A formula for the conversion of UPDRS-III scores to Hoehn and Yahr stage

Computerized Simple Reaction Time and Balance in Nondemented Parkinson's Patients

BACKGROUND

Parkinson's disease (PD) patients are known to suffer from subtle cognitive and balance deficits from the early stages although they usually manifest in advanced stages. Postural instability (PI) has been correlated with slower information processing speed. Simple reaction time (SRT) tasks can be used to measure the speed of information processing. The main objective of this study was to examine the usefulness of SRT as a valid predictor of balance in PD, thus providing a simple and complementary assessment method.

METHODS

This cross-sectional study included 52 PD patients without dementia who were evaluated for balance using the pull test (PT) maneuver and Biodex® limits of stability (LOS). In addition, a reaction time task was used to measure processing speed. Correlation and linear regression analyses were performed.

RESULTS

The performance of SRT tasks was correlated with the evaluation of LOS% and PT, suggesting that the SRT may be a predictor of balance performance. Longer reaction time and poorer postural stability were also associated with disease duration but not with age.

CONCLUSIONS

Poor performance in a simple reaction task can predict altered PI and can complement staging and evaluation in PD patients.

Binary dance rhythm or Quaternary dance rhythm which has the greatest effect on non-motor symptoms of individuals with Parkinson's disease?

This study aimed to compare the effect of a binary and quaternary rhythm protocol on cognition, mental activity, daily life, and quality of life among individuals with Parkinson's Disease. A two-arm randomized clinical trial with 31 individuals diagnosed with Parkinson's disease, who were allocated to the binary group or quaternary group. Both groups underwent a 12-week intervention. The following variables were analyzed: personal and clinical information; MoCA; UPDRSI and II; PDQ-39. Both intervention groups improved cognition, mental activity, activities of daily living, and quality of life. In addition, there were intergroup differences in total UPDRSII, writing, and hygiene where the quaternary group was superior to the binary group. It concludes that the binary and quaternary rhythm positively influenced and presented similar effects on the complementary treatment of individuals with Parkinson's disease on the studied variables. Thus, it is believed that both interventions are possible and feasible for the health professionals involved in the area.

Freezing of gait detection in Parkinson's disease via multimodal analysis of EEG and accelerometer signals

Parkinson's disease (PD) patients with freezing of gait (FOG) can suddenly lose their forward moving ability leading to unexpected falls. To overcome FOG and avoid the falls, a real-time accurate FOG detection or prediction system is desirable to trigger on-demand cues. In this study, we designed and implemented an in-place movement experiment for PD patients to provoke FOG and meanwhile acquired multimodal physiological signals, such as electroencephalography (EEG) and accelerometer signals. A multimodal model using brain activity from EEG and motion data from accelerometers was developed to improve FOG detection performance. In the detection of over 700 FOG episodes observed in the experiments, the multimodal model achieved 0.211 measured by Matthews Correlation Coefficient (MCC) compared with the single-modal models (0.127 or 0.139).Clinical Relevance- This is the first study to use multimodal: EEG and accelerometer signal analysis in FOG detection, and an improvement was achieved.

Identification of distinct blood-based biomarkers in early stage of Parkinson's disease

Parkinson's disease (PD) is a slowly progressive geriatric disease, which can be one of the leading causes of serious socioeconomic burden in the aging society. Clinical trials suggest that prompt treatment of early-stage Parkinson's disease (EPD) may slow down the disease progress and have a better response. Therefore, conducting proteomics study to identify biomarkers for the diagnosis and disease-modifying therapies of EPD is vital. We aimed at identifying distinct protein autoantibody biomarkers of EPD by using the database of GSE62283 based on the platform GPL13669 downloaded from Gene Expression Omnibus database. Differentially expressed proteins (DEPs) between the EPD group (n = 103) and the normal control (NC) group (n = 111) were identified by protein-specific t test. Cluster analysis of DEPs was conducted by protein-protein interaction network to detect hub proteins. The hub proteins were then evaluated to determine the distinct biomarkers by principal component analysis, as well as functional and pathway enrichment analysis. Their biological functions were confirmed by gene ontology functional (GO) and Kyoto encyclopedia of genes and genomes pathway enrichment (KEGG). Two biomarkers, mitochondrial ribosome recycling factor (MRRF) and ribosomal protein S18 (RPS18), distinguished the EPD samples from the NC samples, and they were regarded as high-confidence distinct protein autoantibody biomarkers of EPD. The most significant GO function was protein serine/threonine kinase activity (GO: 0004674) and most of DEPs were enriched in ATP binding in molecular function category (GO: 0005524). These results may help in establishing the prompt and accurate diagnosis of EPD and may also contribute to develop mechanism-based treatments.

