Do parkinsonian patients have trouble telling lies? The neurobiological basis of deceptive behaviour

Parkinson's disease is a common neurodegenerative disorder with both motor symptoms and cognitive deficits such as executive dysfunction. Over the past 100 years, a growing body of literature has suggested that patients with Parkinson's disease have characteristic personality traits such as industriousness, seriousness and inflexibility. They have also been described as ‘honest’, indicating that they have a tendency not to deceive others. However, these personality traits may actually be associated with dysfunction of specific brain regions affected by the disease. In the present study, we show that patients with Parkinson's disease are indeed ‘honest’, and that this personality trait might be derived from dysfunction of the prefrontal cortex. Using a novel cognitive task, we confirmed that patients with Parkinson's disease (n = 32) had difficulty making deceptive responses relative to healthy controls (n = 20). Also, using resting-state 18F-fluorodeoxyglucose PET, we showed that this difficulty was significantly correlated with prefrontal hypometabolism. Our results are the first to demonstrate that the ostensible honesty found in patients with Parkinson's disease has a neurobiological basis, and they provide direct neuropsychological evidence of the brain mechanisms crucial for human deceptive behaviour

Autobiographical memory in Parkinson's disease: A retrieval deficit

yesThis study examined the effects of providing cues to facilitate autobiographical memory retrieval in Parkinson's disease. Previous findings have shown that individuals with Parkinson's disease retrieve fewer specific autobiographical memories than older adult controls. These findings are clinically significant since the quality of autobiographical memory is linked to identity and sense of self. In the current study, 16 older adults with Parkinson's disease without dementia and 16 matched older adult controls were given 3 min in which to recall autobiographical memories associated with five different time periods and to give each memory a short title. Participants were later asked to retrieve the memories in three phases: firstly in a free recall phase; secondly in response to general cues (time periods) and finally in response to specific cues (the short titles previously given). The number of memories and the quality of the memory (general or specific) was recorded in each condition. Compared with matched older adult controls, the Parkinson's disease group was impaired in retrieving the memories that they had previously given in the free recall phase and in response to general cues. The performance of the group with Parkinson's disease was only equivalent to the older adults when they retrieved memories in response to self-generated cues. The findings are discussed in relation to theories of autobiographical memory and the neuropsychology of Parkinson's disease

Apathy in Mild Parkinson's Disease: Neuropsychological and Neuroimaging Evidence.

BACKGROUND: Apathy is one of the most common neuropsychiatric symptoms in Parkinson's disease (PD). Few studies have investigated the cognitive and neuroanatomical correlates of apathy in PD, and those which have done so have not controlled for the presence of other neuropsychiatric comorbidities. OBJECTIVE: To explore the cognitive and neuroanatomical correlates of apathy in PD at a mild disease stage. METHODS: Sixty-five PD patients and 24 healthy controls participated in this study. Patients underwent extensive neuropsychological screening, neuropsychiatric assessment using the Neuropsychiatric Inventory, structural MRI scanning, and neurological examination. A voxel-based multiple regression analysis was used to assess the relationship between grey matter volumes and apathy scores. RESULTS: Higher apathy scores correlated with lower grey matter volume in several brain areas including the left insula, left inferior/middle/medial frontal gyrus, right anterior cingulate, and the left superior temporal gyrus. Significant impairments were found in tests assessing executive functions, and a trend-level significant difference was observed in long term memory tests in patients with apathy, when compared with patients without apathy. CONCLUSIONS: Apathy was associated with greater levels of atrophy in the frontal and temporal cortex, and anterior cingulate, as well as overall lower level of cognitive performance, particularly in executive function and memory skills. Apathy appears to be associated with cognitive impairments in PD, therefore, treatment of this symptom might mitigate its effects on cognitive performance in this clinical population

Distinguishing Parkinson's disease from atypical parkinsonian syndromes using PET data and a computer system based on support vector machines and Bayesian networks

