Parkinson Disease Rating Scale Motor Research Articles

Virtual Reality-Based Assessment for Rehabilitation of the Upper Limb in Patients with Parkinson's Disease: A Pilot Cross-Sectional Study.

Background and Objectives: This study aimed to examine the responsiveness and concurrent validity of a serious game and its correlation between the use of serious games and upper limbs (UL) performance in Parkinson's Disease (PD) patients. Materials and Methods: Twenty-four consecutive upper limbs (14 males, 8 females, age: 55-83 years) of PD patients were assessed. The clinical assessment included: the Box and Block test (BBT), Nine-Hole Peg test (9HPT), and sub-scores of the Unified Parkinson's Disease Rating-Scale Motor section (UPDRS-M) to assess UL disability. Performance scores obtained in two different tests (Ex. A and Ex. B, respectively, the Trolley test and Mushrooms test) based on leap motion (LM) sensors were used to study the correlations with clinical scores. Results: The subjective fatigue experienced during LM tests was measured by the Borg Rating of Perceived Exertion (RPE, 0-10); the BBT and 9HPT showed the highest correlation coefficients with UPDRS-M scores (ICCs: -0.652 and 0.712, p < 0.05). Exercise A (Trolley test) correlated with UPDRS-M (ICC: 0.31, p < 0.05), but not with the 9HPT and BBT tests (ICCs: -0.447 and 0.390, p < 0.05), while Exercise B (Mushroom test) correlated with UPDRS-M (ICC: -0.40, p < 0.05), as did these last two tests (ICCs: -0.225 and 0.272, p < 0.05). The mean RPE during LM tests was 3.4 ± 3.2. The evaluation of upper limb performance is feasible and does not induce relevant fatigue. Conclusions: The analysis of the ICC supports the use of Test B to evaluate UL disability and performance in PD patients, while Test A is mostly correlated with disability. Specifically designed serious games on LM can serve as a method of impairment in the PD population.

Evaluation of Substantia Nigra morphology in Parkinson's Disease.

In the elderly population, Parkinson's Disease (PD) is the second most common neurodegenerative disorder and is associated with morphological changes in the basal ganglia, especially the substantia nigra (SN). This study aimed to evaluate the volume and signal intensity (SI) of SN using Magnetic Resonance Imaging (MRI) to detect structural changes and investigate the relationship between the onset side and disease severity of PD. Clinical features and imaging data of 58 patients with PD were retrospectively analyzed from their medical records. Axial T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences of 3 Tesla (T) MRIs were used for the measurements. The right and left SN volumes and SI measurements were calculated in duplicate by 2 blinded and qualified neuroradiologists. The side of disease onset, disease duration, levodopa equivalent daily dose, Movement Disorder Society-sponsored Unified Parkinson Disease Rating Scale (MDS-UPDRS III) motor score, and modified Hoehn and Yahr (H&Y) scale scores were recorded and compared with SN volume and SI measurements. No statistically significant difference was found between the disease onset side and contralateral SN volume or SI measurements (P > .05). Despite high inter- and intra-rater reliability rates, there was no significant difference in the volume and SI of the contralateral SN according to H&Y stages (P > .05). Furthermore, SN volume and SI measurements were not significantly correlated with disease duration and MDS-UPDRS III motor score (P > .05). SN volume and SI values measured using axial FLAIR 3T MRI are not correlated with the side of onset or disease severity in PD. New imaging methods are required to detect preclinical or early-stage PD.

The effect of deep brain stimulation on lower extremity dexterity in people with Parkinson’s disease

Purpose To examine the effect of deep brain stimulation (DBS) on lower extremity dexterity in people with Parkinson’s disease (PwPD) and to investigate the relationship between this effect and the effect of DBS on measures of different walking characteristics, and other features of Parkinson’s disease. Materials and methods Thirty-six PwPD were included. Assessment was performed twice with DBS “on” and DBS “off” state. Results The LEDT scores of both extremities, the Unified Parkinson Disease Rating Scale-motor section (UPDRS-III), the 10-Meter Walk Test (TMWT), the Timed Up and Go Test (TUG), the Figure-of-Eight Walk Test (FEWT), and the Three-Meter Backward Walk Test (TMBWT) scores were significantly better in “on” DBS condition than “off” DBS condition. The effect of DBS on lower extremity dexterity is related to age and levodopa equivalent daily dosage (LEDD). The effect of DBS on lower extremity dexterity and the effect of DBS on the bradykinesia, TUG, the FEWT, and the TMBWT were also related. Conclusions DBS has a positive effect on lower extremity dexterity. Clinical characteristics such as age and LEDD and the effect of DBS on bradykinesia, walking with turning, curved walking, and backward walking is related with the effect of DBS on lower extremity dexterity.

