Hypomimia in Parkinson’s disease: an axial sign responsive to levodopa

The Story behind the Mask: A Narrative Review on Hypomimia in Parkinson's Disease

Facial movements are crucial for social and emotional interaction and well-being. Reduced facial expressions (i.e., hypomimia) is a common feature in patients with Parkinson's disease (PD) and previous studies linked this manifestation to both motor symptoms of the disease and altered emotion recognition and processing. Nevertheless, research on facial motor impairment in PD has been rather scarce and only a limited number of clinical evaluation tools are available, often suffering from poor validation processes and high inter- and intra-rater variability. In recent years, the availability of technology-enhanced quantification methods of facial movements, such as automated video analysis and machine learning application, led to increasing interest in studying hypomimia in PD. In this narrative review, we summarize the current knowledge on pathophysiological hypotheses at the basis of hypomimia in PD, with particular focus on the association between reduced facial expressions and emotional processing and analyze the current evaluation tools and management strategies for this symptom, as well as future research perspectives.

Facial emotion recognition deficits are associated with hypomimia and related brain correlates in Parkinson's disease

Hypomimia is a frequent manifestation in Parkinson's disease (PD) that can affect interpersonal relationships and quality of life. Recent studies have suggested that hypomimia is not only related to motor dysfunction but also to impairment in emotional processing networks. Therefore, we hypothesized that the severity of hypomimia could be associated with performance on a task aimed at assessing facial emotion recognition. In this study, we explored the association between hypomimia, recognition of facial expressions of basic emotions using the Ekman 60 Faces Test (EF), and brain correlates of both hypomimia and performance on the EF. A total of 94 subjects underwent clinical assessments (neurological and neuropsychological examinations), and 56 of them participated in the neuroimaging study. We found significant correlation between hypomimia, EF Disgust (r = -0.242, p = 0.022) and EF Happiness (r = -0.264, p = 0.012); an independent reduction in Cortical Thickness (Cth) in the postcentral gyrus, insula, middle and superior temporal gyri, supramarginal gyrus, banks of the superior temporal sulcus, bilateral fusiform gyri, entorhinal cortex, parahippocampal gyrus, inferior and superior parietal cortex, and right cuneus and precuneus; and multiple correlations between negative emotions such as EF Disgust or EF Anger and a reduced Cth in fronto-temporo-parietal regions. In conclusion, these results suggest that the association between hypomimia and emotion recognition deficits in individuals with PD might be mediated by shared circuits, supporting the concept that hypomimia is not only the result of the dysfunction of motor circuits, but also of higher cognitive functions.

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.

Computerized analysis of hypomimia and hypokinetic dysarthria for improved diagnosis of Parkinson's disease

Background and Objective

An aging society requires easy-to-use approaches for diagnosis and monitoring of neurodegenerative disorders, such as Parkinson's disease (PD), so that clinicians can effectively adjust a treatment policy and improve patients' quality of life. Current methods of PD diagnosis and monitoring usually require the patients to come to a hospital, where they undergo several neurological and neuropsychological examinations. These examinations are usually time-consuming, expensive, and performed just a few times per year. Hence, this study explores the possibility of fusing computerized analysis of hypomimia and hypokinetic dysarthria (two motor symptoms manifested in the majority of PD patients) with the goal of proposing a new methodology of PD diagnosis that could be easily integrated into mHealth systems.

Methods

We enrolled 73 PD patients and 46 age- and gender-matched healthy controls, who performed several speech/voice tasks while recorded by a microphone and a camera. Acoustic signals were parametrized in the fields of phonation, articulation and prosody. Video recordings of a face were analyzed in terms of facial landmarks movement. Both modalities were consequently modeled by the XGBoost algorithm.

Results

The acoustic analysis enabled diagnosis of PD with 77% balanced accuracy, while in the case of the facial analysis, we observed 81% balanced accuracy. The fusion of both modalities increased the balanced accuracy to 83% (88% sensitivity and 78% specificity). The most informative speech exercise in the multimodality system turned out to be a tongue twister. Additionally, we identified muscle movements that are characteristic of hypomimia.

