Impaired dual-task gait in Parkinson's disease is associated with brain morphology changes.

In Parkinson's disease (PD), impaired gait and cognition affect daily activities, particularly in the more advanced stages of the disease. This study investigated the relationship between gait parameters, cognitive performance, and brain morphology in patients with early untreated PD. 64 drug-naive PD patients and 47 healthy controls (HC) participated in the study. Single- and dual-task gait (counting task) were examined using an expanded Timed Up & Go Test measured on a GaitRite walkway. Measurements included gait speed, stride length, and cadence. A brain morphometry analysis was performed on T1-weighted magnetic resonance (MR) images. In PD patients compared to HC, gait analysis revealed reduced speed (p < 0.001) and stride length (p < 0.001) in single-task gait, as well as greater dual-task cost (DTC) for speed (p = 0.007), stride length (p = 0.014) and cadence (p = 0.029). Based on the DTC measures in HC, PD patients were further divided into two subgroups with normal DTC (PD-nDTC) and abnormally increased DTC (PD-iDTC). For PD-nDTC, voxel-based morphometric correlation analysis revealed a positive correlation between a cluster in the left primary motor cortex and stride-length DTC (r = 0.57, p = 0.027). For PD-iDTC, a negative correlation was found between a cluster in the right lingual gyrus and the DTC for gait cadence (r=-0.35, pFWE = 0.018). No significant correlations were found in HC. The associations found between brain morphometry and gait performance with a concurrent cognitive task may represent the substrate for gait and cognitive impairment occurring since the early stages of PD.

Cortical and subcortical morphometric changes and their relation to cognitive impairment in isolated REM sleep behavior disorder.

OBJECTIVE: To date, very few studies have focused on structural changes and their association with cognitive performance in isolated REM sleep behaviour disorder (iRBD). Moreover, the results of these studies are inconclusive. This study aims to evaluate differences in the associations between brain morphology and cognitive tests in iRBD and healthy controls. METHODS: Sixty-three patients with iRBD and thirty-six controls underwent MRI with a 3 T scanner. The cognitive performance was assessed by a comprehensive neuropsychological battery. Based on performance, the iRBD group was divided into two subgroups with (iRBD-MCI) and without mild cognitive impairment (iRBD-NC). The high-resolution T1-weighted images were analysed using an automated atlas segmentation tool, voxel-based (VBM) and deformation-based (DBM) morphometry to identify between-group differences and correlations with cognitive performance. RESULTS: VBM, DBM and the comparison of ROI volumes yielded no significant differences between iRBD and controls. In the iRBD group, significant correlations in VBM were found between several cortical and subcortical structures primarily located in the temporal, parietal, occipital lobe, cerebellum, and basal ganglia and three cognitive tests assessing psychomotor speed and one memory test. Between-group analysis of cognition revealed a significant difference between iRBD-MCI and iRBD-NC in tests including a processing speed component. CONCLUSIONS: iRBD shows deficits in several cognitive tests that correlate with morphological changes, the most prominent of which is in psychomotor speed and visual attention as measured by the TMT-A and associated with the volume of striatum, insula, cerebellum, temporal lobe, pallidum and amygdala.

Characterization of memory profile in idiopathic REM sleep behavior disorder.

OBJECTIVE: The present study aims to examine whether declarative memory dysfunction relates to impaired core memory mechanisms or attentional and executive dysfunction in idiopathic REM Sleep Behavior Disorder (iRBD). METHOD: In this observational, cross-sectional study, were enrolled 82 individuals with the diagnosis of iRBD according to the International Classification of Sleep Disorders and 49-matched healthy controls fulfilling inclusion criteria. All participants underwent two memory tasks, namely the Rey Auditory Verbal Learning Test (RAVLT) and Memory Binding Test (MBT), which include conditions of varying degrees of dependence on executive functioning, as well as different indicators of core memory processes (e.g., learning, retention, relational binding). RESULTS: We used Bayesian multivariate generalized linear model analysis to evaluate the effect of iRBD on memory performance controlled for effects of age and sex. Individuals with iRBD displayed worse memory performance in the delayed free recall task (b = -0.37, 95% PPI [-0.69, -0.05]), but not on delayed recognition of the same material. Their performance in cued recall tasks both in immediate and delayed conditions was in comparison to controls relatively spared. Moreover, the deficit in delayed free recall was mediated by attention/processing speed. CONCLUSIONS: In iRBD, we replicated findings of reduced free recall based on inefficient retrieval (retrieval deficit), which was small in terms of effect size. Importantly, the memory profile across measures does not support the presence of core memory dysfunction, such as poor learning, retention or associative binding.

The Instrumental Activities of Daily Living in Parkinson's Disease Patients Treated by Subthalamic Deep Brain Stimulation.

