Subjective Cognitive Complaints in Parkinson's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Subjective cognitive complaints (SCCs) in Parkinson's disease (PD) are reported frequently, but their prevalence and association with changes on objective testing are not fully known. OBJECTIVE: We aimed to determine the prevalence, clinical correlates, and predictive value of SCCs in PD. METHODS: We conducted a systematic review and meta-analysis. From 204 abstracts, we selected 31 studies (n = 3441 patients), and from these, identified the prevalence, clinical features, associations with neuropsychiatric symptoms, and predictive values of SCCs in PD. RESULTS: The meta-analysis showed an SCC prevalence of 36%. This prevalence, however, was significantly moderated by study heterogeneity regarding female sex, disease severity, levodopa equivalent daily dosage, exclusion from the overall sample of patients with objective cognitive impairment, and measurement instrument. SCC prevalence did not differ between de novo and treated PD patients. SCCs were weakly and negligibly associated with cognitive changes on objective testing in cross-sectional studies. However, in cognitively healthy patients, SCCs had a risk ratio of 2.71 for later cognitive decline over a mean follow-up of 3.16 years. Moreover, SCCs were moderately related to co-occurring symptoms of depression, anxiety, or apathy and were more strongly related to these neuropsychiatric symptoms than objective cognitive functioning. CONCLUSION: Our analyses suggest that SCCs in patients with and without objective cognitive impairment are frequent, occurring in more than one third of PD patients. Establishing uniform measurement instruments for identifying PD-related SCCs is critical to understand their implications. Even in cases lacking evidence of objective cognitive impairment and where SCCs might reflect underlying neuropsychiatric symptoms, the possibility of later cognitive deterioration should not be excluded. Therefore, SCCs in PD patients warrant close monitoring for opportunities for targeted and effective interventions. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Facial emotion expressivity in patients with Parkinson's and Alzheimer's disease.

Parkinson's disease (PD) and Alzheimer's disease (AD) are neurodegenerative disorders with some overlapping clinical features. Hypomimia (reduced facial expressivity) is a prominent sign of PD and it is also present in AD. However, no study has experimentally assessed hypomimia in AD and compared facial expressivity between PD and AD patients. We compared facial emotion expressivity in patients with PD, AD, and healthy controls (HCs). Twenty-four PD patients, 24 AD patients and 24 HCs were videotaped during neutral facial expressions and while posing six facial emotions (anger, surprise, disgust, fear, happiness, and sadness). Fifteen raters were asked to evaluate the videos using MDS-UPDRS-III (item 3.2) and to identify the corresponding emotion from a seven-forced-choice response format. We measured the percentage of accuracy, the reaction time (RT), and the confidence level (CL) in the perceived accuracy of the raters' responses. We found the highest MDS-UPDRS 3.2 scores in PD, and higher in AD than HCs. When evaluating the posed expression captures, raters identified a lower percentage of correct answers in the PD and AD groups than HCs. There was no difference in raters' response accuracy between the PD and AD. No difference was observed in RT and CL data between groups. Hypomimia in patients correlated positively with the global MDS-UPDRS-III and negatively with Mini Mental State Examination scores. PD and AD patients have a similar pattern of reduced facial emotion expressivity compared to controls. These findings hold potential pathophysiological and clinical implications.

Compassionate mind training for people with Parkinson's disease: A pilot study and predictors of response.

INTRODUCTION: People with Parkinson's disease (PD) often present with disabling neuropsychiatric symptoms. Compassionate mind training (CMT) is a psychological approach effective in reducing stress and promoting psychological well-being. Heart rate variability (HRV), a measure reflecting sympathovagal balance, has been associated with psychological well-being and a compassionate attitude. AIM: To assess the feasibility and effectiveness of CMT in enhancing the quality of life and psychological well-being in PD patients. Additionally, we evaluated HRV as a physiomarker for assessing the CMT outcomes. METHODS: Twenty-four PD patients participated in the study. A 6-week online CMT intervention was delivered on a weekly basis. At baseline and post-intervention patients completed questionnaires assessing depression, anxiety and quality of life. In a subsample of 11 patients, HRV was measured at baseline and post-intervention in three conditions: at rest, during stress and after 3 min of deep breathing. RESULTS: The attendance rate was 94.3%. Quality of life and perceived stigma improved post-intervention as compared with baseline (p = 0.02 and p = 0.03 for PD Questionnaire-39 total score and Stigma subscore, respectively). After CMT, patients presented better physiological regulation to stress, as measured by higher HRV as compared with baseline (p = 0.005). Notably, patients who were more resilient to stress at baseline (less decrease in HRV during stress) experienced a more substantial reduction in anxiety and depression following CMT. CONCLUSIONS: CMT is feasible and can improve quality of life and stigma in PD patients. HRV emerges as a promising physiomarker for predicting and measuring the outcomes of psychological interventions in PD.