Conclusions

The introduced methodology, which is based on the myriad of speech exercises likewise audio and video modality, allows for the detection of PD with an accuracy of up to 83%. The speech exercise - tongue twisters occurred to be the most valuable from the clinical point of view. Additionally, the clinical interpretation of the created models is illustrated. The presented computer-supported methodology could serve as an extra tool for neurologists in PD detection and the proposed potential solution of mHealth will facilitate the patient's and doctor's life.

Does Black vs. White race affect practitioners' appraisal of Parkinson's disease?

Black patients are diagnosed with Parkinson's disease (PD) at half the rate as White patients. The reasons for this large disparity are unknown. Here, we review evidence that practitioner bias may contribute. A key sign of PD is hypomimia or decreased facial expressivity. However, practitioner bias surrounding facial expressivity in Black people versus White people may lead practitioners to appraise Black patients with hypomimia as having higher levels of facial expressivity. Furthermore, practitioner bias may cause them to characterize reduced facial expressivity as being due to negative personality traits, as opposed to a medical sign, in Black patients with hypomimia. This racial bias in the evaluation of hypomimia in Black versus White patients could profoundly impact subsequent referral decisions and rates of diagnosis of PD. Therefore, exploring these differences is expected to facilitate addressing health care disparities through earlier and more accurate detection of PD in Black patients.

Sex Differences in Motor and Non-Motor Symptoms among Spanish Patients with Parkinson's Disease

BACKGROUND AND OBJECTIVE

Sex plays a role in Parkinson's disease (PD) mechanisms. We analyzed sex difference manifestations among Spanish patients with PD.

PATIENTS AND METHODS

PD patients who were recruited from the Spanish cohort COPPADIS from January 2016 to November 2017 were included. A cross-sectional and a two-year follow-up analysis were conducted. Univariate analyses and general linear model repeated measure were used.

RESULTS

At baseline, data from 681 PD patients (mean age 62.54 ± 8.93) fit the criteria for analysis. Of them, 410 (60.2%) were males and 271 (39.8%) females. There were no differences between the groups in mean age (62.36 ± 8.73 vs. 62.8 ± 9.24; p = 0.297) or in the time from symptoms onset (5.66 ± 4.65 vs. 5.21 ± 4.11; p = 0.259). Symptoms such as depression (p < 0.0001), fatigue (p < 0.0001), and pain (p < 0.00001) were more frequent and/or severe in females, whereas other symptoms such as hypomimia (p < 0.0001), speech problems (p < 0.0001), rigidity (p < 0.0001), and hypersexuality (p < 0.0001) were more noted in males. Women received a lower levodopa equivalent daily dose (p = 0.002). Perception of quality of life was generally worse in females (PDQ-39, p = 0.002; EUROHIS-QOL8, p = 0.009). After the two-year follow-up, the NMS burden (Non-Motor Symptoms Scale total score) increased more significantly in males (p = 0.012) but the functional capacity (Schwab and England Activities of Daily Living Scale) was more impaired in females (p = 0.001).

CONCLUSION

The present study demonstrates that there are important sex differences in PD. Long-term prospective comparative studies are needed.

A Pilot Trial of Dopamine Replacement for Dynamic Facial Expressions in Parkinson's Disease

Background

Current conflict exists regarding the potential beneficial effects of dopamine medications on facial expressivity in Parkinson's disease. Via digital video analysis software, we previously found reduced facial movement (entropy) and slower time to reach peak entropy in individuals with Parkinson's disease compared to controls.

Objectives

We aimed to determine whether levodopa medications improved parameters of dynamic facial expressions (amplitude, speed).

Methods

A total of 34 individuals with idiopathic Parkinson's disease were videotaped making voluntary facial expressions (happy, fear, anger, disgust) when "on" and "off" levodopa. Participants were 52 to 80 years old, early to mid-stage disease, non-demented, and included more men (65%). Expressions were digitized and analyzed using software that extracted three variables: two indices of movement change (total entropy, percent entropy change) and time to reach peak expression.

