Attention and processing speed tests: Normative data for Spanish-speaking adults in the United States.

BACKGROUND: Hispanics/Latinos are the largest racial/ethnic group among underrepresented populations in the U.S. and multiple sociodemographic, cultural, and linguistic factors have been found to impact their performances on cognitive testing. Despite this, few normative data are available for the heterogeneous Spanish-speaking population in the U.S. OBJECTIVE: To generate normative data on the Trail-Making Test (TMT), Bells Test, Symbol-Digit Modalities Test (SDMT), and the Brief Test of Attention (BTA) for Spanish speakers residing in the U.S. METHODS: The sample included 245 Spanish-speaking individuals aged 18- 80 from eight states across the U.S. (California, Connecticut, Florida, Indiana, New Jersey, Oregon, Virginia, and Wisconsin). Participants were administered attention and processing speed measures as part of a comprehensive neuropsychological battery. We used a Bayesian regression approach to estimate normative data, including covariates found to be important for predicting performances on measures of attention and processing speed. RESULTS: Sociodemographic factors including education, time in the U.S., acculturation, age, and/or sex had differential effects on the TMT-A, TMT-B, SDMT, and the BTA whereas the Bells Test was not influenced by any of these sociodemographic factors. CONCLUSION: Our findings indicate that while sex, age, and educational attainment are important factors to consider, language and acculturation can also influence attention and processing speed performances among Spanish speakers in the U.S.

Absence of BOLD adaptation in chronic fatigue syndrome revealed by task functional MRI.

Neurological symptoms are central to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), yet its underlying neurophysiological mechanisms remain elusive. We examined a neglected aspect of task-based functional MRI, focusing on how blood oxygenation level-dependent (BOLD) signals alter during cognitive tasks in ME/CFS. This prospective observational study utilised MRI scans on ME/CFS participants and healthy controls (HCs) with sedentary lifestyles (ACTRN12622001095752). Participants completed two blocks of a Symbol Digit Modalities Test, with 30 trials per block split into two sets. The fMRI signal changes between blocks and sets were compared within and between groups. Thirty-four ME/CFS participants (38 years ± 10; 27 women) and 34 HCs (38 ± 10; 27 women), were evaluated. In the second task block, ME/CFS participants exhibited increased activation in the right postcentral gyrus, contrasting with decreased activation in multiple regions in HCs. These results were further confirmed by significantly higher bilateral dynamic changes (2nd vs 1st set) in the motor, sensory and cognitive cortex in ME/CFS compared to HCs and significant correlations between those changes in the left primary motor cortex with fatigue severities. BOLD adaptation, potentially improving energy economy, was absent in ME/CFS, which may provide an underlying neurophysiological process in ME/CFS.

Impact of Acute Dopamine Replacement on Cognitive Function in Parkinson's Disease.

BACKGROUND: PD causes striatal dopaminergic denervation in a posterior/dorsal to anterior/ventral gradient, leaving motor and associative cortico-striato-pallido-thalamic loops differentially susceptible to hyperdopaminergic effects with treatment. As the choice and titration of symptomatic PD medications are guided primarily by motor symptoms, it is important to understand their cognitive implications. OBJECTIVE: To investigate the effects of acute dopaminergic medication administration on executive function in Parkinson's disease (PD). METHODS: Participants with idiopathic PD were administered the oral Symbol Digit Modalities Test (SDMT; n = 181) and the Stroop test (n = 172) in the off-medication and "best on" medication states. ANCOVA was used to test for differences between off-medication and on-medication scores corrected for age and years of education. RESULTS: After administration of symptomatic medications, scores worsened on the SDMT (F = 11.70, P < 0.001, d = -0.13), improved on the Stroop color (F = 26.89, P < 0.001, d = 0.184), word (F = 6.25, P = 0.013, d = 0.09), and color-word (F = 13.22, P < 0.001, d = 0.16) test components, and the Stroop difference and ratio-based interference scores did not significantly change. Longer disease duration correlated with lower scores on the SDMT, Stroop color, word, and color-word scores; however, longer disease duration and higher levodopa-equivalents correlated with higher Stroop difference-based interference scores. CONCLUSIONS: Symptomatic medication differentially affects performance on two cognitive tests in PD. After acute treatment, core Stroop measures improved, Stroop interference was unchanged, and SDMT performance worsened, likely reflecting complex changes in processing speed and executive function related to acute treatment. When considering motor symptom therapies in PD, an individual's cognitive demands and expectations, especially regarding executive function, should be considered.