Early detection of Parkinson's disease through patient questionnaire and predictive modelling

Early detection of Parkinson's disease (PD) is important which can enable early initiation of therapeutic interventions and management strategies. However, methods for early detection still remain an unmet clinical need in PD. In this study, we use the Patient Questionnaire (PQ) portion from the widely used Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) to develop prediction models that can classify early PD from healthy normal using machine learning techniques that are becoming popular in biomedicine: logistic regression, random forests, boosted trees and support vector machine (SVM). We carried out both subject-wise and record-wise validation for evaluating the machine learning techniques. We observe that these techniques perform with high accuracy and high area under the ROC curve (both >95%) in classifying early PD from healthy normal. The logistic model demonstrated statistically significant fit to the data indicating its usefulness as a predictive model. It is inferred that these prediction models have the potential to aid clinicians in the diagnostic process by joining the items of a questionnaire through machine learning.

The Hawthorne effect as a pre-placebo expectation in Parkinsons disease patients participating in a randomized placebo-controlled clinical study

BACKGROUND

The Hawthorne effect on clinical studies in Parkinson's disease has not been thoroughly investigated. Evidently the Hawthorne effect may have impact on study outcomes acting as a 'pre-placebo' effect in the recruitment phase, hence before inclusion.

AIM

The aim of this study was to discuss the Hawthorne effect in relation to clinical and self-reported outcome measures in a randomized clinical study in the recruitment phase and during the study.

METHODS

Data from 97 participants with Parkinson's disease treated with Transcranial Pulsed Electromagnetic Fields were applied, randomized to an active (n = 49) or a placebo treated group (n = 48). The participants received one home treatment session, for eight consecutive weeks. Outcome measures were the Unified Parkinson's Disease Rating Scale, The 39-item Parkinson's Disease Questionnaire and the WHO-5.

RESULTS

No difference in treatment effect between the two groups was found pertaining the Unified Parkinson's Disease Rating Scale. No difference in treatment effect between the two groups was found pertaining the 39-item Parkinson's Disease Questionnaire, apart from the dimension mobility. No difference in treatment effect between the two groups was found pertaining the WHO-5 scale.

CONCLUSIONS

The Hawthorne effect may have caused a 'pre-placebo' effect on the outcome measures even before obtaining baseline outcomes measures. This study may have been particularly prone to a Hawthorne effect due to the intense contact with the participants before and during the study. Moreover, the Hawthorne effect should not be viewed upon as a single entity but rather as entities affecting outcome measures throughout the full study period.

Impact of the LSVT on vowel articulation and coarticulation in Parkinson's disease

The purpose of this study was to investigate the impact of the Lee Silverman Voice Treatment (LSVT®) on vowel articulation and consonant-vowel (C-V) coarticulation in dysarthric speakers with Parkinson's disease (PD). Nine Quebec French speakers diagnosed with idiopathic PD underwent the LSVT®. Speech characteristics were compared before and after treatment. Vowel articulation was measured using acoustic vowel space and calculated with the first (F1) and second formant (F2) of the vowels /i/, /u/ and /a/. C-V coarticulation was measured using locus equations, an acoustic metric based on the F2 transitions within vowels in relation to the preceding consonant. The relationship between these variables, speech loudness and vowel duration was also analysed. Results showed that vowel contrast increased in F1/F2 acoustic space after administration of the LSVT®. This improvement was associated with the gain in speech loudness and longer vowel duration. C-V coarticulation patterns between consonant contexts showed greater distinctiveness after the treatment. This improvement was associated with the gain in speech loudness only. These results support the conclusions of previous studies investigating the relationship between the LSVT®, speech loudness and articulation in PD. These results expand clinical understanding of the treatment and indicate that loud speech changes C-V coarticulation patterns. Clinical applications and theoretical considerations are discussed.

Changes in vowel articulation with subthalamic nucleus deep brain stimulation in dysarthric speakers with Parkinson's disease

Purpose. To investigate changes in vowel articulation with the electrical deep brain stimulation (DBS) of the subthalamic nucleus (STN) in dysarthric speakers with Parkinson's disease (PD). Methods. Eight Quebec-French speakers diagnosed with idiopathic PD who had undergone STN DBS were evaluated ON-stimulation and OFF-stimulation (1 hour after DBS was turned off). Vowel articulation was compared ON-simulation versus OFF-stimulation using acoustic vowel space and formant centralization ratio, calculated with the first (F1) and second formant (F2) of the vowels /i/, /u/, and /a/. The impact of the preceding consonant context on articulation, which represents a measure of coarticulation, was also analyzed as a function of the stimulation state. Results. Maximum vowel articulation increased during ON-stimulation. Analyses also indicate that vowel articulation was modulated by the consonant context but this relationship did not change with STN DBS. Conclusions. Results suggest that STN DBS may improve articulation in dysarthric speakers with PD, in terms of range of movement. Optimization of the electrical parameters for each patient is important and may lead to improvement in speech fine motor control. However, the impact on overall speech intelligibility may still be small. Clinical considerations are discussed and new research avenues are suggested.