Beta-triggered adaptive deep brain stimulation during reaching movement in Parkinson's disease.

Subthalamic nucleus (STN) beta-triggered adaptive deep brain stimulation (ADBS) has been shown to provide clinical improvement comparable to conventional continuous DBS (CDBS) with less energy delivered to the brain and less stimulation induced side effects. However, several questions remain unanswered. First, there is a normal physiological reduction of STN beta band power just prior to and during voluntary movement. ADBS systems will therefore reduce or cease stimulation during movement in people with Parkinson's disease and could therefore compromise motor performance compared to CDBS. Second, beta power was smoothed and estimated over a time period of 400 ms in most previous ADBS studies, but a shorter smoothing period could have the advantage of being more sensitive to changes in beta power, which could enhance motor performance. In this study, we addressed these two questions by evaluating the effectiveness of STN beta-triggered ADBS using a standard 400 ms and a shorter 200 ms smoothing window during reaching movements. Results from 13 people with Parkinson's disease showed that reducing the smoothing window for quantifying beta did lead to shortened beta burst durations by increasing the number of beta bursts shorter than 200 ms and more frequent switching on/off of the stimulator but had no behavioural effects. Both ADBS and CDBS improved motor performance to an equivalent extent compared to no DBS. Secondary analysis revealed that there were independent effects of a decrease in beta power and an increase in gamma power in predicting faster movement speed, while a decrease in beta event related desynchronization (ERD) predicted quicker movement initiation. CDBS suppressed both beta and gamma more than ADBS, whereas beta ERD was reduced to a similar level during CDBS and ADBS compared with no DBS, which together explained the achieved similar performance improvement in reaching movements during CDBS and ADBS. In addition, ADBS significantly improved tremor compared with no DBS but was not as effective as CDBS. These results suggest that STN beta-triggered ADBS is effective in improving motor performance during reaching movements in people with Parkinson's disease, and that shortening of the smoothing window does not result in any additional behavioural benefit. When developing ADBS systems for Parkinson's disease, it might not be necessary to track very fast beta dynamics; combining beta, gamma, and information from motor decoding might be more beneficial with additional biomarkers needed for optimal treatment of tremor.

Memory Phenotypes In Early, De Novo Parkinson's Disease Patients with Mild Cognitive Impairment.

BACKGROUND: Memory deficits in mild cognitive impairment related to Parkinson's disease (PD-MCI) are quite heterogeneous, and there is no general agreement on their genesis. OBJECTIVES: To define memory phenotypes in de novo PD-MCI and their associations with motor and non-motor features and patients' quality of life. METHODS: From a sample of 183 early de novo patients with PD, cluster analysis was applied to neuropsychological measures of memory function of 82 patients with PD-MCI (44.8%). The remaining patients free of cognitive impairment were considered as a comparison group (n = 101). Cognitive measures and structural magnetic resonance imaging-based neural correlates of memory function were used to substantiate the results. RESULTS: A three-cluster model produced the best solution. Cluster A (65.85%) included memory unimpaired patients; Cluster B (23.17%) included patients with mild episodic memory disorder related to a "prefrontal executive-dependent phenotype"; Cluster C (10.97%) included patients with severe episodic memory disorder related to a "hybrid phenotype," where hippocampal-dependent deficits co-occurred with prefrontal executive-dependent memory dysfunctions. Cognitive and brain structural imaging correlates substantiated the findings. The three phenotypes did not differ in terms of motor and non-motor features, but the attention/executive deficits progressively increased from Cluster A, through Cluster B, to Cluster C. This last cluster had worse quality of life compared to others. CONCLUSIONS: Our results demonstrated the memory heterogeneity of de novo PD-MCI, suggesting existence of three distinct memory-related phenotypes. Identification of such phenotypes can be fruitful in understanding the pathophysiological mechanisms underlying PD-MCI and its subtypes and in guiding appropriate treatments. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Quantitative Evaluation of Hypomimia in Parkinson's Disease: A Face Tracking Approach.