Symbol Digit Modalities Test in progressive multiple sclerosis.

INTRODUCTION: The Symbol Digit Modalities Test (SDMT) is a highly sensitive neuropsychological tool used for the assessment of information processing speed (IPS) in various neurological disorders. STATE OF THE ART: In this review, we have focused on the current knowledge regarding the use of SDMT selectively in the evaluation of progressive multiple sclerosis (PMS) patients. A literature review was performed regarding the application of SDMT in PMS, with a focus on the primary progressive and secondary progressive subtypes. Relationships of diverse disease-associated factors with SDMT have been described, including disease course, imaging findings, molecular biomarkers, treatment and others. CLINICAL IMPLICATIONS: SDMT is a very useful and easily applicable instrument in the diagnostic armamentarium of neurologists and neuropsychologists. It is especially valuable in the evaluation of PMS patients, in whom the prevalence of IPS deficits is higher than in relapsing-remitting multiple sclerosis subjects or in healthy individuals. FUTURE DIRECTIONS: An emphasis should be laid on larger study groups and differentiating between individual PMS subtypes and their separate analysis in the context of cognitive assessment.

Performance of the Activities and Participation component of International Classification of Functioning, Disability and Health Sleep Disorders Brief Core Set in patients with obstructive sleep apnea.

Background: Limitation of daily activities and impairment of working memory have received less attention in the clinical diagnosis and prognostic assessment of obstructive sleep apnea (OSA). In this study, the Activities and Participation component of the International Classification of Functioning, Disability and Health (ICF) Sleep Disorders Brief Core Set was evaluated for its performance in predicting impaired work ability in OSA patients. Methods: A total of 221 subjects were recruited into this cross-sectional study. ICF Sleep Disorders Brief Core Set, polysomnography, and neuropsychological tests were applied for data acquisition. Data analysis was performed by regression analysis and receiver operating characteristic (ROC) construction. Results: The scores for the component Activities and Participation were significantly different between the no OSA/OSA group, and were elevated as the severity of OSA increased. Scores were positively correlated with apnea-hypopnea index (AHI), trail making test (TMT), and negatively correlated with symbol digit modalities test (SDMT) correct. The component Activities and Participation performed better with the threshold of 4 in the prediction of impaired attention and work ability in severe OSA [AHI ≥30 events/h, bottom 10% of TMT part B (TMTb) scores as the diagnostic criteria], with area under the curve, sensitivity and specificity as 0.909, 71.43% and 96.72%, respectively. Conclusions: The Activities and Participation component of the ICF Sleep Disorders Brief Core Set could have the potential to predict the impairment of attention and work ability in OSA patients. It provides a new perspective for the identification of OSA patients' disturbances in daily activities and improving the overall assessment level.

Hepatitis C Virus (HCV) Infection and Neurocognitive Impairment in Subjects with Mild Liver Disease.