Web-based assessment of visual and visuospatial symptoms in Parkinson's disease

Visual and visuospatial dysfunction is prevalent in Parkinson's disease (PD). To promote assessment of these often overlooked symptoms, we adapted the PD Vision Questionnaire for Internet administration. The questionnaire evaluates visual and visuospatial symptoms, impairments in activities of daily living (ADLs), and motor symptoms. PD participants of mild to moderate motor severity (n = 24) and healthy control participants (HC, n = 23) completed the questionnaire in paper and web-based formats. Reliability was assessed by comparing responses across formats. Construct validity was evaluated by reference to performance on measures of vision, visuospatial cognition, ADLs, and motor symptoms. The web-based format showed excellent reliability with respect to the paper format for both groups (all P′s < 0.001; HC completing the visual and visuospatial section only). Demonstrating the construct validity of the web-based questionnaire, self-rated ADL and visual and visuospatial functioning were significantly associated with performance on objective measures of these abilities (all P′s < 0.01). The findings indicate that web-based administration may be a reliable and valid method of assessing visual and visuospatial and ADL functioning in PD.

Effect of step training and rhythmic auditory stimulation on functional performance in Parkinson patients

BACKGROUND

Rhythmic auditory stimulation (RAS) can influence movement during straight line walking and direction transition in individuals with Parkinson disease (PD).

OBJECTIVE

The authors studied whether multidirectional step training with RAS would generalize to functional gait conditions used in daily activities and balance.

METHODS

In a matched-pairs design, 8 patients practiced externally paced (EP) stepping (RAS group), and 8 patients practiced internally paced (IP) stepping (no RAS group) for 6 weeks. Participants were evaluated on the first and last days of practice, and 1 week, 4 weeks, and 8 weeks after practice termination. Evaluations included a primary measurement--the Dynamic Gait Index (DGI)--and secondary measurements--the Unified Parkinson's Disease Rating Scale (UPDRS), Tinetti-gait and balance tests, Timed-Up-and-Go (TUG), and Freezing of Gait Questionnaire (FOGQ).

RESULTS

The RAS group significantly improved performance on the DGI and several secondary measures, and they maintained improvements for the DGI, Tinetti, FOGQ, and balance and gait items of the UPDRS above pretraining values at least 4 weeks after practice termination. The no RAS group revealed several improvements with training but could not maintain these improvements for as long as the other group.

CONCLUSIONS

Individuals with PD can generalize motor improvements achieved during multidirectional step training to contexts of functional gait and balance. Training with RAS is advantageous for enhancing functional gait improvements and the maintenance of functional gait and balance improvements over 8 weeks.

White matter microstructure changes in the thalamus in Parkinson disease with depression: A diffusion tensor MR imaging study

BACKGROUND AND PURPOSE

Depression occurs frequently in PD; however the neural basis of depression in PD remains unclear. The aim of this study was to characterize possible depression-related white matter microstructural changes in the thalamus of patients with DPD compared with those with NDPD.

MATERIALS AND METHODS

FA and MD maps from DTI were obtained in 14 patients with DPD and 18 patients with NDPD. Region-of-interest-guided VBA was conducted on the FA maps to detect possible microstructural differences in the thalamus between these 2 patient groups. Moreover, mean FA and MD in regions with a detected difference were compared between DPD and NDPD groups, and correlations between diffusion quantities and the severity of depression were analyzed.

RESULTS

White matter microstructure differences were found between the patients with DPD and NDPD in the bilateral mediodorsal thalamic regions. In these regions, patients with DPD showed significantly decreased FA values (P < .005) compared with patients with NDPD, and the mean values of FA were negatively correlated with the scores of depression severity (P < .05) for patients with PD. No significant differences of MD were found in the mediodorsal thalamus between these 2 groups.

CONCLUSIONS

Our results provide preliminary evidence that the mediodorsal thalamus may play an important role in depression in PD and suggest a relationship between FA in the mediodorsal thalamus and the presence of depressive symptoms in patients with DPD. These findings may be helpful for further understanding the potential mechanisms of depression in PD.