BACKGROUND:Cognitive impairment is common in hemodialysis (HD) patients and increasingly informs clinical decisions, including capacity to consent and the planning of dialysis care. Most estimates rely on the Montreal Cognitive Assessment (MoCA), an instrument strongly dependent on educational attainment. In low-literacy HD populations, this dependence may cause systematic over-identification of impairment and distort apparent risk factors such as sex. We examined how educational attainment shapes MoCA-defined impairment in older HD patients and used the sex difference as a natural experiment to expose the bias. METHODS:This cross-sectional study enrolled 161 patients aged 50 years or older receiving maintenance HD at three Western-region National Guard centers in Saudi Arabia. Impairment was defined as MoCA < 26. We compared mean MoCA and impairment across educational strata; tested for education-related differential item functioning (DIF) across MoCA domains after matching on overall ability; quantified the apparent sex effect by sequential adjustment, formal mediation and within-stratum comparison; estimated the share of the educational score gap recoverable by the standard one-point correction; and tabulated impairment across screening thresholds. Independent determinants were identified by multivariable logistic regression. RESULTS:Impairment affected 107/161 patients (66.5%). Mean MoCA was 17.6 in illiterate patients, 24.1 in those who read/write and 25.5 in college-educated patients (illiterate-college difference 7.9 points). The standard one-point correction offset 13% of this difference; 81% of illiterate patients remained below threshold even after a three-point correction. Education-related DIF was present in the four literacy-loaded domains (attention, executive, orientation, language; all p ≤ 0.006) and absent in the three least literacy-dependent domains (delayed recall, abstraction, naming; all p > 0.3), after matching on overall ability. Women had a higher crude impairment prevalence than men (78.8% vs 57.9%; p = 0.010; crude odds ratio 2.70); this fell to 1.61 (95% CI 0.73-3.53) after adjustment for age and education; education mediated 62% of the sex effect on MoCA score, and the sex difference was non-significant within every education stratum. In sensitivity analyses using lower cutoffs, a residual female association became apparent (adjusted odds ratio 2.66 at < 24 and 2.48 at < 23). In multivariable analysis only older age and lower education were independently associated with impairment (area under the curve 0.76-0.78); no dialysis-related or biochemical variable, including iPTH, was associated. CONCLUSIONS:In this low-literacy HD population, MoCA-defined cognitive impairment was governed by educational attainment, with domain-level evidence of literacy bias, and the apparent female excess was largely explained by educational attainment rather than by sex, although a residual female association persisted at lower cutoffs, consistent with incomplete adjustment for literacy. Because cognitive screening informs consent and care decisions, education-blind use of the MoCA in such settings risks systematic misclassification. Education-aware screening-education-specific norms or cutoffs, attention to literacy-neutral domains, and confirmatory assessment-is preferable to raw thresholds.
The Baking Tray Test (BTT) is sensitive to spatial neglect (SN), but its required materials may limit its inclusion in screening batteries. We developed a modified BTT (mBTT) using portable, easy-to-obtain materials and examined its ability to detect SN in 58 individuals (>6 months post-stroke; 30 right brain damage, 28 left brain damage). Participants completed two cancelation tests (Broken Hearts and 3s Spreadsheet), Line Bisection, Scene Copying, and mBTT. The mBTT detected SN in 29% of participants, comparable to Scene Copying (28%), Line Bisection (36%), and 3s Spreadsheet (22%), and statistically higher than Broken Hearts (14%). Overall, 66% of participants showed SN on at least one test, and 36% on at least two tests. Agreement between mBTT and cancelation tests was not statistically significant. mBTT showed fair, but not substantial, agreement with Line Bisection (κ = 0.24) and Scene Copying (κ = 0.23), indicating that mBTT may identify different aspects of SN and improve screening coverage when used alongside other tests. Because of the materials required for mBTT, the test may be a practical addition to clinical screening batteries. A comprehensive assessment should follow a positive screening result. Future studies with larger clinical samples and age-matched healthy controls are needed to establish norms and diagnostic cutoffs.
