Evaluation of Post-Swallow Residue with Visual Analysis of Swallowing Efficiency and Safety in Patients with Idiopathic Parkinson's Disease

Objectives: Dysphagia is common in idiopathic Parkinson's disease (IPD) and is associated with impairments in both swallowing safety and swallowing efficiency. The goals of this study were to define post-swallow residue patterns in people with IPD and describe pathophysiological endoscopic findings affecting residue accumulation. Methods: This was a prospective single-blinded cross-sectional cohort study of patients with the diagnosis of IPD recruited from a Movement Disorder Clinic. Clinical variables included patient age, cognitive function, and measures of disease severity, and laryngoscopic examinations with a flexible endoscopic evaluation of swallowing (FEES) were completed for each patient. Visual Analysis of Swallowing Efficiency and Safety (VASES) was used to analyze FEES. Post-swallow residue outcomes and non-residue endoscopic outcomes including the Bowing index, Penetration Aspiration Scale (PAS) score, premature leakage, and build-up phenomenon were evaluated. Multiple regression models were used to evaluate factors affecting the residue at different anatomic levels. Results: Overall 53 patients completed the study. The multiple regression analyses showed a relation between (1) the presence of residue at the level of oropharynx and epiglottis with premature leakage, (2) the presence of residue at the level of the laryngeal vestibule and vocal folds with build-up phenomenon, and (3) the presence of residue at the level of the hypopharynx, laryngeal vestibule, and subglottis with airway invasion. Conclusion: Residue pattern during FEES is associated with specific swallow dysfunctions in IPD. Using residue localization and quantification may be a helpful tool in assessing the impact of targeted swallowing interventions in patients with IPD and dysphagia.

Sexual Dysfunction Among Egyptian Idiopathic Parkinson's Disease Patients

BACKGROUND

One of the non-motor features of idiopathic Parkinson's disease (IPD) is sexual dysfunction (SD) which is under-recognized and, consequently, undertreated. This study aimed to evaluate SD in patients with IPD.

PATIENTS AND METHODS

The study was conducted on 67 IPD patients; 30 healthy subjects with age and gender matching with the patients served as the control group. All participants were subjected to sexual function assessment using the Arabic version of Arizona Sexual Experience Scale (ASEX), Mini-Mental State Examination (MMSE), and Beck Depression Inventory (BDI), while the severity of IPD was assessed using the modified Hoehn and Yahr scoring scale and MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS).

RESULTS

There were no statistically significant differences between patients with IPD and the control group regarding MMSE, hypertension, diabetes mellitus, or dyslipidemia. However, BDI scores were significantly higher in patients with IPD. The rate of SD among our patients was 64% compared to 30% in the control group. The total score and subscales of ASEX were significantly higher in IPD patients than in controls. SD showed a significant correlation with the severity of the IPD irrespective of other variables, including patient age, sex, disease duration, hypertension, diabetes, dyslipidemia, smoking, and dose of L-dopa.

CONCLUSION

SD is a commonly underrated feature in patients with IPD; it should be investigated carefully as it is an important non-motor symptom that correlates with disease severity.

Comparison of the Effects of COVID-19 Pandemic on Male and Female Gender in Patients Diagnosed with Idiopathic Parkinson's Disease: A Case of Sakarya Province, Turkey

INTRODUCTION

The study aims to evaluate the motor, non-motor, cognitive and psychiatric conditions of our patients diagnosed with Idiopathic Parkinson's Disease (IPD) before and after the COVID-19 pandemic and to investigate the effect of the pandemic on male and female genders.

METHODS

Ninety patients were included in the study. Demographic data such as age, gender, and duration of disease, type of disease of the patients were recorded. Patients were then divided into 2 groups: male and female. Movement disorders of both groups before the pandemic, disease stage determined by H&Y and UPDRS at the admission and after the pandemic, Levodopa equivalent dose used were recorded and all patients were surveyed to evaluate their motor, non-motor, cognitive, and psychiatric conditions during the COVID-19 pandemic. The effects of the COVID-19 pandemic on male and female genders were investigated.