Differentiating between Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) is still a challenge, specially at early stages when the patients show similar symptoms. During last years, several computer systems have been proposed in order to improve the diagnosis of PD, but their accuracy is still limited. In this work we demonstrate a full automatic computer system to assist the diagnosis of PD using 18F-DMFP PET data. First, a few regions of interest are selected by means of a two-sample t-test. The accuracy of the selected regions to separate PD from APS patients is then computed using a support vector machine classifier. The accuracy values are finally used to train a Bayesian network that can be used to predict the class of new unseen data. This methodology was evaluated using a database with 87 neuroimages, achieving accuracy rates over 78%. A fair comparison with other similar approaches is also provided.This work is part of a project approved by the Andalucía Talent Hub Program launched by the Andalusian Knowledge Agency, co-funded by the European Union's Seventh Framework Program, Marie Sklodowska-Curie actions (COFUND Grant Agreement no 291780) and the Ministry of Economy, Innovation, Science and Employment of the Junta de Andalucía. The work was also supported by the University of Granada (Spain), the University for Munich (Germany), the MICINN (Spain) under the TEC2012–34306 project and the Consejera de Innovacin, Ciencia y Empresa (Junta de Andaluca, Spain) under the P11–TIC–7103 excellence project

Apathy, but Not Depression, Reflects Inefficient Cognitive Strategies in Parkinson's Disease

The relationship between apathy, depression and cognitive impairment in Parkinson's disease (PD) is still controversial. The objective of this study is to investigate whether apathy and depression are associated with inefficient cognitive strategies in PD.In this prospective clinical cohort study conducted in a university-based clinical and research movement disorders center we studied 48 PD patients. Based on clinical evaluation, they were classified in two groups: PD with apathy (PD-A group, n = 23) and PD without apathy (PD-NA group, n = 25). Patients received clinical and neuropsychological evaluations. The clinical evaluation included: Apathy Evaluation Scale-patient version, Hamilton Depression Rating Scale-17 items, the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr staging system; the neuropsychological evaluation explored speed information processing, attention, working memory, executive function, learning abilities and memory, which included several measures of recall (immediate free, short delay free, long delay free and cued, and total recall).PD-A and PD-NA groups did not differ in age, disease duration, treatment, and motor condition, but differed in recall (p<0.001) and executive tasks (p<0.001). Immediate free recall had the highest predictive value for apathy (F = 10.94; p = 0.002). Depression and apathy had a weak correlation (Pearson index= 0.3; p<0.07), with three items of the depression scale correlating with apathy (Pearson index between .3 and.4; p<0.04). The depressed and non-depressed PD patients within the non-apathetic group did not differ.Apathy, but not depression, is associated with deficit in implementing efficient cognitive strategies. As the implementation of efficient strategies relies on the fronto-striatal circuit, we conclude that apathy, unlike depression, is an early expression of executive impairment in PD

Long-term effects of STN DBS on mood: psychosocial profiles remain stable in a 3-year follow-up

<p>Abstract</p> <p>Background</p> <p>Deep brain stimulation of the subthalamic nucleus significantly improves motor function in patients with severe Parkinson's disease. However, the effects on nonmotor aspects remain uncertain. The present study investigated the effects of subthalamic nucleus deep brain stimulation on mood and psychosocial functions in 33 patients with advanced Parkinson's disease in a three year follow-up.</p> <p>Methods</p> <p>Self-rating questionnaires were administered to 33 patients prior to surgery as well as three, six, twelve and 36 months after surgery.</p> <p>Results</p> <p>In the long run, motor function significantly improved after surgery. Mood and psychosocial functions transiently improved at one year but returned to baseline at 36 months after surgery. In addition, we performed cluster and discriminant function analyses and revealed four distinct psychosocial profiles, which remained relatively stable in the course of time. Two profiles featured impaired psychosocial functioning while the other two of them were characterized by greater psychosocial stability.</p> <p>Conclusion</p> <p>Compared to baseline no worsening in mood and psychosocial functions was found three years after electrode implantation. Moreover, patients can be assigned to four distinct psychosocial profiles that are relatively stable in the time course. Since these subtypes already exist preoperatively the extent of psychosocial support can be anticipatory adjusted to the patients' needs in order to enhance coping strategies and compliance. This would allow early detection and even prevention of potential psychiatric adverse events after surgery. Given adequate psychosocial support, these findings imply that patients with mild psychiatric disturbances should not be excluded from surgery.</p