Parkinson's disease (PD) is a neurological disorder that mainly affects the motor system. Among other symptoms, hypomimia is considered one of the clinical hallmarks of the disease. Despite its great impact on patients' quality of life, it remains still under-investigated. The aim of this work is to provide a quantitative index for hypomimia that can distinguish pathological and healthy subjects and that can be used in the classification of emotions. A face tracking algorithm was implemented based on the Facial Action Coding System. A new easy-to-interpret metric (face mobility index, FMI) was defined considering distances between pairs of geometric features and a classification based on this metric was proposed. Comparison was also provided between healthy controls and PD patients. Results of the study suggest that this index can quantify the degree of impairment in PD and can be used in the classification of emotions. Statistically significant differences were observed for all emotions when distances were taken into account, and for happiness and anger when FMI was considered. The best classification results were obtained with Random Forest and kNN according to the AUC metric.

Neurophysiological Correlates of Trait Impulsivity in Parkinson's Disease.

BACKGROUND: Impulsivity is common in people with Parkinson's disease (PD), with many developing impulsive compulsive behavior disorders (ICB). Its pathophysiological basis remains unclear. OBJECTIVES: We aimed to investigate local field potential (LFP) markers of trait impulsivity in PD and their relationship to ICB. METHODS: We recorded subthalamic nucleus (STN) LFPs in 23 PD patients undergoing deep brain stimulation implantation. Presence and severity of ICB were assessed by clinical interview and the Questionnaire for Impulsive-Compulsive Disorders in PD-Rating Scale (QUIP-RS), whereas trait impulsivity was estimated with the Barratt Impulsivity Scale (BIS-11). Recordings were obtained during the off dopaminergic states and the power spectrum of the subthalamic activity was analyzed using Fourier transform-based techniques. Assessment of each electrode contact localization was done to determine the topography of the oscillatory activity recorded. RESULTS: Patients with (n = 6) and without (n = 17) ICB had similar LFP spectra. A multiple regression model including QUIP-RS, BIS-11, and Unified PD Rating Scale-III scores as regressors showed a significant positive correlation between 8-13 Hz power and BIS-11 score. The correlation was mainly driven by the motor factor of the BIS-11, and was irrespective of the presence or absence of active ICB. Electrode contact pairs with the highest α power, which also correlated most strongly with BIS-11, tended to be more ventral than contact pairs with the highest beta power, which localize to the dorsolateral motor STN. CONCLUSIONS: Our data suggest a link between α power and trait impulsivity in PD, irrespective of the presence and severity of ICB. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

GBA-Related Parkinson's Disease: Dissection of Genotype-Phenotype Correlates in a Large Italian Cohort.

BACKGROUND: Variants in GBA are the most common genetic risk factor for Parkinson's disease (PD). The impact of different variants on the PD clinical spectrum is still unclear. OBJECTIVES: We determined the frequency of GBA-related PD in Italy and correlated GBA variants with motor and nonmotor features and their occurrence over time. METHODS: Sanger sequencing of the whole GBA gene was performed. Variants were classified as mild, severe, complex, and risk. ß-glucocerebrosidase activity was measured. The Kaplan-Meier method and Cox proportional hazard regression models were performed. RESULTS: Among 874 patients with PD, 36 variants were detected in 14.3%, including 20.4% early onset. Patients with GBA-PD had earlier and more frequent occurrence of several nonmotor symptoms. Patients with severe and complex GBA-PD had the highest burden of symptoms and a higher risk of hallucinations and cognitive impairment. Complex GBA-PD had the lowest ß-glucocerebrosidase activity. CONCLUSIONS: GBA-PD is highly prevalent in Italy. Different types of mutations underlie distinct phenotypic profiles. © 2020 International Parkinson and Movement Disorder Society.