RESULTS

Of the patients, 40 were male and 50 were female. Daytime drowsiness, weakness, impaired walking, constipation, sleep disorders, and inability to turn in the bed worsened compared to the period before the pandemic. Yet, of the psychiatric symptoms, boredom, unhappiness, anhedonia, irritability, and tension were found to increase during the pandemic. There was a statistically significant difference in UPDRS, H&Y and disease stages before and after the COVID-19 pandemic in both groups, especially in the female group (p<0.05).

CONCLUSION

Although it was more pronounced in female patients with IPD diagnosis, both motor and non-motor symptoms were found to worsen during the COVID-19 pandemic in both groups.

The Role of Monoaminergic Tones and Brain Metabolism in Cognition in De Novo Parkinson's Disease

BACKGROUND

Cognitive impairment is frequent in Parkinson's disease (PD) and several neurotransmitter changes have been reported since the time of diagnosis, although seldom investigated altogether in the same patient cohort.

OBJECTIVE

Our aim was to evaluate the association between neurotransmitter impairment, brain metabolism, and cognition in a cohort of de novo, drug-naïve PD patients.

METHODS

We retrospectively selected 95 consecutive drug-naïve PD patients (mean age 71.89±7.53) undergoing at the time of diagnosis a brain [18F]FDG-PET as a marker of brain glucose metabolism and proxy measure of neurodegeneration, [123I]FP-CIT-SPECT as a marker and dopaminergic deafferentation in the striatum and frontal cortex, as well as a marker of serotonergic deafferentation in the thalamus, and quantitative electroencephalography (qEEG) as an indirect measure of cholinergic deafferentation. Patients also underwent a complete neuropsychological battery.

RESULTS

Positive correlations were observed between (i) executive functions and left cerebellar cortex metabolism, (ii) prefrontal dopaminergic tone and working memory (r = 0.304, p = 0.003), (iii) qEEG slowing in the posterior leads and both memory (r = 0.299, p = 0.004) and visuo-spatial functions (r = 0.357, p < 0.001).

CONCLUSIONS

In subjects with PD, the impact of regional metabolism and diffuse projection systems degeneration differs across cognitive domains. These findings suggest possible tailored approaches to the treatment of cognitive deficits in PD.

Prevalence of Advanced Parkinson's Disease in Patients Treated in the Hospitals of the Spanish National Healthcare System: The PARADISE Study

Background: Advanced Parkinson’s disease (APD) has been recently defined as a stage in which certain symptoms and complications are present, with a detrimental influence on the overall patient’s health conditions and with a poor response to conventional treatments. However, historically, the term APD has been controversial, thus consequently, APD prevalence has not been previously studied. Objectives: The main objective was to determine the prevalence of APD in patients diagnosed with idiopathic PD in hospitals of the Spanish National Healthcare System. Secondary objectives were the prevalence and incidence of PD and the clinical and sociodemographic characteristics and quality of life of patients with APD or non-APD. Methods: This was a non-interventional, cross-sectional, multicenter, national study in the hospital setting. Results: The study population included 929 patients with PD (mean age 71.8 ± 10.1 years; 53.8% male) and a mean time since diagnosis of 6.6 ± 5.4 years. At the time of diagnosis, 613 patients (66.06%) reported having had premotor symptoms. The Hoehn and Yahr stage was 1 in 15.7% of the patients, 2 in 42.8%, 3 in 30.1%, 4 in 9.9%, and 5 in 1.4%; 46.9% of the patients had comorbidities (mean age-adjusted Charlson comorbidity index 3.5 ± 1.7; median 10-year survival 77%) and the mean 8-item Parkinson’s Disease Quality of Life Questionnaire was 27.8 ± 20.5. We found an APD prevalence of 38.21% (95%CI: 35.08–41.42%), a PD prevalence of 118.4 (95%CI: 117.3–119.6), and a PD incidence of 9.4 (95%CI: 5.42–13.4) all per 100,000 population. Among the APD population, a 15.2% were receiving some form of therapy for advanced stages of the disease (deep brain stimulation, levodopa/carbidopa intestinal gel, or apomorphine subcutaneous infusion). Conclusions: The percentage of patients with APD in the hospitals of the Spanish National Healthcare System was 38.2%.

