Impact of Cognitive Profile on Impulse Control Disorders Presence and Severity in Parkinson's Disease

Background: Impulse control disorders (ICDs) and related behaviors are frequent in Parkinson's disease (PD). Mild cognitive impairment (PD-MCI) and dementia (PDD), both characterized by heterogeneous cognitive phenotypes, are also commonly reported in PD. However, the frequency and severity of ICD within PD cognitive states is unknown.Methods: Three hundred and twenty-six PD patients completed a comprehensive neuropsychological assessment and were classified as PD-MCI, PDD, or without cognitive alterations (PD-NC). The Minnesota impulsive disorders interview was used to ascertain the presence (ICD+) or absence (ICD–) of ICD. The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale was used to assess ICD severity. A subsample of 286 patients evaluated with the same cognitive tasks was selected in order to investigate the characteristics of ICD in PD cognitive phenotypes.Results: ICDs were present in 55% of PD-NC, in 50% of PD-MCI, and in 42% of PDD patients. Frequencies of ICD+ with attentive (ICD+: 20% vs. ICD–: 4%; p = 0.031) and executive impairments (ICD+: 44% vs. ICD–: 30%; p = 0.027) were higher in the PD-MCI and PDD subgroups, respectively. As expected, no differences were observed in the PD-NC. PD-MCI with attentive impairments presented higher percentage of ICD+ with deficits in the Trail Making Test B-A but not in the Digit Span Sequencing task. In PDD, executive failures concerned Similarities task (ICD+: 67%; ICD–: 29%; p = 0.035), with no differences between ICD+ and ICD– in the Stroop task.Conclusions: Prevalence and severity of ICDs and related behaviors do not differ in PD with different cognitive states. However, ICD+ are more likely to show deficits, respectively in attentive and in executive domains, specifically in the Trail Making Test B-A task for the attention and working memory domain in PD-MCI and in the Similarities task for the executive function domain in PDD. Prospective studies should evaluate if these tests can be used as screening tool for ICDs in PD

Erratum to "Double-blind Randomized Trial of tDCS Versus Sham in Parkinson Patients With Mild Cognitive Impairment Receiving Cognitive Training" Brain Stimulation 8 (2015) 1223-1225.

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Action Selection and Motor Decision Making: Insights from Transcranial Magnetic Stimulation

In everyday life, goal-oriented motor behaviour relies on the estimation of the rewards/costs associated with alternative actions and on the appropriate selection of movements. Motor decision making is defined as the process by which a motor plan is chosen among a set of competing actions based on the expected value. In the present literature review we discuss evidence from transcranial magnetic stimulation (TMS) studies of motor control. We focus primarily on studies of action selection for instructed movements and motor decision making. In the first section, we delve into the usefulness of various TMS paradigms to characterise the contribution of motor areas and distributed brain networks to cued action selection. Then, we address the influence of motivational information (e.g., reward and biomechanical cost) in guiding action choices based on TMS findings. Finally, we conclude that TMS represents a powerful tool for elucidating the neurophysiological mechanisms underlying action choices in humans

Effect of Intensive Rehabilitation Program in Thermal Water on a Group of People with Parkinson’s Disease: A Retrospective Longitudinal Study

: The main objective of this study is to test the effect of thermal aquatic exercise on motor symptoms and quality of life in people with Parkinson's Disease (PD). Fourteen participants with diagnosis of idiopathic PD completed the whole rehabilitation session and evaluation protocol (Hoehn and Yahr in OFF state: 2-3; Mini Mental State Examination >24; stable pharmacological treatment in the 3 months prior participating in the study). Cognitive and motor status, functional abilities and quality of life were assessed at baseline and after an intensive rehabilitation program in thermal water (12 sessions of 45 min in a 1.4 m depth pool at 32-36 ∘C). The Mini Balance Evaluation System Test (Mini-BESTest) and the PD Quality of Life Questionnaire (PDQ-39) were considered as main outcomes. Secondary assessment measures evaluated motor symptoms and quality of life and psychological well-being. Participants kept good cognitive and functional status after treatment. Balance of all the participants significantly improved (Mini-BESTest: p<0.01). The PDQ-39 significantly improved after rehabilitation (p=0.038), with significance being driven by dimensions strongly related to motor status. Thermal aquatic exercise may represent a promising rehabilitation tool to prevent the impact of motor symptoms on daily-life activities of people with PD. PDQ-39 improvement foreshows good effects of the intervention on quality of life and psychological well-being

Lexical-semantic parameters as robust endophenotypes of abnormal cognitive decline in ageing

The objective of this dissertation was to characterise the relative contribution of genetic influences to individual differences in cross sectional performance and decline of semantic-lexical abilities and to investigate whether these linguistic effects indicating semantic degradation are sensitive indicators of medial temporal atrophy in early Alzheimer's disease and in patients with mild cognitive impairment of amnestic type (aMCI). The effect of ApoE status in the genetic profile of these groups on deterioration of semantic abilities was studied to verify whether there was any relationship between variation in lexical factors and genetic variability. Oral generation of words belonging to two categories (animal and fruits) during a fluency tasks was required. In AD patients there was an effect of genotype but, although strong, this was diluted by the advanced cognitive deterioration and could only be seen as a tendency to be stronger in ε4 carriers. The words produced by the aMCI carriers were significantly earlier acquired than those of non-carriers and controls. These behavioural findings confirmed evidence from other recent studies and showed that a significant proportion of phenotype variability in performance on fluency tasks was influenced by genetic factors. Impairments in semantic tasks in the ε4 allele carrier population might indicate either that individuals who will develop AD never fully develop semantic skills, or that the neuroanatomical substrate of semantic abilities is selective sensitive to the earliest effects of the AD neuropathology. On the basis of this result it seemed reasonable to hypothesise that the presence of the “semantic endophenotype” in people carriyng the ApoE vulnerability mutation might be associated with atrophy in areas early affected by neuropathology due to AD and involved in semantic memory retrieval. Using lexical semantic competency in aMCI carriers as an endophenotype, grey matter volume loss in aMCI ε4 carriers/non-carriers and in controls was compared and the residual volume correlated with allele burden and with age of acquisition values for words produced in a category fluency task. Direct group comparisons showed that carriers had grey matter volume loss which was generally confined to limbic regions and medial temporal structures, and non-carriers had greater atrophy in temporal and parieto-occipital neocortex. aMCI subjects had significantly impoverished lexical semantic output compared to controls, more marked in aMCI carriers. A voxel based correlation analysis showed that greater volume loss in parahippocampal gyrus and thalamus was associated with a tendency to retrieve earlier acquired words in the category fluency task. The results suggest a relatively specific impact of ApoE 4 burden and underline the value of linguistic assessment in preclinical diagnosis. The detrimental role of this mutation found in aMCI individuals was also assessed at the larger stage in the disease process by direct comparisons in minimal to mild AD ε4 carriers/non-carrier patients. VBM comparison analysis confirmed the observation done in the genetically determined aMCI subgroups. AD ε4- carriers showed greater atrophy in mediotemporal structures compared to non-carriers whose grey matter volume loss was more widespread in more neocortical areas. Finally, an age, gender and education based norms for AoA, Typicality and Familiarity was built up in order to create a valid psychometric instrument able to detect and monitor subtle semantic deficits in ApoE ε4 carriers over time