Khodakarami, H., et al., Prediction of the Levodopa Challenge Test in Parkinson's Disease Using Data from a Wrist-Worn Sensor. Sensors 2019, 19, 5153.

The authors wish to make the following erratum to this paper [...].

Embodied Precision: Intranasal Oxytocin Modulates Multisensory Integration.

Multisensory integration processes are fundamental to our sense of self as embodied beings. Bodily illusions, such as the rubber hand illusion (RHI) and the size-weight illusion (SWI), allow us to investigate how the brain resolves conflicting multisensory evidence during perceptual inference in relation to different facets of body representation. In the RHI, synchronous tactile stimulation of a participant's hidden hand and a visible rubber hand creates illusory body ownership; in the SWI, the perceived size of the body can modulate the estimated weight of external objects. According to Bayesian models, such illusions arise as an attempt to explain the causes of multisensory perception and may reflect the attenuation of somatosensory precision, which is required to resolve perceptual hypotheses about conflicting multisensory input. Recent hypotheses propose that the precision of sensorimotor representations is determined by modulators of synaptic gain, like dopamine, acetylcholine, and oxytocin. However, these neuromodulatory hypotheses have not been tested in the context of embodied multisensory integration. The present, double-blind, placebo-controlled, crossover study ( n = 41 healthy volunteers) aimed to investigate the effect of intranasal oxytocin (IN-OT) on multisensory integration processes, tested by means of the RHI and the SWI. Results showed that IN-OT enhanced the subjective feeling of ownership in the RHI, only when synchronous tactile stimulation was involved. Furthermore, IN-OT increased an embodied version of the SWI (quantified as estimation error during a weight estimation task). These findings suggest that oxytocin might modulate processes of visuotactile multisensory integration by increasing the precision of top-down signals against bottom-up sensory input.

Role of pedunculopontine nucleus in sleep-wake cycle and cognition in humans: A systematic review of DBS studies.

BACKGROUND: Animal studies have demonstrated that the pedunculopontine nucleus (PPN) is involved in the control of posture and gait, and that it is also a key structure in controlling basic non-motor functions such as sleep, attention and arousal. In this systematic review we aimed to evaluate all available studies assessing the role of PPN on cognition, nocturnal sleep and alertness in humans. Finally, we attempted to define a model in which PPN acts as an interface structure between motor control and behavior. METHODS: A systematic search of the computerized databases MEDLINE and PubMed was conducted to identify papers on PPN and cognitive functions, sleep and alertness. Key search terms included: 'PPN', 'arousal', 'sleep', 'cognition', 'memory', 'language', 'attention', 'alertness', 'PPN-DBS', 'Parkinson's and PPN', 'Parkinson's and PPN-DBS'. RESULTS: Twelve studies met our inclusion criteria and were included. All of them involved PD patients implanted with unilateral or bilateral PPN-DBS, most patients had concomitant DBS of another anatomical structure (subthalamic nucleus or Zona incerta). There is a lack of consistent evidences confirming the effect of PPN-DBS on specific cognitive functions, alertness or sleep in PD. There is heterogeneity between and within surgical centres of study protocols especially regarding DBS targeting, parameters of stimulation and experimental methods. Moreover, the available studies are limited by the small sample size and the short follow-up time. It has been suggested that low frequency stimulation (25 Hz) has a better effect compared to the high frequency one (60-80 Hz) on alertness, however this needs to be confirmed in further studies. CONCLUSIONS: PPN-DBS is a promising but yet an experimental procedure. PD represents an encouraging pathological model for future studies aiming to shade light on the role of PPN in cognition, attention and alertness in humans.

Treatment Recommendations for Tardive Dyskinesia.