Background: Everyday functioning and instrumental activities of daily living (IADL) play a vital role in preserving the quality of life in patients with Parkinson's disease (PD) after deep brain stimulation of the subthalamic nucleus (STN-DBS). Objective: The main goal of the current study was to examine IADL change in pre-and post-surgery of the STN-DBS. We also analyzed the influence of the levodopa equivalent daily dose (LEDD) and global cognitive performance (Dementia Rating Scale; DRS-2) as covariates in relation to IADL. Methods: Thirty-two non-demented PD patients were administered before and after STN-DBS neurosurgery the Penn Parkinson's Daily Activities Questionnaire (PDAQ; self-report), the DRS-2 and Beck Depression Inventory (BDI-II) to assess IADL change, global cognition, and depression. Results: We found a positive effect of STN-DBS on IADL in the post-surgery phase. Moreover, lower global cognition and lower LEDD are predictive of lower IADL in both pre-surgery and post-surgery examinations. Summary/Conclusion: STN-DBS in PD is a safe method for improvement of everyday functioning and IADL. In the post-surgery phase, we show a relation of IADL to the severity of cognitive impairment in PD and to LEDD.

The normative data study of the Czech MATRICS consensus cognitive battery.

OBJECTIVE: The MATRICS consensus cognitive battery (MCCB) is a widely used neuropsychological battery for the assessment of cognitive dysfunction in schizophrenia. However, the accuracy of measurement is dependent on suitable normative data which are in the Czech Republic lacking. METHOD: The Czech academic research translation of the MCCB battery was administered to a sample of healthy volunteers aged 17 to 62 years (N = 573) and the effects of age, education and sex were examined. In addition, a comparison was made to examine the differences between the US and current normative data. RESULTS: Consistent with previous studies, significant effects of age, sex and education were found, however, in sex and education in distinct MCCB-domains. By comparing the original and current normative data, significant differences with small to large effect sizes were revealed in all domains except for Verbal Learning. CONCLUSIONS: We present nationally specific MCCB regression-based and tabular normative data applicable in research and clinical settings.

Brief Visuospatial Memory Test-Revised: normative data and clinical utility of learning indices in Parkinson's disease.

Introduction: The Brief Visual Memory Test-Revised (BVMT-R) is a frequently used visuospatial declarative memory test, but normative data in the Czech population are lacking. Moreover, the BVMT-R includes promising learning indexes that can be used to detect learning deficits in Parkinson's disease (PD). However, its clinical usefulness has not yet been thoroughly examined. Early detection of memory impairment in PD is essential for effective treatment. Therefore, this study aimed to provide BVMT-R Czech normative data for clinical use and to find the detection potential of the principal BVMT-R scores, including new learning indices, to capture the cognitive deficit in PD. Method: The BVMT-R were administered to a normative sample of 920 participants aged 17 to 95 years and to a clinical sample of 60 PD patients; 25 with mild cognitive impairment (PD-MCI) and 35 with normal cognition (PD-NC). In order to provide normative values, multiple regression analyses were employed, and to compare the clinical and control sample, Bayesian Hierarchical Linear Models were used. Results: The best model for regression-based norms showed to be with age + age2 + education + sex as predictors. From all learning indexes, L6 (sum of trials 1-3), followed by, L4 (sum of trials 1-3 multiplied by the difference between the highest and the lowest score) best differentiated between controls or PD-NC and PD-MCI. Conclusions: We provide regression-based normative values for BVMT-R that could be used in clinical settings and meta-analytic efforts. Furthermore, we revealed visuospatial learning and memory deficit in PD-MCI. We have also identified the most discriminative learning index adapted to BVMT-R.

Profile of cognitive deficits in schizophrenia and factor structure of the Czech MATRICS Consensus Cognitive Battery.

We aimed to validate the Czech version of the MATRICS Consensus Cognitive Battery (MCCB). The MCCB is a test battery designed to assess cognitive treatment effects in clinical trials of patients with schizophrenia. The valid, reliable and replicable measurement of cognition in schizophrenia is of substantial importance for such clinical trial studies. We performed a psychometric analysis of the MCCB composite and domain scores based on ROC analysis of 67 schizophrenia patients and 67 age- and education-matched healthy controls from a total sample of 220 controls. Also, we correlated MCCB variables with scales measuring psychosocial functioning (Personal and Social Performance scale; PSP). The internal consistency of all 10 tests in the MCCB battery was good (Cronbach's α = 0.85 (95% CI [0.83, 0.88])). The discriminative validity for the detection of neurocognitive dysfunction in schizophrenia based on the area under the curve of MCCB composite T-score was ≥90% (95% CI [0.85, 0.96]) and all MCCB domains showed ps < .001. The MCCB global composite and the Speed of Processing domain score significantly predicted the PSP ratings. A confirmatory factor analysis on the whole control sample (N = 220) showed an optimal fit for a 6-factor in comparison to 1-factor solution. In conclusion, we found high discriminative validity for the Czech MCCB version, similar to the differentiation of schizophrenia versus healthy control groups in the original MCCB studies. We also established the factorial validity of the MCCB and showed that the overall composite of the MCCB predicts psychosocial functioning in the patient group.