Results

Indices of facial movement (total entropy, peak entropy) and timing were significantly improved when patients were "on" vs "off" medication (all F's ≥ 3.00, P < 0.05). For total movement and time to reach peak entropy, levodopa-related improvements were emotion nonspecific. Levodopa-related improvement for peak entropy was driven primarily by happy expressions. There was no relationship between quantitative indices and clinical measures of mood (depression, anxiety) and motor disease severity.

Conclusion

The effects of levodopa on Parkinson's disease voluntary facial movement and on timing were robust and consistent with those of levodopa on other intentional movements in Parkinson's disease. This improvement possibly occurred because of levodopa enhanced activation of face representation areas in fronto-cortical regions or because of less movement-based suppression.

May Bradykinesia Features Aid in Distinguishing Parkinson's Disease, Essential Tremor, And Healthy Elderly Individuals?

BACKGROUND

Bradykinesia is the hallmark feature of Parkinson's disease (PD); however, it can manifest in other conditions, including essential tremor (ET), and in healthy elderly individuals.

OBJECTIVE

Here we assessed whether bradykinesia features aid in distinguishing PD, ET, and healthy elderly individuals.

METHODS

We conducted simultaneous video and kinematic recordings of finger tapping in 44 PD patients, 69 ET patients, and 77 healthy elderly individuals. Videos were evaluated blindly by expert neurologists. Kinematic recordings were blindly analyzed. We calculated the inter-raters agreement and compared data among groups. Density plots assessed the overlapping in the distribution of kinematic data. Regression analyses and receiver operating characteristic curves determined how the kinematics influenced the likelihood of belonging to a clinical score category and diagnostic group.

RESULTS

The inter-rater agreement was fair (Fleiss K = 0.32). Rater found the highest clinical scores in PD, and higher scores in ET than healthy elderly individuals (p < 0.001). In regard to kinematic analysis, the groups showed variations in movement velocity, with PD presenting the slowest values and ET displaying less velocity than healthy elderly individuals (all ps < 0.001). Additionally, PD patients showed irregular rhythm and sequence effect. However, kinematic data significantly overlapped. Regression analyses showed that kinematic analysis had high specificity in differentiating between PD and healthy elderly individuals. Nonetheless, accuracy decreased when evaluating subjects with intermediate kinematic values, i.e., ET patients.

CONCLUSION

Despite a considerable degree of overlap, bradykinesia features vary to some extent in PD, ET, and healthy elderly individuals. Our findings have implications for defining bradykinesia and categorizing patients.

Technology-based therapy-response evaluation of axial motor symptoms under daily drug regimen of patients with Parkinson’s disease

Background

Axial disturbances are the most disabling symptoms of Parkinson’s disease (PD). Kinect-based objective measures could extract motion characteristics with high reliability and validity.

Purpose

The present research aimed to quantify the therapy–response of axial motor symptoms to daily medication regimen and to explore the correlates of the improvement rate (IR) of axial motor symptoms based on a Kinect camera.

Materials and methods

We enrolled 44 patients with PD and 21 healthy controls. All 65 participants performed the Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale part III and the Kinect-based kinematic evaluation to assess arising from a chair, gait, posture, and postural stability before and after medication. Spearman’s correlation analysis and multiple linear regression model were performed to explore the relationships between motor feature IR and clinical data.

Results

All the features arising from a chair (P = 0.001), stride length (P = 0.001), velocity (P < 0.001), the height of foot lift (P < 0.001), and turning time (P = 0.001) improved significantly after a daily drug regimen in patients with PD. In addition, the anterior trunk flexion (lumbar level) exhibited significant improvement (P = 0.004). The IR of the axial motor symptoms score was significantly correlated with the IRs of kinematic features for gait velocity, stride length, foot lift height, and sitting speed (r_s = 0.345, P = 0.022; r_s = 0.382, P = 0.010; r_s = 0.314, P = 0.038; r_s = 0.518, P < 0.001, respectively). A multivariable regression analysis showed that the improvement in axial motor symptoms was associated with the IR of gait velocity only (β = 0.593, 95% CI = 0.023–1.164, P = 0.042).

Conclusion

Axial symptoms were not completely drug-resistant, and some kinematic features can be improved after the daily medication regimen of patients with PD.