Hepatitis C virus (HCV) infection is a leading cause of liver cirrhosis, hepatocellular carcinoma, and liver-related deaths. It is estimated that 40-74% of patients with hepatitis C will experience at least one extrahepatic manifestation within their lifetime. The finding of HCV-RNA sequences in post-mortem brain tissue raises the possibility that HCV infection may affect the central nervous system and be the source of subtle neuropsychological symptoms, even in non-cirrhotic. Our investigation aimed to evaluate whether asymptomatic, HCV-infected subjects showed cognitive dysfunctions. Twenty-eight untreated asymptomatic HCV subjects and 18 healthy controls were tested using three neuropsychological instruments in a random sequence: Symbol Digit Modalities Test (SDMT), Controlled Oral Word Association Test (COWAT), and Continuous Visual Attention Test (CVAT). We performed depression screening, liver fibrosis assessment, blood tests, genotyping, and HCV-RNA viral load. A MANCOVA and univariate ANCOVAS were performed to examine group differences (HCV vs. healthy controls) in four scores of the CVAT (omission errors, commission errors, reaction time-RT, and variability of RT-VRT), and the scores derived from the SDMT, and the COWAT. A discriminant analysis was performed to identify which test variables effectively discriminate HCV-infected subjects from healthy controls. There were no group differences in the scores of the COWAT, SDMT, and in two variables of the CVAT (omission and commission errors). In contrast, the performance of the HCV group was poorer than the controls in RT (p = 0.047) and VRT (p = 0.046). The discriminant analysis further indicated that the RT was the most reliable variable to discriminate the two groups with an accuracy of 71.7%. The higher RT exhibited by the HCV group may reflect deficits in the intrinsic-alertness attention subdomain. As the RT variable was found to be the best discriminator between HCV patients and controls, we suggest that intrinsic-alertness deficits in HCV patients may affect the stability of response times increasing VRT and leading to significant lapses in attention. In conclusion, HCV subjects with mild disease showed deficits in RT and intraindividual VRT as compared to healthy controls.

Correlation between cognitive impairment and serum phosphorylated tau181 protein in patients with preeclampsia.

Objective: To study the cognitive function status, serum phosphorylated tau181 (P-tau181) protein level, and total tau (T-tau) protein level in patients with preeclampsia (PE), pregnant healthy controls (PHCs), and non-pregnant healthy controls (NPHCs), and to research their feasibility as serum biomarkers for evaluating cognitive functional impairment in PE patients. Methods: Sixty-eight patients with PE, 48 NPHCs, and 30 PHCs were included. Cognitive functional status was assessed using standardized Symbol Digit Modalities Test (SDMT) and Montreal Cognitive Assessment (MoCA) scales. Enzyme-linked immunosorbent assay (ELISA) was used to detect the level of serum P-tau181 and T-tau protein. The concentration of serum P-tau181 and T-tau protein were compared by one-way analysis of variance in the three groups of subjects. The correlation between P-tau181, T-tau, and SDMT was explore by multiple linear regression analysis. The areas under the receiver operating characteristic (ROC) curves of serum P-tau181 and SDMT were calculated to predict the cognitive level of subjects. Results: PE patients significantly had lower scores on SDMT (47.97 ± 7.54) and MoCA (28.00 ± 2.00) than normotensive PHCs (30.00 ± 1.25, 54.73 ± 8.55, respectively). The significant difference was found in serum P-tau181 protein levels among the three groups [H(K) = 19.101, P < 0.001]. Serum P-tau181 was thicker in PE patients than PHCs or NPHCs (both P < 0.05). According to the ROC curve, T-tau had no statistical significance in predicting the ability of cognizance, while P-tau181 and SDMT had. The DeLong test showed that P-tau181 was better than T-tau in predicting the ability of cognizance (P < 0.05). Conclusion: The patients with PE have occurred the decline of cognitive function during pregnancy. The high level of serum P-tau181 can be used as a clinical laboratory indication for non-invasive assessment of cognitive functional impairment in PE patients.

High levels of kappa free light chain synthesis predict cognitive decline in relapsing-remitting multiple sclerosis.

Background: Evolving evidence suggests that measurement of cerebrospinal fluid (CSF) kappa free light chain (KFLC) synthesis has high diagnostic sensitivity and specificity for multiple sclerosis (MS), but its prognostic ability is less investigated. The usefulness of KFLC in predicting cognitive impairment (CI) is still unknown. Methods: In a monocentric longitudinal retrospecitve cohort study, KFLC-index ([CSF KFLC/serum KFLC]/[CSF albumin/serum albumin]) measured by latex-enhanced immunonephelometry was prospectively determined as part of the diagnostic workup in patients with early relapsing-remitting MS (RRMS, n=77). The ability of KFLC-index to predict information processing speed (IPS) worsening as assessed with the symbol digit modalities test (SDMT) was investigated in univariable and multivariable models. Results: In patients with KFLC-index>100 (n=31), 11 subjects (35.5%) showed reduced SDMT scores by ≥8 points at follow-up (mean follow-up time 7.3 ± 2.6 years), compared with their baseline scores (p=0.01). Baseline KFLC-index>100 was strongly associated with a higher hazard of SDMT score reduction at follow-up (adjusted hazard ratio 10.5, 95% confidence interval 2.2-50.8, p=0.003; median time to SDMT reduction 7 years). Conclusion: Intrathecal KFLC synthesis has become an attractive diagnostic tool for MS. We show for the first time that in a real-world setting of early RRMS, KFLC-index predicted cognitive decline. Whether this predictive ability of KFLC-index also concerns other cognitive domains than IPS, warrants further investigations.