BACKGROUND: Tardive dyskinesia is a movement disorder characterised by irregular, stereotyped, and choreiform movements associated with the use of antipsychotic medication. We aim to provide recommendations on the treatment of tardive dyskinesia. METHODS: We performed a systematic review of studies of the treatment of tardive dyskinesia. Studies were rated for methodological quality using the American Academy of Neurology Risk of Bias Classification system. Overall level of evidence classifications and grades of recommendation were made using the Scottish Intercollegiate Guidelines Network framework. RESULTS: Preventing tardive dyskinesia is of primary importance, and clinicians should follow best practice for prescribing antipsychotic medication, including limiting the prescription for specific indications, using the minimum effective dose, and minimising the duration of therapy. The first-line management of tardive dyskinesia is the withdrawal of antipsychotic medication if clinically feasible. Yet, for many patients with serious mental illness, the discontinuation of antipsychotics is not possible due to disease relapse. Switching from a first-generation to a second-generation antipsychotic with a lower D2 affinity, such as clozapine or quetiapine, may be effective in reducing tardive dyskinesia symptoms. The strongest evidence for a suitable co-intervention to treat tardive dyskinesia comes from tests with the new VMAT inhibitors, deutetrabenazine and valbenazine. These medications have not been approved for use in Canada. CONCLUSION: Data on tardive dyskinesia treatment are limited, and the best management strategy remains prevention. More long-term safety and efficacy data are needed for deutetrabenazine and valbenazine, and their routine availability to patients outside of the USA remains in question.

Prediction of the Levodopa Challenge Test in Parkinson's Disease Using Data from a Wrist-Worn Sensor.

The response to levodopa (LR) is important for managing Parkinson's Disease and is measured with clinical scales prior to (OFF) and after (ON) levodopa. The aim of this study was to ascertain whether an ambulatory wearable device could predict the LR from the response to the first morning dose. The ON and OFF scores were sorted into six categories of severity so that separating Parkinson's Kinetigraph (PKG) features corresponding to the ON and OFF scores became a multi-class classification problem according to whether they fell below or above the threshold for each class. Candidate features were extracted from the PKG data and matched to the class labels. Several linear and non-linear candidate statistical models were examined and compared to classify the six categories of severity. The resulting model predicted a clinically significant LR with an area under the receiver operator curve of 0.92. This study shows that ambulatory data could be used to identify a clinically significant response to levodopa. This study has also identified practical steps that would enhance the reliability of this test in future studies.

Can we predict development of impulsive-compulsive behaviours in Parkinson's disease?

OBJECTIVE: To determine clinical and structural imaging predictors of impulsive-compulsive behaviour (ICB) in de novo Parkinson's disease (PD). METHODS: From a cohort of 1116 subjects from the Parkinson's Progression Marker Initiative database, we created a subcohort of 42 de novo PD without ICB at baseline with available 3T MRI and who developed ICB during follow-up. PD-ICB were matched for age, gender and disease duration to 42 patients with PD without ICB over follow-up (PD-no-ICB) and 42 healthy controls (HCs). Baseline demographic and clinical predictors of ICB were analysed. For the longitudinal neuroimaging analysis, we selected 27 patients with PD-ICB with available neuroimaging after ICB onset, who were matched with 32 PD-no-ICB and 35 HCs. Baseline and longitudinal structural differences were compared using voxel-based morphometry and voxel-based quantification. RESULTS: People who went on to develop ICB had more severe anxiety, worse autonomic and global cognitive functions and were more likely to have rapid eye movement sleep behaviour disorder. Logistic regression confirmed that worse autonomic and cognitive functions were predictors of ICB. We could not find any morphological feature on baseline MRI that predicted later onset of ICB. When comparing PD groups at follow-up, a small region of increased atrophy in the anterior limb of the left internal capsule adjacent to the head of the left caudate nucleus was found in PD-ICB, but not surviving correction for multiple comparisons. CONCLUSIONS: Worse autonomic and cognitive functions predict development of ICB at the time of PD diagnosis. Structural imaging fails to identify morphological features associated with the development of ICB.

Pain processing in functional and idiopathic dystonia: An exploratory study.