iPSC-Derived Microglia as a Model to Study Inflammation in Idiopathic Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disease with unknown cause in the majority of patients, who are therefore considered "idiopathic" (IPD). PD predominantly affects dopaminergic neurons in the substantia nigra pars compacta (SNpc), yet the pathology is not limited to this cell type. Advancing age is considered the main risk factor for the development of IPD and greatly influences the function of microglia, the immune cells of the brain. With increasing age, microglia become dysfunctional and release pro-inflammatory factors into the extracellular space, which promote neuronal cell death. Accordingly, neuroinflammation has also been described as a feature of PD. So far, studies exploring inflammatory pathways in IPD patient samples have primarily focused on blood-derived immune cells or brain sections, but rarely investigated patient microglia in vitro. Accordingly, we decided to explore the contribution of microglia to IPD in a comparative manner using, both, iPSC-derived cultures and postmortem tissue. Our meta-analysis of published RNAseq datasets indicated an upregulation of IL10 and IL1B in nigral tissue from IPD patients. We observed increased expression levels of these cytokines in microglia compared to neurons using our single-cell midbrain atlas. Moreover, IL10 and IL1B were upregulated in IPD compared to control microglia. Next, to validate these findings in vitro, we generated IPD patient microglia from iPSCs using an established differentiation protocol. IPD microglia were more readily primed as indicated by elevated IL1B and IL10 gene expression and higher mRNA and protein levels of NLRP3 after LPS treatment. In addition, IPD microglia had higher phagocytic capacity under basal conditions-a phenotype that was further exacerbated upon stimulation with LPS, suggesting an aberrant microglial function. Our results demonstrate the significance of microglia as the key player in the neuroinflammation process in IPD. While our study highlights the importance of microglia-mediated inflammatory signaling in IPD, further investigations will be needed to explore particular disease mechanisms in these cells.

Effects of a Highly Challenging Balance Training Program on Motor Function and Brain Structure in Parkinson's Disease

Background:

Parkinson’s disease (PD) is characterized by motor deficits and brain alterations having a detrimental impact on balance, gait, and cognition. Intensive physical exercise can induce changes in the neural system, potentially counteracting neurodegeneration in PD and improving clinical symptoms.

Objective:

This randomized controlled trial investigated effects of a highly challenging, cognitively demanding, balance and gait training (HiBalance) program in participants with PD on brain structure.

Methods:

95 participants were assigned to either the HiBalance or an active control speech training program. The group-based interventions were performed in 1-hour sessions, twice per week over a 10-week period. Participants underwent balance, gait, cognitive function, and structural magnetic resonance imaging assessments before and after the interventions. Voxel-based morphometry was analyzed in 34 HiBalance and 31 active controls. Additionally, structural covariance networks were assessed.

Results:

There was no significant time by group interaction between the HiBalance and control training in balance, gait, or brain volume. Within-HiBalance-group analyses showed higher left putamen volumes post-training. In repeated measures correlation a positive linear, non-significant relationship between gait speed and putamen volume was revealed. In the HiBalance group we found community structure changes and stronger thalamic-cerebellar connectivity in structural covariance networks. Neither brain volume changes nor topology changes were found for the active controls after the training.

Conclusion:

Thus, subtle structural brain changes occur after balance and gait training. Future studies need to determine whether training modifications or other assessment methods lead to stronger effects.