Neurocognitive impairment in multiple sclerosis and its association with thiol-disulfide homeostasis and ischemia-modified albumin.

This study aimed to assess the possible association between cognitive impairment and two important biochemical biomarkers of oxidative stress, thiol-disulfide homeostasis (TDH), and ischemia-modified albumin (IMA) in patients with multiple sclerosis (MS). This study included 85 patients with MS (38 treatment-naïve relapsing-remitting MS (RRMS), 31 RRMS on fingolimod therapy, and 16 secondary progressive MS (SPMS)) and 33 healthy controls. Cognitive evaluation was carried out by applying the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) test battery and the scores were adjusted for age and years of education. Plasma TDH was assessed using an automated method and plasma IMA levels were determined using the cobalt-albumin binding assay. Plasma native thiol and total thiol levels were significantly decreased in patients with SPMS when compared with the naïve patients and healthy controls. Cognitive impairment was detected in 47.4% of naïve patients, 64.5% of patients on fingolimod therapy, and 80% of patients with SPMS. Naïve patients or patients on fingolimod therapy who were cognitively impaired had significantly decreased levels of native thiol and total thiol compared to the cognitively normal patients. Logistic regression analysis revealed total thiol and native thiol to be significantly associated with cognitive impairment in naïve patients and patients on fingolimod therapy. Significant correlations were determined between BICAMS scores, TDH, IMA, clinical indices of disease severity (EDSS and MSSS), and magnetic resonance imaging parameters. This study has shown for the first time that plasma TDH parameters are associated with cognitive impairment in MS.

The relation between the symbol digit modalities test, fatigue, depression, and anxiety symptoms in a Belgian MS cohort.

BACKGROUND: Multiple sclerosis (MS) is associated with high prevalence of cognitive impairment, ranging from 40 to 80%. The purpose of this single-center retrospective study was to examine the relation between cognitive function, as measured by Symbol Digit Modalities Test (SDMT), with fatigue, anxiety, and depression symptoms in a Belgian cohort of patients with MS. METHODS: Sociodemographic and clinical data were analyzed in 66 (F:40, M:26) Belgian patients with a diagnosis of MS. The cognitive function was assessed with the oral version of SDMT, depression and anxiety symptoms with the Hospital Anxiety and Depression scale (HAD), fatigue symptoms with the French valid version of the Fatigue Impact Scale in MS (EMIF-SEP), which is a scale composed of four dimensions (cognitive, physical, social, and psychological) allowing a multidimensional evaluation of fatigue. RESULTS: The multivariate linear regression analysis demonstrated that lower SDMT scores were associated with higher EDSS score and psychological dimension of fatigue symptoms. No association were found between SDMT and anxiety or depression symptoms. Conversely, higher depression and anxiety symptoms were associated with higher total fatigue symptoms, but lower physical dimension of fatigue symptoms. Higher anxiety symptoms were also independently associated with higher social dimension of fatigue symptoms. CONCLUSION: A complex relationship exists between cognitive performance, fatigue, and neuropsychiatric symptoms in Belgian people with MS. The level of disability and fatigue adversely affects the cognitive function in MS, whereas depression and anxiety seem to not have a significant effect. A more complex relationship exists between fatigue and neuropsychiatric symptoms, with a divergent interplay between the different dimensions of fatigue that supports the multidimensional approach to assessing fatigue in MS.

Prediction of the information processing speed performance in multiple sclerosis using a machine learning approach in a large multicenter magnetic resonance imaging data set.