BACKGROUND: Pain is often experienced by patients with functional dystonia and idiopathic cervical dystonia and is likely to be determined by different neural mechanisms. OBJECTIVE: In this exploratory study, we tested the sensory-discriminative and cognitive-emotional component of pain in patients with functional and idiopathic dystonia. METHODS: Ten patients with idiopathic cervical dystonia, 12 patients with functional dystonia, and 16 age- and sex-matched healthy controls underwent psychophysical testing of tactile and pain thresholds and pain tolerance. We delivered electrical pulses of increasing intensity to the index finger of each hand and the halluces of each foot. Pain threshold and pain tolerance were respectively defined as the (1) intensity at which sensation changed from unpainful to faintly painful and (2) intensity at which painful sensation was intolerable. RESULTS: No differences were found between the three groups for tactile and pain thresholds assessed in hands and feet. Pain tolerance was significantly increased in all body regions only in functional dystonia. Patients with continuous functional dystonia had higher pain tolerance compared to subjects with paroxysmal functional dystonia and idiopathic cervical dystonia. There was no correlation between pain tolerance and pain scores, depression, anxiety, disease duration, and motor disability in both groups. CONCLUSIONS: Patients with functional dystonia have a dissociation between the sensory-discriminative and cognitive-emotional components of pain, as revealed by normal pain thresholds and increased pain tolerance. Abnormal connectivity between the motor and limbic systems might account for abnormal pain processing in functional dystonia. © 2018 International Parkinson and Movement Disorder Society.

Emotional facedness in Parkinson's disease.

People with Parkinson's disease (PD) have a deficit of facial expression. Previous studies indicate that hemispheric dominance for emotional processing can give rise to an asymmetric pattern of facial expression of emotion. In this study, we aimed to evaluate possible asymmetry in facial emotion expressivity in PD. Twenty PD patients and twenty healthy controls were video-recorded while posing the 6 basic emotions. The most expressive pictures were derived from the videos and chimeric faces were created. Nine healthy raters were asked to judge which of the two chimeras looked more expressive. Chosen responses, reaction times and confidence levels were the main outcome measures. We evaluated possible differences in these measures within each group and between groups (PD, healthy controls). We assessed possible correlations between a global facial laterality index (pooling all emotions together) as well as facial laterality indexes for each emotion and the body laterality index, accounting for the predominant side of limb bradykinesia in patients. There was no difference in outcome measures when evaluating the two hemifaces within PD patients and healthy controls or between the two groups (all Ps > 0.05). In PD patients there was a correlation between the global facial laterality index and the body laterality index (R = - 0.39, P = 0.01), suggesting that the most expressive hemiface corresponded to the less affected body side. The results of our study do not support the hypothesis of hemisphere predominance in regulating facial emotion expressions and provides novel information on altered facial emotion expression in PD.

The Assessment and Treatment of Antipsychotic-Induced Akathisia.

BACKGROUND: Akathisia is a common and distressing neuropsychiatric syndrome associated with antipsychotic medication, characterised by subjective and objective psychomotor restlessness. The goal of this guideline is to provide clinicians with recommendations on the assessment and treatment of akathisia. METHODS: We performed a systematic review of therapeutic studies assessing the treatment of antipsychotic-induced extrapyramidal symptoms. Forty studies on akathisia and 4 systematic reviews evaluating the adverse effects of antipsychotics were used in the formulation of recommendations. Studies were rated for methodological quality using the American Academy of Neurology Risk of Bias Classification system. The overall level of evidence classifications and grades of recommendation were made using the Scottish Intercollegiate Guidelines Network framework. RESULTS: As a good practice point, clinicians should systematically assess akathisia with a validated scale before starting antipsychotics and during antipsychotic dosage titration. For the management of akathisia, there was adequate evidence to allow recommendations regarding antipsychotic dose reduction, antipsychotic polypharmacy, switching antipsychotic medication, and the use of adjuvant medications including beta-blockers, anticholinergics, 5HT2A antagonists, benzodiazepines, and vitamin B6. CONCLUSION: The treatment of antipsychotic-induced akathisia should be personalised, with consideration of antipsychotic dose reduction, cessation of antipsychotic polypharmacy, and switching to an antipsychotic with a perceived lower liability for akathisia, before the use of adjuvant medications. The choice of adjuvant medications should favour the more established treatments, with careful consideration of contraindications and side effects. Limitations in the evidence should be acknowledged and prompt cautious prescribing, particularly with respect to the duration of use of adjuvant medications, is warranted.