Automated video-based assessment of facial bradykinesia in de-novo Parkinson's disease

Even though hypomimia is a hallmark of Parkinson’s disease (PD), objective and easily interpretable tools to capture the disruption of spontaneous and deliberate facial movements are lacking. This study aimed to develop a fully automatic video-based hypomimia assessment tool and estimate the prevalence and characteristics of hypomimia in de-novo PD patients with relation to clinical and dopamine transporter imaging markers. For this cross-sectional study, video samples of spontaneous speech were collected from 91 de-novo, drug-naïve PD participants and 75 age and sex-matched healthy controls. Twelve facial markers covering areas of forehead, nose root, eyebrows, eyes, lateral canthal areas, cheeks, mouth, and jaw were used to quantitatively describe facial dynamics. All patients were evaluated using Movement Disorder Society-Unified PD Rating Scale and Dopamine Transporter Single-Photon Emission Computed Tomography. Newly developed automated facial analysis tool enabled high-accuracy discrimination between PD and controls with area under the curve of 0.87. The prevalence of hypomimia in de-novo PD cohort was 57%, mainly associated with dysfunction of mouth and jaw movements, and decreased variability in forehead and nose root wrinkles (p < 0.001). Strongest correlation was found between reduction of lower lip movements and nigro-putaminal dopaminergic loss (r = 0.32, p = 0.002) as well as limb bradykinesia/rigidity scores (r = −0.37 p < 0.001). Hypomimia represents a frequent, early marker of motor impairment in PD that can be robustly assessed via automatic video-based analysis. Our results support an association between striatal dopaminergic deficit and hypomimia in PD.

A Spatio-Temporal Hypomimic Deep Descriptor to Discriminate Parkinsonian Patients

The hypomimia is a main clinical sign of Parkinson disease that describes motor patterns associated with the reduction and progressive loss of facial expression. This clinical sign constitutes a main biomarker to support diagnosis, even at early stages, and to establish progression and description of the disease. In clinical routine, the evaluation of such signs remains subjective or limited to the description of some landmarks that poorly describe little expressions correlated with the disease. This work introduces a new digital biomarker, expressed as a spatio-temporal convolutional representation that learns facial movement patterns to discriminate between Parkinson and control patients. The proposed architecture builds a representation through 3D convolutional layers, which are integrated from inception modules, achieving salient maps of face expression activations. This approach was validated in a retrospective study that includes 16 Parkinson patients and 16 control subjects. The architecture achieves an average accuracy of 91.87% using 480 video sequences in classification condition task. Clinical relevance- A digital descriptor that quantify ges-tural face signatures described from a deep spatio-temporal representation with the capability to discriminate Parkinsonian patients.

Hypomimia May Influence the Facial Emotion Recognition Ability in Patients with Parkinson's Disease

BACKGROUND

Hypomimia is a clinical feature of Parkinson's disease (PD). Based on the embodied simulation theory, the impairment of facial mimicry may worsen facial emotion recognition; however, the empirical results are inconclusive.

OBJECTIVE

We aimed to explore the worsening of emotion recognition by hypomimia. We further explored the relationship between the hypomimia, emotion recognition, and social functioning.

METHODS

A total of 114 participants were recruited. The patients with PD and normal controls (NCs) were matched for demographic characteristics. All the participants completed the Mini-Mental State Examination and the Chinese Multi-modalities Emotion Recognition Test. In addition to the above tests, the patients were assessed with the Movement Disorder Society-Unified Parkinson's Disease Rating Scale and Parkinson's Disease Social Functioning Scale (PDSFS).

RESULTS

Patients with PD with hypomimia had worse recognition of disgust than NCs (p = 0.018). The severity of hypomimia was predictive of the recognition of disgust (β= -0.275, p = 0.028). Facial emotion recognition was predictive of the PDSFS score of PD patients (β= 0.433, p = 0.001). We also found that recognizing disgust could mediate the relationship between hypomimia and the PDSFS score (β= 0.264, p = 0.045).

CONCLUSION

Patients with hypomimia had the worst disgust facial recognition. Hypomimia may affect the social function of PD patients, which is related to recognizing the expression of disgust. Emotion recognition training may improve the social function of patients with PD.