Using complexity-entropy planes to detect Parkinson's disease from short segments of haemodynamic signals

Objective. There is emerging evidence that analysing the entropy and complexity of biomedical signals can detect underlying changes in physiology which may be reflective of disease pathology. This approach can be used even when only short recordings of biomedical signals are available. This study aimed to determine whether entropy and complexity measures can detect differences between subjects with Parkinsons disease and healthy controls (HCs).Approach. A method based on a diagram of entropy versus complexity, named complexity-entropy plane, was used to re-analyse a dataset of cerebral haemodynamic signals from subjects with Parkinsons disease and HCs obtained under poikilocapnic conditions. A probability distribution for a set of ordinal patterns, designed to capture regularities in a time series, was computed from each signal under analysis. Four types of entropy and ten types of complexity measures were estimated from these distributions. Mean values of entropy and complexity were compared and their classification power was assessed by evaluating the best linear separator on the corresponding complexity-entropy planes.Main results. Few linear separators obtained significantly better classification, evaluated as the area under the receiver operating characteristic curve, than signal mean values. However, significant differences in both entropy and complexity were detected between the groups of participants.Significance. Measures of entropy and complexity were able to detect differences between healthy volunteers and subjects with Parkinson's disease, in poikilocapnic conditions, even though only short recordings were available for analysis. Further work is needed to refine this promising approach, and to help understand the findings in the context of specific pathophysiological changes.

MRI-Based Radiomics of Basal Nuclei in Differentiating Idiopathic Parkinson's Disease From Parkinsonian Variants of Multiple System Atrophy: A Susceptibility-Weighted Imaging Study

Objectives

To investigate the value of MRI-based radiomic model based on the radiomic features of different basal nuclei in differentiating idiopathic Parkinson's disease (IPD) from Parkinsonian variants of multiple system atrophy (MSA-P).

Methods

Radiomics was applied to the 3T susceptibility- weighted imaging (SWI) from 102 MSA-P patients and 83 IPD patients (allocated to a training and a testing cohort, 7:3 ratio). The substantia nigra (SN), caudate nucleus (CN), putamen (PUT), globus pallidus (GP), red nucleus (RN), and subthalamic nucleus (STN) were manually segmented, and 396 features were extracted. After feature selection, support vector machine (SVM) was generated, and its predictive performance was calculated in both the training and testing cohorts using the area under receiver operating characteristic curve (AUC).

Results

Seven radiomic features were selected from the PUT, by which the SVM classifier achieved the best diagnostic performance with an AUC of 0.867 in the training cohort and an AUC of 0.862 in the testing cohort. Furthermore, the combined model, which incorporating part III of the Parkinson's Disease Rating Scale (UPDRSIII) scores into radiomic features of the PUT, further improved the diagnostic performance. However, radiomic features extracted from RN, SN, GP, CN, and STN had moderate to poor diagnostic performance, with AUC values that ranged from 0.610 to 0.788 in the training cohort and 0.583 to 0.766 in the testing cohort.

Conclusion

Radiomic features derived from the PUT had optimal value in differentiating IPD from MSA-P. A combined radiomic model, which contained radiomic features of the PUT and UPDRSIII scores, further improved performance and may represent a promising tool for distinguishing between IPD and MSA-P.

Working memory training increases neural efficiency in Parkinson's disease: a randomized controlled trial

