Frontal deficits differentiate progressive supranuclear palsy from Parkinson's disease

The clinical differentiation of progressive supranuclear palsy from Parkinson's disease can be challenging, due to overlapping clinical features and a lack of diagnostic markers. Abnormalities in cognitive function form part of the clinical spectrums of these diseases and distinctive cognitive profiles may be helpful in differentiating these diseases in the diagnostic period. A comprehensive neuropsychological test battery was administered to 12 patients with clinically diagnosed progressive supranuclear palsy and 12 patients with Parkinson's disease matched for age and disease duration. Effect size (Cohen's d) was calculated for cognitive tests that were significantly different between groups. Patients with progressive supranuclear palsy performed significantly worse than those with Parkinson's disease on measures of processing speed, verbal fluency, planning, verbal abstract reasoning, verbal memory, and made more perseverative responses on a set shifting task. Measures of executive function, manual dexterity and processing speed were most diagnostically useful (Cohen's d > 2.0) in differentiating between progressive supranuclear palsy and Parkinson's disease. These findings suggest that more severe and prominent ‘frontal’ cognitive deficits in patients with progressive parkinsonism would be helpful in predicting progressive supranuclear palsy rather than Parkinson's disease and these findings may contribute to the development of diagnostic criteria.     

Relationships between movement initiation times and movement-related cortical potentials in Parkinson's disease

Movement-related cortical potentials recorded from the scalp reveal increasing cortical activity occurring prior to voluntary movement. Studies of set-related cortical activity recorded from single neurones within premotor and supplementary motor areas in monkeys suggest that such premovement activity may act to prime activity of appropriate motor units in readiness to move, thereby facilitating the movement response. Such a role of early stage premovement activity in movement-related cortical potentials was investigated by examining the relationship between premovement cortical activity and movement initiation or reaction times. Parkinson's disease and control subjects performed a simple button-pressing reaction time task and individual movement-related potentials were averaged for responses with short compared with long reaction times. For Parkinson's disease subjects but not for the control subjects, early stage premovement cortical activity was significantly increased in amplitude for faster reaction times, indicating that there is indeed a relationship between premovement cortical activity amplitude and movement initiation or reaction times. In support of studies of set-related cortical activity in monkeys, it is therefore suggested that early stage premovement activity reflects the priming of appropriate motor units of primary motor cortex, thereby reducing movement initiation or reaction times.PsycINFO classification: 2330; 2520; 2530     

Interference Effects from Observed Movement in Parkinson's Disease

Previous research has demonstrated that Parkinson's disease patients have an increased susceptibility to response conflict. In the present study, the authors investigate whether Parkinson's patients have a similar sensitivity to interference from observed movements. In all, 10 patients and 10 controls performed horizontal and vertical arm movements while watching a video of either a person performing similar movements or a moving dot. Movements were performed in the same plane (congruent) and orthogonal to the observed movement (incongruent). The off-axis variance of movements was our index of interference. Although patients tended to exhibit more off-axis variability than did controls, both groups demonstrated similar congruence effects, with greater variance in incongruent conditions. These results indicated that increased susceptibility to interference in Parkinson's disease does not extend to interference from observed movements.     

Corrigendum

Mild to moderate Parkinson's disease shows more denervation in the posterodorsal striatum and sparing of the anteroventral striatum. Dopaminergic medications can interfere with anteroventral striatum function by overdosing this relatively intact structure. The authors determined how regional striatal denervation affects medication-associated sequence learning impairment in Parkinson's disease. Eighteen Parkinson's patients performed motor sequence learning on and off levodopa. Patients underwent ¹¹C-dihydrotetrabenazine positron emission tomography scans to measure nigrostriatal denervation. Patients with more preserved putamen were more likely to exhibit levodopa-associated sequence learning impairments. Furthermore, the ratio of denervation in the anterior to posterior dorsal putamen predicted the level of learning differences on and off levodopa. These results demonstrate that the spatial pattern of nigrostriatal dopaminergic denervation predicts medication responsiveness for motor sequence learning.     

