3 or more EF tests and 71% in 5 or more. In the factorial analysis, three groups of functions were involved: (i) cognitive flexibility (ii) inhibition and (iii) abstraction ability. Patients with a progressive course and a high EDSS had a significantly worse performance (P < 0.05). The patients showed a low awareness of their deficit in the DEX-Q., Conclusions: Cognitive flexibility, inhibition and abstraction ability were the three components of EF most deficient. The patients with the worst performance were those with progressive forms and a high EDSS., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)