Impairment of working memory and executive functions is already frequently observed in early stages of Parkinson's disease. Improvements in working memory performance in this cohort could potentially be achieved via working memory training. However, the specific neural mechanisms underlying different working memory processes such as maintenance as opposed to manipulation are largely under-investigated in Parkinson's disease. Moreover, the plasticity of these correlates as a function of working memory training is currently unknown in this population. Thus, the working memory subprocesses of maintenance and manipulation were assessed in 41 cognitively healthy patients with Parkinson's disease using a newly developed working memory paradigm and functional MRI. Nineteen patients were randomized to a 5-week home-based digital working memory training intervention while the remaining patients entered a control, wait list condition. Working memory task-related activation patterns and context-dependent functional connectivity, as well as the change of these neural correlates as a function of training, were assessed. While both working memory processes activated an extended frontoparietal-cerebellar network, only the manipulation of items within working memory also recruited the anterior striatum. The intervention effect on the neural correlates was small, but decreased activation in areas relevant for working memory could be observed, with activation changes correlating with behavioural change. Moreover, training seemed to result in decreased functional connectivity when pure maintenance was required, and in a reorganization of functional connectivity when items had to be manipulated. In accordance with the neural efficacy hypothesis, training resulted in overall reduced activation and reorganized functional connectivity, with a differential effect on the different working memory processes under investigation. Now, larger trials including follow-up examinations are needed to further explore the long-term effects of such interventions on a neural level and to estimate the clinical relevance to potentially delay cognitive decline in cognitively healthy patients with Parkinson's disease.

Elevated Plasma microRNA-105-5p Level in Patients With Idiopathic Parkinson's Disease: A Potential Disease Biomarker

Parkinson's disease (PD) is the second most common neurodegenerative disease, which still lacks a biomarker to aid in diagnosis and to differentiate diagnosis at the early stage of the disease. microRNAs (miRNAs) are small and evolutionary conserved non-coding RNAs that are involved in post-transcriptional gene regulation. Several miRNAs have been proposed as potential biomarkers in several diseases. In the present study, we screened miRNAs using a network vulnerability analysis, to evaluate their potential as PD biomarkers. We first extracted miRNAs that were differentially expressed between PD and healthy controls (HC) samples. Then we constructed the PD-specific miRNA-mRNA network and screened miRNA biomarkers using a new bioinformatics model. With this model, we identified miR-105-5p as a putative biomarker for PD. Moreover, we measured miR-105-5p levels in the plasma of patients with idiopathic PD (IPD) (n = 319), neurological disease controls (NDC, n = 305) and HC (n = 273) using reverse transcription real-time quantitative PCR (RT-qPCR). Our data clearly demonstrated that the plasma miR-105-5p level in IPD patients was significantly higher than those of HC (251%, p < 0.001) and NDC (347%, p < 0.001). There was no significant difference in miR-105-5p expression between IPD patients with or without anti-PD medications. Interestingly, we found that the plasma miR-105-5p expression level may be able to differentiate IPD from parkinsonian syndrome, essential tremor and other neurodegenerative diseases. We believe that a change in the plasma miR-105-5p level is a potential biomarker for IPD.

Complementary and Alternative Medicine for Idiopathic Parkinson's Disease: An Evidence-Based Clinical Practice Guideline

Patients with idiopathic Parkinson's disease (IPD) require long-term care and are reported to use complementary and alternative medicine (CAM) interventions frequently. This CAM-specific clinical practice guideline (CPG) makes recommendations for the use of CAM, including herbal medicines, acupuncture, moxibustion, pharmaco-acupuncture, and qigong (with Tai chi) in patients with IPD. This guideline was developed using an evidence-based approach with randomized controlled trials currently available. Even though this CPG had some limitations, mainly originating from the bias inherent in the research on which it is based, it would be helpful when assessing the value of the CAM interventions frequently used in patients with IPD.

Distribution of non-motor symptoms in idiopathic Parkinson's disease and secondary Parkinsonism

Background

Non-motor symptoms (NMS) are frequent in patients with idiopathic Parkinson’s disease (IPD). Clinical expressions, postulated pathophysiological mechanisms, and responsiveness to antiparkinson medication represent differences between IPD and secondary Parkinsonism (SP).

Objective

To evaluate NMS expressions in IPD, SP, and a matched control group.

Methods

The accepted criteria for IPD and SP were controlled for the participants who were consecutively recruited at two outdoor patient clinics. The Well-Being Map™ was used as the evaluation instrument. These were completed by the participants before their visit. The controls consisted of non-Parkinsonian individuals who were matched by age and gender.