The Role of Recollection and Familiarity in Nondemented Parkinson's Patients

The aim of the current study was to examine if recollection and familiarity decline in nondemented Parkinson's patients. To do so we compared a sample of older people with Parkinson's disease (n = 32) to a control sample of healthy older people (n = 32) on an associative recognition task in which we manipulated the repetition of the pairs during the study phase (half of the pairs were presented once and half twice) to obtain corrected estimates of recollection, familiarity, and false recognition based on the logic of the process-dissociation procedure. The results clearly show that recollection is impaired but familiarity is preserved in nondemented Parkinson's patients. The results show that memory for pairs in Parkinson's patients relies largely on the familiarity of each item and not on a precise recollection of associative information, supporting the idea that recollection-based monitoring processes are impaired in these patients.     

Effect of click trains on duration estimates by people with Parkinson's disease

Patients with a diagnosis of Parkinson's disease and age- and IQ-matched controls estimated the duration of short 500-Hz tones (325–1,225 ms), on trials where the tone was either preceded by 3 s of 5-Hz clicks, or presented without clicks. The click manipulation had been shown in earlier studies with student participants to make verbal estimates longer. Patients were tested both on and off their dopaminergic medication, and controls were also tested in two sessions. Verbal estimates were markedly and significantly longer on trials with clicks than on those without clicks for both the patients and the controls, but there were no significant performance differences between patients or controls, nor between the on and off medication sessions in the patients. The study shows that a manipulation of subjective time, which has had small but consistent effects in student participants, also affects timing in patients and adds to a growing body of evidence that timing in patients with Parkinson's disease may in many cases have the same characteristics as those of neurologically intact control groups.     

Processing of proprioceptive information in Parkinson's disease patients

The present study is concerned with a comparison of Parkinson's disease patients and normal subjects on a number of simple and choice reaction time tasks in accordance with Sternberg's interactive procedures. The results indicated that the motor disorder in Parkinson's disease was at the level of output processing and related to the inability of central mechanisms to select and organize responses. Further, the results suggested that patients had difficulty in formulating complex plans or programmes for action.     

Eye-Hand Coordination in Aging and in Parkinson’s Disease

Aiming movements to defined target positions were performed as fast and as accurately as possible by younger and older subjects and by patients in the early stages of Parkinson's disease (PD). Movement time and accuracy were tested in two conditions: with and without a centre cue. Older subjects exhibited slower movement time relative to the younger subjects only when the centre cue was present suggesting inefficient feedback processing. The performance of patients with PD was found to be as precise as that of older subjects. The movements of PD subjects, however, were slower in both conditions. Finally, the performance of subjects improved over trials. The data suggest that there is no difference in the nature of the control processes used by older and early-stage PD subjects, but that there is a reduction in the speed of these processes in PD.     

De l’efficacité d’un « exergame » sur le stress perçu et le sentiment d’auto-efficacité chez un patient atteint de la maladie de Parkinson : résultats d’un protocole à cas unique de type ABAB

IntroductionRehabilitation is of paramount importance in Parkinson's disease because it compensates for deficiencies in the body's structures and functions and preserves relative autonomy for as long as possible. Nevertheless, people with this disease report low adherence to physical activity.ObjectiveThe purpose of this research is to examine the potential psychological benefits of using an “exergame”, a “serious game” based on physical exercise in the functional rehabilitation of Parkinson's disease, including stress and self-efficacy.MethodA single case ABAB protocol (n = 1) over 4 weeks, 1 week per phase, 3 observation points per phase, was developed. Our variables were measured by questionnaires and we used visual and statistical analysis to interpret changes in scores between Phases A and B.OutcomesThe “exergame” intervention appears to improve perceived stress and self-efficacy. The results are accompanied by an exploratory interview, reporting qualitative changes.ConclusionThe use of “exergame” in Parkinson's disease seems promising, and does not harm the person. But the methodology used is not sufficient to conclude on its real effectiveness. Further studies are needed.     