Many patients with multiple sclerosis (MS) experience information processing speed (IPS) deficits, and the Symbol Digit Modalities Test (SDMT) has been recommended as a valid screening test. Magnetic resonance imaging (MRI) has markedly improved the understanding of the mechanisms associated with cognitive deficits in MS. However, which structural MRI markers are the most closely related to cognitive performance is still unclear. We used the multicenter 3T-MRI data set of the Italian Neuroimaging Network Initiative to extract multimodal data (i.e., demographic, clinical, neuropsychological, and structural MRIs) of 540 MS patients. We aimed to assess, through machine learning techniques, the contribution of brain MRI structural volumes in the prediction of IPS deficits when combined with demographic and clinical features. We trained and tested the eXtreme Gradient Boosting (XGBoost) model following a rigorous validation scheme to obtain reliable generalization performance. We carried out a classification and a regression task based on SDMT scores feeding each model with different combinations of features. For the classification task, the model trained with thalamus, cortical gray matter, hippocampus, and lesions volumes achieved an area under the receiver operating characteristic curve of 0.74. For the regression task, the model trained with cortical gray matter and thalamus volumes, EDSS, nucleus accumbens, lesions, and putamen volumes, and age reached a mean absolute error of 0.95. In conclusion, our results confirmed that damage to cortical gray matter and relevant deep and archaic gray matter structures, such as the thalamus and hippocampus, is among the most relevant predictors of cognitive performance in MS.

Trail Making Test Could Predict Impairment in Cognitive Domains in Patients with Multiple Sclerosis: A Study of Diagnostic Accuracy.

OBJECTIVE: Cognitive impairment (CI) and executive dysfunction (ED) are prevalent in patients with multiple sclerosis (PwMS). The Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) is the gold standard neuropsychological battery (NPB) for detecting CI. Delis-Kaplan Executive Function System (DKEFS) NPB evaluates ED. We aimed to find practical test(s) from DKEFS with acceptable diagnostic utility for early detection of impairment in cognitive and executive domains. METHODS: Cognitive and executive tasks, physical disability, and depression scores of 30 PwMS were assessed (17 women, age: 38.1). Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and Controlled Oral Word Association Test (COWAT) from MACFIMS and Trail Making Test (TMT), Design Fluency Test (DFT), and Verbal Fluency Test (VFT) from DKEFS were selected. The association between patients' characteristics and performance in tests, and diagnostic accuracy of DKEFS tests in detecting impairment in cognitive tasks were evaluated, using Pearson correlation and receiver operator characteristic curve analyses, respectively. RESULTS: A significant correlation was found between disease duration and SDMT and TMT subtests. Expanded Disability Status Scale was significantly related to SDMT, VFT-switching, and TMT subtests. Beck Depression Inventory was significantly related to DFT. TMT-switching detected abnormalities in SDMT and PASAT with 100% sensitivity, 93.3% (for SDMT), and 85.7% specificity (for PASAT). TMT-letter showed 100% sensitivity and 90% specificity in identifying abnormalities in COWAT. CONCLUSIONS: TMT, particularly the switching condition, is a practical paper-based test that could predict impairment in cognitive tasks. Clinicians may use TMT as a screening tool among PwMS.

The symbol digit modalities test and the paced auditory serial addition test involve more than processing speed.

BACKGROUND: Slowed processing speed is the most frequently reported cognitive deficit for people with multiple sclerosis (MS). However, measures used to assess processing speed may also recruit other cognitive abilities. The present objective was to determine the contributions of different cognitive functions to performance on two commonly used processing speed measures: the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT). METHODS: Adults with relapsing-remitting MS (n = 70) and controls (n = 72) completed the SDMT, PASAT, and multiple measures assessing processing speed, working memory, and learning. Hierarchical regression analyses were used to examine the contributions of MS, processing speed, working memory, learning, and all possible interactions among factors to SDMT and PASAT scores. RESULTS: Processing speed and working memory generally contributed to performance on the SDMT and PASAT, with learning additionally contributing to SDMT performance. However, significant interactions revealed processing speed did not influence PASAT performance for individuals with high working memory ability whereas processing speed became increasingly more important as working memory declined to average and low levels. Further, processing speed was associated with SDMT performance for patients with MS but not controls. CONCLUSIONS: These findings support a multifactorial interpretation of the SDMT and PASAT, which facilitates their usefulness as screening measures for cognitive decline but prevents them from identifying which specific cognitive functions are affected.