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.

Subthalamic Nucleus Stimulation in Parkinson's Disease: 5-Year Extension Study of a Randomized Trial

Background

In Parkinson's disease (PD) long-term motor outcomes of subthalamic nucleus deep brain stimulation (STN-DBS) are well documented, while comprehensive reports on non-motor outcomes are fewer and less consistent.

Objective

To report motor and non-motor symptoms after 5-years of STN-DBS.

Methods

We performed an open 5-year extension study of a randomized trial that compared intraoperative verification versus mapping of STN using microelectrode recordings. Changes from preoperative to 5-years of STN-DBS were evaluated for motor and non-motor symptoms (MDS-UPDRS I-IV), sleep disturbances (PDSS), autonomic symptoms (Scopa-Aut), quality of life (PDQ-39) and cognition through a neuropsychological test battery. We evaluated whether any differences between the two randomization groups were still present, and assessed preoperative predictors of physical dependence after 5 years of treatment using logistic regression.

Results

We found lasting improvement of off-medication motor symptoms (total MDS-UPDRS III, bradykinetic-rigid symptoms and tremor), on-medication tremor, motor fluctuations, and sleep disturbances, but reduced performance across all cognitive domains, except verbal memory. Reduction of verbal fluency and executive function was most pronounced the first year and may thus be more directly related to the surgery than worsening in other domains. The group mapped with multiple microelectrode recordings had more improvement of bradykinetic-rigid symptoms and of PDQ-39 bodily discomfort sub-score, but also more reduction in word fluency. Older age was the most important factor associated with physical dependence after 5 years.

Conclusion

STN-DBS offers good long-term effects, including improved sleep, despite disease progression. STN-DBS surgery may negatively impact verbal fluency and executive function.

Measurement of the facial nerve thickness and its correlation with freezing phenomenon and hypomimia in Parkinson's disease

OBJECTIVE

Hypomimia is one of the diagnostic features in Parkinson's disease, and freezing blocks may also occur with the degenerative process. We investigated that the thickness of the cranial facial nerve that innervates facial expressions, and the relationship between bradymimia and freezing phenomena in these patients.

METHODS

We included 70 patients and healthy participants in this cross-sectional study. Clinical characteristics, modified Hoehn and Yahr (mHY) stages, Unified Parkinson's Disease Rating Scale (UPDRS) scores and Freezing of Gait Questionnaire (FOG-Q) scores of Parkinson's patients were recorded. FOG-Q was scored between 1 and 4 points. The thickness of the facial nerve and its neighborhoods of numerically equal groups were measured radiologically in the internal acoustic channel (IAC) with magnetic resonance imaging of temporal lobe. Right and left facial nerve thicknesses were compared.

RESULTS

The right facial nerve thicknesses of the patient and control groups were measured as 0.97 ± 0.12 mm and 1.20 ± 0.10 mm at the proximal level and 0.71 (0.69-0.81) mm and 1.21 (1.13-1.24) mm at the distal level, respectively (P < 0.001). Notably, the facial nerve was more atrophied on the right than on the left (P < 0.001). Facial nerve to IAC ratio (%) was significantly lower and cerebrospinal fluid thickness distance (%) measurement was significantly higher (P < 0.001). Also, the FOG-Q and facial nerve to IAC ratio were negatively correlated (P = 0.049, rho = -0.335).

CONCLUSIONS

Our study provides new information about the facial nerve and its neighborhoods and clinical relationships in individuals with PD. In studies investigating hypomimia and FOG in Parkinson's, neuroimaging of the facial nerve can also be used. These results need to be proven with more comprehensive studies.

Detection of hypomimia in patients with Parkinson's disease via smile videos

Background

Parkinson’s disease (PD) is a neurodegenerative disease characterized by the impairment of facial expression, known as hypomimia. Hypomimia has serious impacts on patients’ ability to communicate, and it is difficult to detect at early stages of the disease. Furthermore, due to bradykinesia or other reasons, it is inconvenient for PD patients to visit the hospital. Therefore, it is appealing to develop an auxiliary diagnostic method that remotely detects hypomimia.