Pictorial and lexical priming: Patterns of implicit memory in Alzheimer's and Parkinson's disease patients

Lexical and pictorial priming were examined in patients with Alzheimer's disease and in demented and nondemented patients with Parkinson's disease. Control subjects were divided into young and elderly. Lexical priming used a word‐stem completion task. Pictorial priming task was based on Rey's superimposed pictures test. Elderly normal subjects demonstrated lower lexical priming scores than those of young subjects. Analysis of covariance with age and educational level as covariates showed that normal controls, demented and nondemented Parkinsonian patients, and Alzheimer patients did not differ significantly on the lexical priming task. Pictorial priming scores did not differ significantly between elderly and younger controls. In contrast there was a striking impairment of pictorial priming in Parkinsonian patients, both demented and nondemented. Performance of subjects with mild Alzheimer's disease was superior to that of nondemented Parkinsonian patients. Our results suggest that performance in lexical priming task diminishes with physiological ageing but is unaffected by mild or moderate Alzheimer's disease. Our study also observes the existence of a selective pictorial priming deficit in Parkinson's disease; however, this deficit is not specific, as it is also observed to a lesser degree in Alzheimer's disease. It may therefore be concluded that the systems serving pictorial priming are both cortical and subcortical.     

A Comparison of Effectiveness of Dohsa‐hou and the Alexander Technique on Happiness,Social Adjustment,Hope, Mental Health,and Quality of Life in Patients with Parkinson's Disease

The purpose of this study was to compare the effectiveness of Dohsa‐hou and the Alexander Technique on happiness, social adjustment, hope, mental health, and quality of life in patients with Parkinson's disease. The statistical population of this study included all of the patients with Parkinson's disease who were clients of neural therapeutic centers in Isfahan City in 2015. Among this population, 28 patients were selected through convenience sampling as the sample of the study. The Oxford Happiness Questionnaire, the Social Adjustment Scale, the Adult Hope Scale, the General Health Questionnaire, and the Word Health Quality of Life Questionnaire were used as the instruments of the study. Data were analyzed by analyses of variance with repeated measures. The results showed that both interventions of this study can improve happiness, hope, and quality of life in patients with Parkinson's disease, but Dohsa‐hou is more effective than the Alexander Technique in the improvement of happiness and hope. Probable explanations have been discussed.     

Does Response Inhibition Have Pre- and Postdiagnostic Utility in Parkinson's Disease?

ABSTRACT. Parkinson's disease (Pd) is the second most prevalent degenerative neurological condition worldwide. Improving and sustaining quality of life is an important goal for Parkinson's patients. Key areas of focus to achieve this goal include earlier diagnosis and individualized treatment. In this review the authors discuss impulse control in Pd and examine how measures of impulse control from a response inhibition task may provide clinically useful information (a) within an objective test battery to aid earlier diagnosis of Pd and (b) in postdiagnostic Pd, to better identify individuals at risk of developing impulse control disorders with dopaminergic medication.     

Semantic Fluency Performance of Patients with Cortical and Subcortical Neurodegenerative Diseases