Given the interdependence of working memory (WM) and language processing, mitigating cognitive "bottlenecks" remains a critical objective in aphasia rehabilitation to promote functional recovery. This study investigated the comparative efficacy of a language treatment (Phonological Component Analysis; PCA) versus a combined approach integrating PCA and WM training, specifically examining their effects on lexical retrieval and discourse performance. A 65-year-old male with chronic non-fluent aphasia (participant [HY]) was recruited for this single-subject ABAC experimental design, comprising an initial three-session baseline (A1), a phase of PCA-only treatment (B), a secondary three-session baseline (A2), and a phase of combined PCA+WM intervention (C). Primary outcome measures encompassed naming accuracy, WM capacity, and connected speech indices (including lexical, grammatical, and communicative indices). Data analysis was conducted via visual inspection and the Percentage of Non-overlapping Data (PND) metric. Visual analysis revealed that both intervention protocols yielded clinical gains relative to baseline performance. While naming abilities exhibited consistent enhancement across both treatment phases, a notable augmentation in WM capacity was observed specifically during the second phase. Notably, discourse outcomes-incorporating grammatical, semantic, and communicative parameters-demonstrated significant improvement during the initial PCA-only phase, with more modest gains observed during the subsequent combined treatment phase. Post-intervention follow-up indicated that therapeutic gains were either maintained or exhibited marginal continued progress. These findings suggest that integrating WM training into traditional anomia therapy may augment naming and discourse outcomes, Further large-scale research is warranted to elucidate the precise mechanisms by which WM contributes to the remediation of discourse deficits in aphasia.
BACKGROUND:Embedded performance validity tests (PVTs) provide an efficient means of assessing validity in neuropsychological evaluations. Multiple embedded PVTs have been developed for the Rey Auditory Verbal Learning Test (RAVLT), most notably the Effort Score (ES) and Forced Choice (FC) recognition paradigms. However, there is limited research examining whether ES and FC provide nonredundant information, particularly across levels of cognitive impairment. This study examined the independent and combined accuracy of the RAVLT ES and FC embedded PVTs for detecting invalid neuropsychologist test performance. METHODS:Data came from 487 mixed neuropsychiatric outpatients evaluated at an academic medical center who completed the RAVLT and four independent criterion PVTs. Study validity groups were defined invalid based on failure of two or more criterion PVTs (22%). Valid participants were further classified as no impairment, mild, or major neurocognitive disorder. RESULTS:Significant performance differences were observed across all RAVLT scores with large effects. ES and FC were moderately correlated overall, with weaker correlations in the no impairment group. FC was a consistent predictor across all impairment groups, whereas ES showed reduced predictive utility among the mild impairment group. Combined models demonstrated improved classification accuracy compared to either indicator alone. CONCLUSION:RAVLT ES and FC represent distinct but complementary embedded PVTs. FC is more robust in genuine cognitive impairment and should be prioritized in impaired populations, whereas ES provides incremental value in cognitively intact individuals. These findings support the use of multiple embedded RAVLT PVTs in clinical practice.
OBJECTIVE:The aim of this study was to evaluate the central auditory processing abilities of patients with Obstructive Sleep Apnea Syndrome (OSAS). METHODS:A total of 86 individuals aged between 20 and 55 years, with normal pure-tone averages and no history of any pathology that could affect hearing, were included in the study. The study group consisted of 43 individuals diagnosed with OSAS by polysomnography, while the control group comprised 43 individuals without an OSAS diagnosis or related symptoms. All participants underwent pure-tone audiometry test, speech reception threshold (SRT), speech discrimination score (SDS), Frequency Pattern Test (FPT), Duration Pattern Test (DPT), Gaps-in-Noise Test (GIN), and Masking Level Difference (MLD) test. RESULTS:According to the findings, pure-tone thresholds in the study group were significantly higher than those of the control group bilaterally across the 125-8000 Hz frequency range, except at 2000 Hz. The mean SRT values were also significantly higher in the study group compared to the control group. No significant difference was found between the groups in terms of SDS. The mean score of the study group in the DPT was significantly higher than that of the control group. No significant differences were observed between the groups in the FPT, GIN, or MLD tests. However, in the SPT, FPT, and GIN tests, the OSAS group exhibited poorer performance compared to the control group. CONCLUSION:In conclusion, both peripheral hearing and central auditory processing abilities were found to be adversely affected in individuals with Obstructive Sleep Apnea Syndrome.