Methods

We proposed an automatic detection system for Parkinson’s hypomimia based on facial expressions (DSPH-FE). DSPH-FE provides a convenient remote service for those who potentially suffer from hypomimia and only requires patients to input their facial videos. Specifically, patients can detect hypomimia through two aspects: geometric features and texture features. Geometric features focus on visually representing structures of facial muscles. Facial expression factors (FEFs) are used as the first metric to quantify the current activation state of the facial muscles. Facial expression change factors (FECFs) are subsequently used as the second metric to calculate the moving trajectories of the activation states in the videos. Geometric features primarily concentrate on spatial information, with little involvement of temporal information. Thus, the extended histogram of oriented gradients (HOG) algorithm is introduced. This algorithm can extract texture features within multiple continuous frames and incorporate the temporal information into the features. Finally, these features are applied to four machine learning algorithms to model the relationship between these features and hypomimia.

Results

The DSPH-FE detection system achieved the best performance when concatenating geometric features and texture features, resulting in a F1 score of 0.9997. The best F1 scores achieved with geometric features and texture features were 0.8286 and 0.9446, respectively. This indicated that both geometric features and texture features have an ability to predict hypomimia, and demonstrated that temporal information can boost the model performance. Thus, DSPH-FE is an effective supportive tool in the medical management of PD patients.

Conclusions

Comprehensive experiments demonstrated that proposed features fit well with real-world videos and are beneficial in the clinical diagnosis of hypomimia. In particular, hypomimia had a greater impact on eyes and mouths when patients are smiling.

Hypomimia in Parkinson's Disease: What Is It Telling Us?

Introduction: Amimia is one of the most typical features of Parkinson's disease (PD). However, its significance and correlation with motor and nonmotor symptoms is unknown. The aim of this study is to evaluate the association between amimia and motor and nonmotor symptoms, including cognitive status, depression, and quality of life in PD patients. We also tested the blink rate as a potential tool for objectively measuring upper facial bradykinesia. Methods: We prospectively studied amimia in PD patients. Clinical evaluation was performed using the Unified Parkinson's Disease Rating Scale (UPDRS) and timed tests. Cognitive status, depression, and quality of life were assessed using the Parkinson's Disease Cognitive Rating Scale (PD-CRS), the 16-Item Quick Inventory of Depressive Symptomatology (QIDS-SR16), and the PDQ-39, respectively. Amimia was clinically evaluated according to item 19 of UPDRS III. Finally, we studied upper facial amimia by measuring resting blink frequency and blink rate during spontaneous conversation. Results: We included 75 patients. Amimia (item 19 UPDRS III) correlated with motor and total UPDRS (r: 0.529 and 0.551 Spearman), and its rigidity, distal bradykinesia, and motor axial subscores (r: 0.472; r: 0.252, and r: 0.508, respectively); Hoehn and Yahr scale (r: 0.392), timed tests, gait freezing, cognitive status (r: 0.29), and quality of life (r: 0.268) correlated with amimia. Blinking frequency correlated with amimia (measured with item 19 UPDRS), motor and total UPDRS. Conclusion: Amimia correlates with motor (especially axial symptoms) and cognitive situations in PD. Amimia could be a useful global marker of overall disease severity, including cognitive decline.

The role of the dorsal striatum in the recognition of emotions expressed by voice in Parkinson's disease

BACKGROUND AND PURPOSE

Non-motor impairment such as emotion recognition deficit in both facial and vocal expressions has been previously reported in Parkinson's disease (PD). We investigated whether the decoding of emotional prosody is impaired in PD and whether this deficit is related to striatal damage.

METHODS

Fifteen PD patients and 15 healthy controls (HCs) were requested to listen to six audio tracks and to recognize the emotions expressed by a professional actor while reading a meaning-neutral sentence. All subjects also received a structural MRI examination. Volumetric measurements were extracted for the striatum, a key region involved in emotional processing and typically impaired in PD.

RESULTS

Decoding sadness conveyed by voice was impaired in PD compared with HC and was related to the volume of the dorsal striatum bilaterally.

CONCLUSIONS

The dorsal striatum is involved in the decoding of vocal negative emotions in PD.