Previous studies using the Animals Fluency Test have shown that dementia patients with Alzheimer's disease (AD), Huntington's disease (HD), or Parkinson's disease (PD) produce fewer correct words and have smaller semantic cluster sizes than controls or PD patients without dementia (PDND). Although the number of correct words generated by the patients with AD was positively correlated with mental status, cluster size, surprisingly, was not. To increase word output and increase the reliability of estimates of cluster size, semantic fluency was reexamined using the Supermarket Fluency Task. Overall, patients with HD or PD with dementia (PDD) exhibited reduced cluster sizes compared to older controls or PDND patients, but cluster sizes were only marginally reduced for patients with AD. These effects were evident only for female participants, because the cluster sizes for elderly control men were substantially smaller than those of elderly women. For the female patients with AD, cluster size was correlated with mental status, but the relationship was nonlinear. Cluster size was normal for mildly demented patients with AD, but much reduced for moderately or severely demented participants. In contrast to a previous report, in the present study the proportion of category labels generated was increased for patients with HD with dementia but not for patients with AD. This finding questions one line of evidence that semantic memory stores undergo “bottom-up” degradation in AD. Together with previous results, these findings indicate that semantic cluster size reflects efficiency of access to semantic knowledge which is similarly compromised in subcortical and cortical diseases.     

The effect of dopaminergic medication on conflict adaptation in Parkinson's disease

Parkinson's disease (PD) is a neurological disorder associated primarily with motor symptoms such as tremor, slowness of movement, and difficulties with gait and balance. Most patients take dopaminergic medication to improve their motor functions. Previous studies reported indications that such medication can impair higher cognitive functions (cf. dopamine overdose hypothesis). In the present study, we examined the effect of medication status on conflict adaptation. PD patients performed a Stroop task in which we manipulated the proportion of congruent and incongruent items, thereby allowing us to explore conflict adaptation. The use of mouse movements allowed us to examine the action dynamics of conflict adaptation in PD, and their sensitivity to dopaminergic medication. Each patient performed the same task twice: once without making changes to their regular medication regime, and once after overnight withdrawal from their medication. Results showed that medication improved mouse movements and alleviated motor symptoms. Moreover, patients' mouse movements were modulated as a function of the proportion congruency manipulation, revealing conflict adaptation in PD, which was unaffected by medication status. The present study extends earlier work on conflict adaptation in PD where reduced transient (trial-by-trial) conflict adaptation was observed ON compared to OFF medication (Duthoo et al., 2013, Neuropsychology, 27, 556). Our findings suggest that more sustained cognitive control processes may not be sensitive to dopamine overdose effects.     

Slow echo: facial EMG evidence for the delay of spontaneous,but not voluntary,emotional mimicry in children with autism spectrum disorders

Spontaneous mimicry, including that of emotional facial expressions, is important for socio‐emotional skills such as empathy and communication. Those skills are often impacted in autism spectrum disorders (ASD). Successful mimicry requires not only the activation of the response, but also its appropriate speed. Yet, previous studies examined ASD differences in only response magnitude. The current study investigated timing and magnitude of spontaneous and voluntary mimicry in ASD children and matched controls using facial electromyography (EMG). First, participants viewed and recognized happy, sad, fear, anger, disgust and neutral expressions presented at different durations. Later, participants voluntarily mimicked the expressions. There were no group differences on emotion recognition and amplitude of expression‐appropriate EMG activity. However, ASD participants’ spontaneous, but not voluntary, mimicry activity was delayed by about 160 ms. This delay occurred across different expressions and presentation durations. We relate these findings to the literature on mirroring and temporal dynamics of social interaction.     

Testing the dopamine overdose hypothesis in action control: A study in people with Parkinson's disease

Prior work on patients with Parkinson's disease (PD) has shown that the administration of dopaminergic medication in the early to intermediate stages of PD benefits (motor) functions associated with the dopamine-depleted dorsal striatal circuitry but may ‘overdose’ and interfere with (cognitive) functions associated with the relatively intact ventral striatal circuitry. The present study aimed to elucidate this so-called dopamine overdose hypothesis for the action control domain. Using a within-subject design in a sample of 13 people with PD, we evaluated the effect of dopaminergic medication on two cognitive processes underlying goal-directed behaviour, namely action selection and initiation through event binding and conflict adaptation. We also investigated whether individual differences in the magnitude of medication effects were associated across these processes. Results showed no indications that dopaminergic medication affects action selection and initiation or conflict adaptation in PD patients. Additionally, we observed no correlations between both cognitive processes nor between individual differences in medication effects. Our findings do not support the notion that dopaminergic medication modulates action control processes, suggesting that the dopamine overdose hypothesis may only apply to a specific set of cognitive processes and should potentially be refined.     