Results

A total of 185 participants participated in the study, IPD/SP/controls; n=73/53 and 59, respectively. The mean age was 74 years, and the median duration of disease was 6/3 years. Differences were shown between the combined IPD/SP groups and the controls. Limited differences between the IPD and SP groups could be demonstrated. Symptoms such as pain, decreased taste, as well as sleep and bladder disturbances were more frequent in the IPD group. When more than minor problems with moving were reported, disturbances in sleep and digestion were also noted to a large extent.

Conclusion

Despite differences in the pathophysiological mechanisms between IPD and SP, the study showed only minor differences in the expression of NMS. IPD and SP reported statistically more significant problems in all items compared to the controls. Sleeping problems were strongly associated with symptoms from the gastrointestinal tract, but sleep was only affected by longer disease duration to a minor extent. Motor symptoms, such as morning stiffness, were common in all three groups. Neurodegenerative diseases might have more complex expressions in common than what we have known before and it is certainly not a part of normal aging.

Assessment of mental health of carers according to patient stage of idiopathic Parkinson's disease

Background and purpose

In this study the aim was to collect data to assess the mental health of carers for patients with diagnosis of idiopathic Parkinson's disease (IPD) according to disease stage and to examine precautions to reduce the patient and disease load on carers.

Methods

The study included 144 patients with staging according to modified Hoehn and Yahr criteria and 144 patient relatives who provided care support for patients every day, for some or all of the day, and who were over the age of 18 years and accepted participation in the research. Our prospective and cross-sectional study performed detailed neurological examination of patients, and after completing the 'Personal Information Form' with the interviewer every patient, with idiopathic Parkinson's disease (IPD) according to 'UK Brain Bank' diagnostic criteria, had the 'Unified Parkinson's Disease Rating Scale (UPDRS)' and 'Modified Hoehn and Yahr scale (HYS)' applied. Carers first completed the 'Personal Information Form' and then had the 'Short Symptom Inventory (SSI)' applied.

Results

As the stage of disease increased, the points for all sub-scales of the Short Symptom Inventory increased.

Conclusion

With the parallel increase in disease scores and UPDRS stage scores, the points obtained by carers on the SSI sub-scales increased. This data shows that with progressing disease stage, the load on the carer increases and mental health begins to be disrupted.

Postural Stabilization Differences in Idiopathic Parkinson's Disease and Progressive Supranuclear Palsy during Self-Triggered Fast Forward Weight Lifting

Progressive supranuclear palsy (PSP) and late-stage idiopathic Parkinson’s disease (IPD) are neurodegenerative movement disorders resulting in different postural instability and falling symptoms. IPD falls occur usually forward in late stage, whereas PSP falls happen in early stages, mostly backward, unprovoked, and with high morbidity. Self-triggered, weighted movements appear to provoke falls in IPD, but not in PSP. Repeated self-triggered lifting of a 0.5–1-kg weight (<2% of body weight) with the dominant hand was performed in 17 PSP, 15 IPD with falling history, and 16 controls on a posturography platform. PSP showed excessive force scaling of weight and body motion with high-frequency multiaxial body sway, whereas IPD presented a delayed-onset forward body displacement. Differences in center of mass displacement apparent at very small weights indicate that both syndromes decompensate postural control already within stability limits. PSP may be subject to specific postural system devolution. IPD are susceptible to delayed forward falling. Differential physiotherapy strategies are suggested.