Symbol digit modalities test predicts decline of off-road driving ability in Japanese patients with multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a chronic progressing neurological disease with exacerbations and remissions. Patients with MS can show a variety of neurological symptoms. Cognitive decline is noticed as one of them and is related with deterioration of daily life quality in a clinical practice. Driving a car is one of the common activities required in daily life and is also an important issue in MS patients. METHODS: To clarify the relationship between cognitive function and driving ability in MS patients, the symbol digit modalities test (SDMT) and a driving simulator were evaluated. We enrolled 24 patients with MS (5 males, 19 females, 39.04 ± 8.27 years old) and age- and sex-matched 24 healthy controls (5 males, 19 females, 40.54 ± 9.78 years old) in this study. They underwent the SDMT and also used a driving simulator to measure a total of 12 response values related to driving ability. In order to evaluate the relationship between SDMT and driving ability, MS patients were divided into two groups according to the median SDMT score: group A (SDMT 51 or more) and group B (SDMT less than 51). The data were statistically analyzed among control group, MS group A, and MS group B using Jonkheere-Terpstra trend test and Bonferroni's multiple comparison test. RESULTS: The group with higher scores on the SDMT tended to have significantly higher driving performance. Multiple comparison analysis among three groups showed that the reaction values for speed of response behavior were significantly higher in MS group B than control group. CONCLUSION: This study revealed a relationship between driving abilities and SDMT scores. Clinical evaluation using the SDMT may help to detect cognitive decline and to make a decision on driving a car in patients with MS.

Test-Retest Reliability and Minimal Detectable Change of Four Cognitive Tests in Community-Dwelling Older Adults.

BACKGROUND: Cognitive test-retest reliability measures can be used to evaluate meaningful changes in scores. OBJECTIVE: This analysis aimed to develop a comprehensive set of test-retest reliability values and minimal detectable change (MDC) values for a cognitive battery for community-dwelling older individuals in Australia and the U.S., for use in clinical practice. METHODS: Cognitive scores collected at baseline and year 1, in the ASPirin in Reducing Events in the Elderly clinical trial were used to calculate intraclass correlation coefficients (ICC) for four tests: Modified Mini-Mental State examination (3MS), Hopkins Verbal Learning Test-Revised (HVLT-R), single-letter Controlled Oral Word Association Test (COWAT-F), and Symbol Digit Modalities Test (SDMT). 16,956 participants aged 70 years and over (65 years and over for U.S. minorities) were included. ICCs were used to calculate MDC values for eight education and ethno-racial subgroups. RESULTS: All four cognitive tests had moderate (ICC > 0.5) to good (ICC > 0.7) test-retest reliability. ICCs ranged from 0.53 to 0.63 (3MS), 0.68 to 0.77 (SDMT), 0.56 to 0.64 (COWAT-F), 0.57 to 0.69 (HVLT-R total recall), and 0.57 to 0.70 (HVLT-R delayed recall) across the subgroups. MDC values ranged from 6.60 to 9.95 (3MS), 12.42 to 15.61 (SDMT), 6.34 to 8.34 (COWAT-F), 8.13 to 10.85 (HVLT-R total recall), and 4.00 to 5.62 (HVLT-R delayed recall). CONCLUSION: This large cohort of older individuals provides test-retest reliability and MDC values for four widely employed tests of cognitive function. These results can aid interpretation of cognitive scores and decline instead of relying on cross-sectional normative data alone.

Measuring cognitive function by the SDMT across functional domains: Useful but not sufficient.