Apathy is associated with executive functioning in first episode psychosis

<p>Abstract</p> <p>Background</p> <p>The underlying nature of negative symptoms in psychosis is poorly understood. Investigation of the relationship between the different negative subsymptoms and neurocognition is one approach to understand more of the underlying nature. Apathy, one of the subsymptoms, is also a common symptom in other brain disorders. Its association with neurocognition, in particular executive functioning, is well documented in other brain disorders, but only studied in one former study of chronic patients with schizophrenia. This study investigates the association between apathy and neurocognitive functioning in patients with first episode psychosis (FEP), with the hypothesis that apathy is more associated with tests representing executive function than tests representing other neurocognitive domains.</p> <p>Methods</p> <p>Seventy-one FEP patients were assessed with an extensive neuropsychological test battery. Level of apathy was assessed with the abridged Apathy Evaluation Scale (AES-C-Apathy).</p> <p>Results</p> <p>AES-C-Apathy was only significantly associated with tests from the executive domain [Semantic fluency (r = .37, p < .01), Phonetic fluency (r = .25, p < .05)] and working memory [Letter Number Span (r = .26; p =< .05)]; the first two representing the initiation part of executive function. Confounding variables such as co-occuring depression, positive symptoms or use of antipsychotic medication did not significantly influence the results.</p> <p>Conclusion</p> <p>We replicated in FEP patients the relationship between apathy and executive functioning reported in another study for chronic patients with schizophrenia. We also found apathy in FEP to have the same relationship to executive functioning, as assessed with the Verbal fluency tests, as that reported in patients with other brain disorders, pointing to a common underlying nature of this symptom across disorders.</p

Cognitive and neuroanatomical correlates of neuropsychiatric symptoms in Parkinson's disease: A systematic review

Introduction Neuropsychiatric symptoms are one of the most common non-motor symptoms in Parkinson's disease (PD). These symptoms have a negative impact on daily living activities and cognitive abilities. This review will be centred on published articles which focused on clarifying the cognitive and neuroanatomical features associated with the appearance of specific neuropsychiatric symptoms in this disease. Methods All articles indexed in the Web of Science and PubMed databases were reviewed for potential inclusion in October 2014. In the first stage of the review, we identified 41 articles that investigated neuropsychiatric symptoms and cognitive impairments in PD. In the second stage, there were 26 published articles on the neural bases of neuropsychiatric symptoms in PD. Results The main findings revealed that executive dysfunctions were common in patients with depression, apathy, visual hallucinations (VH), impulse control disorders (ICDs) and anxiety, whereas, memory deficits were associated mainly with depression and VH. Imaging studies have shown that frontal lobe atrophy was frequently observed in patients with depression, apathy, VH and ICDs. Conclusion This review gives a snapshot of those cognitive and neural correlates of neuropsychiatric symptoms in PD. Methodological shortcoming in the available studies were identified, however, of which the most critical appeared neglecting the presence of multiple neuropsychiatric symptoms in some of the patients included in studies of specific individual symptoms. Additionally, in most studies only patients in the moderate to severe stages were included which limits possible inferences to the early stage of the disease

Visual problems associated with traumatic brain injury:Vision with traumatic brain injury

Traumatic brain injury (TBI) and its associated concussion are major causes of disability and death. All ages can be affected but children, young adults and the elderly are particularly susceptible. A decline in mortality has resulted in many more individuals living with a disability caused by TBI including those affecting vision. This review describes: (1) the major clinical and pathological features of TBI; (2) the visual signs and symptoms associated with the disorder; and (3) discusses the assessment of quality of life and visual rehabilitation of the patient. Defects in primary vision such as visual acuity and visual fields, eye movement including vergence, saccadic and smooth pursuit movements, and in more complex aspects of vision involving visual perception, motion vision (‘akinopsia’), and visuo-spatial function have all been reported in TBI. Eye movement dysfunction may be an early sign of TBI. Hence, TBI can result in a variety of visual problems, many patients exhibiting multiple visual defects in combination with a decline in overall health. Patients with chronic dysfunction following TBI may require occupational, vestibular, cognitive and other forms of physical therapy. Such patients may also benefit from visual rehabilitation, including reading-related oculomotor training and the prescribing of spectacles with a variety of tints and prism combinations