Neck Vibration Proprioceptive Postural Response Intact in Progressive Supranuclear Palsy unlike Idiopathic Parkinson's Disease

Progressive supranuclear palsy (PSP) and late-stage idiopathic Parkinson’s disease (IPD) are neurodegenerative movement disorders resulting in different postural instability and falling symptoms. IPD falls occur usually forward in late stage, whereas PSP falls happen in early stages, mostly backward, unprovoked, and with high morbidity. Postural responses to sensory anteroposterior tilt illusion by bilateral dorsal neck vibration were probed in both groups versus healthy controls on a static recording posture platform. Three distinct anteroposterior body mass excursion peaks (P1–P3) were observed. 18 IPD subjects exhibited well-known excessive response amplitudes, whereas 21 PSP subjects’ responses remained unaltered to 22 control subjects. Neither IPD nor PSP showed response latency deficits, despite brainstem degeneration especially in PSP. The observed response patterns suggest that PSP brainstem pathology might spare the involved proprioceptive pathways and implies viability of neck vibration for possible biofeedback and augmentation therapy in PSP postural instability.

Whole-Brain Atrophy Differences between Progressive Supranuclear Palsy and Idiopathic Parkinson's Disease

Background: The absence of markers for ante-mortem diagnosis of progressive supranuclear palsy (PSP), results in this disorder being commonly mistaken for other conditions, such as idiopathic Parkinson’s disease (IPD). Such mistakes occur particularly in the initial stages, when “plus syndrome” has not yet clinically emerged.

Objective: To investigate the global brain volume and tissue loss in patients with PSP relative to patients with IPD and healthy controls and correlations between clinical parameters and magnetic resonance imaging (MRI)-derived brain volume estimates.

Methods: T1-weighted images were obtained from three groups of Chilean Latin American adults: 21 patients with IPD, 18 patients with PSP and 14 healthy controls. We used Structural Imaging Evaluation with Normalization of Atrophy (SIENAX) to assess white matter, gray matter and whole-brain volumes (normalized to cranial volume). Imaging data were used to analyze putative correlations with the clinical status of PSP and IPD patients using the Unified Parkinson’s Disease Rating Scale Part III (UPDRS III), Hoehn and Yahr (H&Y), the Clinical Global Impression for Disease Severity Scale (CGI-S) and the Frontal Assessment Battery (FAB).

Results: PSP patients had significantly lower whole brain volume than both IPD patients and controls. Whole brain volume reduction in PSP patients was primarily attributable to gray matter volume reduction. We found a significant correlation between brain volume reduction and clinical status in the PSP group.

Conclusions: At the group level, the whole brain and gray matter volumes differentiated patients with PSP from patients with IPD. There was also significant clinical-imaging correlations with motor disturbances in PSP.

A Visual Rating Scale for the Hummingbird Sign with Adjustable Diagnostic Validity

BACKGROUND

Although the hummingbird sign (HBS) is a distinctive feature of progressive supranuclear palsy (PSP) VS. idiopathic Parkinson's disease (IPD) and other parkinsonian disorders, there are no consensus criteria for its identification.

OBJECTIVE

To develop consensus criteria for the HBS to enable accurate communication between researchers and physicians, we developed a new radiologic rating scale for the HBS (the HBS-RS), and the inter-rater reliability (IRR) and diagnostic validity of the HBS-RS were evaluated.

METHODS

Two raters blinded to the clinical diagnoses reviewed T1 midsagittal magnetic resonance images of 133 patients with IPD (n = 93) or PSP (n = 40). The existence of the HBS was assessed in two steps that were separated by two weeks; the first was based on their own experience and the second was according to the HBS-RS. The HBS-RS comprises 4 items (contour of the third ventricle floor, shape of the beak, shape of the hummingbird head, and midbrain atrophy), with weighted scores from 0 to 2.

RESULTS

The IRR of individual items in the HBS-RS and of the composite scores showed moderate-to-good agreement (Cohen's kappa [κ], 0.479-0.766) and were observed to be highest for the contour of the third ventricle floor. The sensitivities and specificities varied depending on the cut-off for each item or for the composite scores. The sensitivities for each item were high (85.0-92.5) at a low cut-off (0 VS. 1 or 2). The specificities reached more than 80% when the composite scores of the HBS-RS were used. Receiver operating characteristic curves for the total HBS-RS scores showed fair diagnostic accuracy for PSP (AUC, 0.76 and 0.73).