BACKGROUND: The Symbol Digit Modalities Test (SDMT) is a common screen of cognitive function for people with Multiple Sclerosis (pwMS) but growing acknowledgement that people with cognitive impairment are a heterogeneous population suggests that a single screen may provide limited information. OBJECTIVE: To assess the adequacy of the SDMT in capturing impairment across specific cognitive domains as measured by a multi-domain cognitive assessment battery (CAB, NeuroTrax). METHODS: 113 pwMS were assessed with SDMT and the CAB. Cognitive impairment in each CAB domain was defined as ≥1.5 SD below the normalized mean. Logistic regression models were fit for each CAB domain with domain-specific cognitive impairment as the outcome and SDMT as the predictor, and a classifier created by selecting cutpoints using the Youden Index. Model performance was assessed by predicting domain-specific cognitive impairment in an independent data set consisting of 81 pwMS. RESULTS: SDMT was a significant predictor of cognitive impairment in all outcomes considered (Odds Ratio: 0.885-0.950), but prediction metrics such as area under the receiver operating curve (AUC) were modest (0.623-0.778), and the alignment between observed/predicted impairment was less than optimal. CONCLUSION: The SDMT is not sufficient to differentiate between impaired and non-impaired pwMS across several cognitive domains.

Clinical relevance of the radiation dose bath in lower grade glioma, a cross-sectional pilot study on neurocognitive and radiological outcome.

Aim: To investigate the clinical relevance of the radiotherapy (RT) dose bath in patients treated for lower grade glioma (LGG). Methods: Patients (n = 17) treated with RT for LGG were assessed with neurocognitive function (NCF) tests and structural Magnetic Resonance Imaging (MRI) and categorized in subgroups based on tumour lateralisation. RT dose, volumetric results and cerebral microbleed (CMB) number were extracted for contralateral cerebrum, contralateral hippocampus, and cerebellum. The RT clinical target volume (CTV) was included in the analysis as a surrogate for focal tumour and other treatment effects. The relationships between RT dose, CTV, NCF and radiological outcome were analysed per subgroup. Results: The subgroup with left-sided tumours (n = 10) performed significantly lower on verbal tests. The RT dose to the right cerebrum, as well as CTV, were related to poorer performance on tests for processing speed, attention, and visuospatial abilities, and more CMB.In the subgroup with right-sided tumours (n = 7), RT dose in the left cerebrum was related to lower verbal memory performance, (immediate and delayed recall, r = -0.821, p = 0.023 and r = -0.937, p = 0.002, respectively), and RT dose to the left hippocampus was related to hippocampal volume (r = -0.857, p = 0.014), without correlation between CTV and NCF. Conclusion: By using a novel approach, we were able to investigate the clinical relevance of the RT dose bath in patients with LGG more specifically. We used combined MRI-derived and NCF outcome measures to assess radiation-induced brain damage, and observed potential RT effects on the left-sided brain resulting in lower verbal memory performance and hippocampus volume.

A much needed metric: Defining reliable and statistically meaningful change of the oral version Symbol Digit Modalities Test (SDMT).

BACKGROUND: The Symbol Digit Modalities Test (SDMT) has been recommended for use in clinical trials and outcome studies to monitor cognitive change. However, defining what is a meaningful change has been elusive for several years. OBJECTIVE: The present investigation aimed to develop methods for assessing individual-level statistically significant change on the SDMT - reliable change indices (RCIs) and standardized regression-based (SRB) equations. METHODS: A total of 219 healthy individuals completed the oral version SDMT at baseline, 6-month and 1-year follow-up. RESULTS: The SDMT demonstrated high reliability across all time points (r's = 0.83 to 0.86). Reliable change scores of 7, 8, and 10 points for the 6-month intervals represented statistically meaningful change at the 0.70, 0.80, and 0.90 confidence intervals, respectively. Over 1-year, a difference of 8, 10, and 12 was statistically meaningful at the 0.70, 0.80, and 0.90 confidence intervals, respectively. SRB equations are also provided taking into account additional factors found to be predictive of SDMT scores over time. CONCLUSION: Clinicians frequently denote a decline of 4 points on the SDMT as meaningful. Results in this large normative sample show that higher cut-points are needed to demonstrate statistically significant decline at the individual level. RCIs are provided for 6 month and one year assessment, which is typical in clinical practice and trials. SRB equations are also provided for use when applicable and may provide a more precise assessment of meaningful change.