Pain in Multiple System Atrophy a Systematic Review and Meta-Analysis

Background: Individuals with multiple system atrophy (MSA) often complain about pain, nonetheless this remains a poorly investigated non-motor feature of MSA. Objectives: Here, we aimed at assessing the prevalence, characteristics, and risk factors for pain in individuals with MSA. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guidelines, we systematically screened the PubMED, Cochrane, and Web of Science databases for papers published in English until September 30, 2022, combining the following keywords: “pain,” “multiple system atrophy,” “MSA,” “olivopontocerebellar atrophy,” “OPCA,” “striatonigral degeneration,” “SND,” “Shy Drager,” and “atypical parkinsonism.”. Results: The search identified 700 records. Sixteen studies provided information on pain prevalence in cohorts of MSA individuals and were included in a qualitative assessment based on the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Thirteen studies (11 cross-sectional, two longitudinal) scored ≥14 points on QUADAS assessment and were included in a quantitative analysis, pooling data from 1236 MSA individuals. The resulting pooled prevalence of pain in MSA was 67% (95% confidence intervals [CI] = 57%–75%), and significantly higher in individuals with MSA of parkinsonian rather than cerebellar type (76% [95% CI = 63%–87%] vs. 45% [95% CI = 33%–57%], P = 0.001). Pain assessment tools and collected information were highly heterogeneous across studies. Two studies reported pain treatment strategies and found that only every second person with MSA complaining about pain had received targeted treatment. Conclusions: We found that pain is a frequent, but still under-recognized and undertreated feature of MSA. Further research is needed to improve pain detection and treatment in MSA

Mental Addition in Bilinguals: An fMRI Study of Task-Related and Performance-Related Activation

Behavioral studies show that bilinguals are slower and less accurate when performing mental calculation in their nondominant (second; L2) language than in their dominant (first; L1) language. However, little is known about the neural correlates associated with the performance differences observed between bilinguals' 2 languages during arithmetic processing. To address the cortical activation differences between languages, the current study examined task-related and performance-related brain activation during mental addition when problems were presented auditorily in participants' L1 and L2. Eleven Chinese–English bilinguals heard 2-digit addition problems that required exact or approximate calculations. Functional magnetic resonance imaging results showed that auditorily presented multidigit addition in bilinguals activates bilateral inferior parietal and inferior frontal regions in both L1 and L2. Language differences were observed in the form of greater activation for L2 exact addition in the left inferior frontal area. A negative correlation between brain activation and behavioral performance during mental addition in L2 was observed in the left inferior parietal area. Current results provide further evidence for the effects of language-specific experience on arithmetic processing in bilinguals at the cortical level

Alzheimer's disease and mild cognitive impairment: Effects of shifting and interference in simple arithmetic.

The present study investigated arithmetic processing in patients with mild dementia of Alzheimer's type (DAT) and patients with mild cognitive impairment (MCI) without dementia. Arithmetic processing (e.g., 2+3=?, 3 x 4=?) was evaluated in (1) 'blocked' condition (without extra load on attentional and executive functions), in (2) 'mixed' condition (shifting between different operations was required), and in (3) 'Stroop-like' condition (executive control and inhibition of automatic retrieval processes were needed). Both DAT and MCI patients showed intact arithmetic knowledge retrieval from long-term memory in the blocked condition. However, DAT patients were compromised whenever load was put on executive functions, whereas MCI patients succeeded to shift between operations (mixed condition) but had difficulties to inhibit overlearned associations (Stroop-like condition). In line with previous studies, these findings point to the contribution of attentional and executive functions in arithmetic. The present investigation is also of clinical relevance: it suggests that it may be important to assess arithmetic processing not only in blocked presentation but also in mixed presentation. The mixed condition has a high ecological value because it mimics daily-life arithmetic activities (e.g., checking the grocery bill). As indicated by the present results, DAT and MCI patients who are in the normal range at routine neuropsychological (blocked) arithmetic assessments may experience difficulties by extra requirement of non-numerical resources. That means, they possibly process arithmetic not efficiently in daily-life situations