The Discriminating Properties of an Optoelectronic Movement Analysis Method in Patients With Parkinsonism

Several partly overlapping diseases have Parkinsonism as a symptom and tools that may differentiate between these disorders would be helpful. The authors evaluated the discriminating properties of the objective automated posturo-locomotor-manual (PLM) L-DOPA test in regard to health, and the movement disorders Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). A PLM test–retest procedure was performed in healthy controls (n = 37) and results were compared with PLM L-DOPA tests performed by 132 patients with Parkinsonism in intermediate to advanced stages (56 PD, 53 MSA, 23 PSP). The movement time (MT) for the standardized movement and its different components was measured. The discriminating abilities of individual, or combinations of, test variables were determined by forward stepwise multiple logistic regression and evaluated with receiver-operating characteristic (ROC) analysis. Each PLM variable separated healthy persons from patients with Parkinsonism before administration of L-DOPA (area under the curve (AUC) = 0.94–0.99, p <.001 for any separate variable). A combination of (MT_off – MT_on)/MT_off and MT_on had the highest ability to separate patients with PD from patients with atypical Parkinsonism (area under the curve = 0.91, p <.001). The PLM test discriminates between healthy controls and patients with Parkinsonism, and between patients with Parkinson's disease and patients with atypical Parkinsonism.

[Supplementary material is available for this article. Go to the publisher's online edition of Journal of Motor Behavior for the following free supplemental resource: supplementary data.]     

Disturbance of spontaneous and posed facial expressions in Parkinson's disease

The effects of Parkinson's disease (PD) on spontaneous and posed facial activity and on the control of facial muscles were assessed by comparing 22 PD patients with 22 controls. Facial activity was analysed using the Facial Action Coding System (FACS; Ekman & Friesen, 1978). As predicted, PD patients showed reduced levels of spontaneous and posed facial expression in reaction to unpleasant odours compared to controls. PD patients were less successful than controls in masking or intensifying negative facial expressions. PD patients were also less able than controls to imitate specific facial muscle movements, but did not differ in the ability to pose emotional facial expressions. These results suggest that not only is spontaneous facial activity disturbed in PD, but also to some degree the ability to pose facial expressions, to mask facial expressions with other expressions, and to deliberately move specific muscles in the face.     

Cluster analysis reveals distinct patterns of saccade impairment and their relation to cognitive profiles in Parkinson's disease

Saccade performance has been reported to be altered in Parkinson's disease (PD), however, with a large variability between studies as both motor and cognitive impairment interfere with oculomotor control. The aim of this study was to identify different patterns in saccade alterations in PD using a data-driven approach and to explore their relationship with cognitive phenotypes. Sixty-one participants with PD and 25 controls performed eye-tracking (horizontal and vertical prosaccades, antisaccades) and neuropsychological testing. Hierarchical cluster analysis was applied to the eye-tracking data to subsequently compare the clusters based on demographical, clinical and cognitive characteristics. The three identified clusters of saccade alterations differed in cognitive profiles from healthy controls, but not in PD-related motor symptoms or demographics. The rate of directive errors in the antisaccade task was increased in clusters 1 and 2. Further, cluster 1 was defined by a general disinhibition of reflexive saccades and executive dysfunction in the neuropsychological evaluation. In cluster 2, prolonged saccade latencies and hypometria were accompanied by multidomain cognitive impairment. The cluster 3 showed increased antisaccade latency and vertical hypometria despite lack of evidence for cognitive impairment. Our results suggest that there may be at least two opposing patterns of saccade alterations associated with cognitive impairment in PD, which may explain some of the contradictory results of previous studies.