Mental rotation and working memory in musicians' dystonia.

BACKGROUND: Mental rotation of body parts engages cortical-subcortical areas that are actually involved in the execution of a movement. Musicians' dystonia is a type of focal hand dystonia that is grouped together with writer's cramp under the rubric of "occupational dystonia", but it is unclear to which extent these two disorders share common pathophysiological mechanisms. Previous research has demonstrated patients with writer's cramp to have deficits in mental rotation of body parts. It is unknown whether patients with musicians' dystonia would display similar deficits, reinforcing the concept of shared pathophysiology. METHODS: Eight patients with musicians' dystonia and eight healthy musicians matched for age, gender and musical education, performed a number of tasks assessing mental rotation of body parts and objects as well as verbal and spatial working memories abilities. RESULTS: There were no differences between patients and healthy musicians as to accuracy and reaction times in any of the tasks. CONCLUSIONS: Patients with musicians' dystonia have intact abilities in mentally rotating body parts, suggesting that this disorder relies on a highly selective disruption of movement planning and execution that manifests only upon playing a specific instrument. We further demonstrated that mental rotation of body parts and objects engages, at least partially, different cognitive networks.

Sense of body ownership in patients affected by functional motor symptoms (conversion disorder).

BACKGROUND AND AIM: Patients with functional neurological symptoms are commonly seen in neurological practice. Nevertheless their aetiopathology remains unclear. We have recently shown that patients affected by functional motor symptoms (FMS) present lower interoceptive awareness and higher alexithymia levels than healthy controls. Nevertheless sense of body ownership has never been studied in FMS patients. The aim of the present study was to systematically investigate the sense of body ownership, with the rubber hand illusion (RHI) paradigm, in patients with FMS and healthy controls. MATERIALS AND METHODS: We included in the study 16 patients with FMS and 18 healthy controls (HC). Patients and HC were asked to complete the Toronto Alexithymia Scale (TAS-20) and the self-consciousness scale (self-objectification questionnaire). All participants underwent the RHI paradigm: illusionary experience was measured by self-report and by proprioceptive alteration. RESULTS: A Mann-Whitney U test performed revealed that FMS (median=2.11) participants embodied the rubber hand to the same extent than HC participants (median=2.0, Z = -0.86, p>0.05, r = -0.15). The same test revealed no significant difference in the Proprioceptive Drift experience between FMS (median=0.0) and HC participants (median = -0.5, Z = -0.96, p>0.05, r = -0.16). CONCLUSIONS: Our study revealed that sense of body ownership is not impaired in patients affected by FMS. This, together with the results from our previous experiment (studying the interoceptive awareness), supports the hypothesis that interoceptive awareness and sense of body ownership may be dissociated in patients with FMS.

Rehabilitation of hypomimia in Parkinson's disease: a feasibility study of two different approaches.

Parkinson's disease (PD) patients frequently have an impairment of facial expression both in voluntary and spontaneous emotional expression. Aim of this study was to evaluate the feasibility of a rehabilitation program for hypomimia in patients with PD, comparing two different approaches. Thirty-six patients with PD were included: 20 patients received a rehabilitative intervention for hypomimia either with a DVD showing exercises focused on facial muscles (PD-group-A) or with a therapist-guided facial rehabilitation with a proprioceptive/recognition approach (PD-group-B). Sixteen patients (PD-Ctrl group) did not receive any treatment and served as control group. The feasibility of the proposed rehabilitation techniques was the main focus of this evaluation. We also evaluate the efficacy of the treatments by means of the sub-item 19 of the Unified Parkinson's disease Rating Scale motor score (UPDRS-III) and by a computerized analysis of facial expression (E-Motion), which was assessed prior to (T0) and after therapy (T1). The proposed rehabilitative program for the treatment of hypomimia was shown to be feasible. Our data show a significant improvement in UPDRS-III sub-item 19 in PD-group-B compared to PD-group-A, (p = 0.005) and to PD-Ctrl (p = 0.003) and in expressivity of fear in PD-group-B compared to PD-Ctrl (p = 0.01). The proposed rehabilitative program showed to be feasible. A larger multi-center trial is now warranted to establish its efficacy to improve facial expression over long time period.