CONCLUSIONS

The HBS-RS is a simple and measurable visual assessment tool to identify the HBS, with adjustable diagnostic validity for PSP. The results suggest that the HBS-RS may be used for objective measurements of the HBS in research and in the clinic.

LC-MS-based urinary metabolite signatures in idiopathic Parkinson's disease

Increasing evidence has shown that abnormal metabolic phenotypes in body fluids reflect the pathogenesis and pathophysiology of Parkinson's disease (PD). These body fluids include urine; however, the relationship between, specifically, urinary metabolic phenotypes and PD is not fully understood. In this study, urinary metabolites from a total of 401 clinical urine samples collected from 106 idiopathic PD patients and 104 normal control subjects were profiled by using high-performance liquid chromatography coupled to high-resolution mass spectrometry. Our study revealed significant correlation between clinical phenotype and urinary metabolite profile. Metabolic profiles of idiopathic PD patients differed significantly and consistently from normal controls, with related metabolic pathway variations observed in steroidogenesis, fatty acid beta-oxidation, histidine metabolism, phenylalanine metabolism, tryptophan metabolism, nucleotide metabolism, and tyrosine metabolism. In the fruit fly Drosophila melanogaster, the alteration of the kynurenine pathway in tryptophan metabolism corresponded with pathogenic changes in the alpha-synuclein overexpressed Drosophila model of PD. The results suggest that LC-MS-based urinary metabolomic profiling can reveal the metabolite signatures and related variations in metabolic pathways that characterize PD. Consistent PD-related changes across species may provide the basis for understanding metabolic regulation of PD at the molecular level.

Kinematics of the Reach-to-Grasp Movement in Vascular Parkinsonism: A Comparison with Idiopathic Parkinson's Disease Patients

The performance of patients with vascular parkinsonism (VPD) on a reach-to-grasp task was compared with that of patients affected by idiopathic Parkinson’s disease (IPD) and age-matched control subjects. The aim of the study was to determine how patients with VPD and IPD compare at the level of the kinematic organization of prehensile actions. We examined how subjects concurrently executed the transport and grasp components of reach-to-grasp movements when grasping differently sized objects. When comparing both VPD and IPD groups to control subjects, all patients showed longer movement duration and smaller hand opening, reflecting bradykinesia and hypometria, respectively. Furthermore, for all patients, the onset of the manipulation component was delayed with respect to the onset of the transport component. However, for patients with VPD this delay was significantly smaller than that found for the IPD group. It is proposed that this reflects a deficit – which is moderate for VPD as compared to IPD patients – in the simultaneous (or sequential) implementation of different segments of a complex movement. Altogether these findings suggest that kinematic analysis of reach-to-grasp movement has the ability to provide potential instruments to characterize different forms of parkinsonism.

Hypokinesia upon Pallidal Deep Brain Stimulation of Dystonia: Support of a GABAergic Mechanism

In the past, many studies have documented the beneficial effects of deep brain stimulation (DBS) in the globus pallidus internus for treatment of primary segmental or generalized dystonia. Recently however, several reports focused on DBS-induced hypokinesia or freezing of gait (FOG) as a side effect in these patients. Here we report on two patients suffering from FOG after successful treatment of their dystonic movement disorder with pallidal high frequency stimulation (HFS). Several attempts to reduce the FOG resulted in worsening of the control of dystonia. In one patient levodopa treatment was initialized which was somewhat successful to relieve FOG. We discuss the possible mechanisms of hypokinetic side effects of pallidal DBS which can be explained by the hypothesis of selective GABA release as the mode of action of HFS. Pallidal HFS is also effective in treating idiopathic Parkinson’s disease as a hypokinetic disorder which at first sight seems to be a paradox. In our view, however, the GABAergic hypothesis can explain this and other clinical observations.