4 An Update: Greater Apathy Associated with Selective Serotonin Reuptake Inhibitor Use in Parkinson’s Disease

Objective:Apathy is a primary lack of motivation that is frequently reported in Parkinson’s disease (PD) and often misdiagnosed as depression. In PD, apathy worsens over time with motor symptom progression. Evidence over the past 15 years has documented that use of selective serotonin reuptake inhibitors (SSRIs) is associated with increased apathy in patients with depression, including individuals with PD. In PD, this appears to be related to downregulation of dopaminergic systems by serotonin. Despite increasing evidence, SSRIs continue to be heavily prescribed in individuals with PD— potentially worsening apathy and decreasing quality of life for these individuals. This study is an update, re-examining the relationship between apathy and the use of SSRIs and other antidepressants in a large cohort of individuals with PD.Participants and Methods:Participants included a convenience sample of 387 nondemented individuals with idiopathic PD who were in their mid-60's (mean age=64.9+8.72 years), well-educated (mean=14.95+2.78 years), predominantly male (72.4%), non-Hispanic white (94.5%), and in mid-stage of disease severity (on medication Unified Parkinson Disease Rating Scale motor score=25.3+10.1). All scored above clinical cutoff for dementia on a cognitive screener (Dementia Rating Scale-2 (DRS) &gt; 125). Medications, cognitive, mood, and clinical data were extracted from chart review. Depression and apathy were measured using the Beck Depression Inventory-II (BDI-Il) and the Apathy Scale (AS). Antidepressant medications were grouped into SSRIs, serotonin and norepinephrine reuptake inhibitors (SNRIs) and other. Analyses included bootstrapped Pearson’s correlations, Pearson’s chi-square, and linear regressionsResults:Among 387 individuals with PD, 41.3% (N=160) were taking antidepressant medications. Of these 160, 61.3% were on SSRIs, 24.4% on SNRIs, and the remainder on other antidepressants. Approximately 36.9% of the 387 PD patients exceeded recommended clinical cutoffs for apathy (AS &gt;14) and 23.5% for depression (BDI-II &gt;14) (Starkstein et al., 1992; Beck et al., 1996). Individuals taking SSRIs (N=98, x2=5.14, p=0.023) or SNRIs (N=39; x2=5.43, p=0.020) were more likely to be clinically apathetic than those taking other depression medications (N=23; x2=1.28, p=0.26). Results of a multiple regression with age, education, disease duration, motor severity, DRS-2, BDI-II, and all psychotropic medications (anti-depressants, anti-anxiety, anti-psychotics) as independent variables explained 42.8% of the variance in total apathy scores (F[17,285]=12.550, p&lt;0.001). SSRIs were the only medication to significantly predict greater AS scores (ß=0.110, p=0.020) in this model. Less education (ß=-0.119, p=0.017) worse cognition (ß=-0.128, p=0.009), and greater depressive symptoms (ß=0.561, p&lt;0.001) were also significant predictors of apathy.Conclusions:These findings suggest that use of SSRIs, but not other antidepressants, is associated with greater apathy in PD. Given the interactive relationship between serotonin and dopamine, the current findings highlight the importance of considering apathy as a potential adverse effect when determining which anti-depressants to prescribe to individuals with PD. Similarly, switching a SSRI for an alternative anti-depressant in individuals with PD who are apathetic may be a potential treatment for apathy that needs further study. Longitudinal studies are also needed to elucidate the relationship of apathy and anti-depressant use over time, specifically to determine potential causality of this observed association. Funding: T32-NS082168

Is the cingulate island sign a marker for early dementia conversion in Parkinson's disease?

To investigate whether the cingulate island sign (CIS) ratio (i.e., the ratio of regional uptake in the posterior cingulate cortex relative to the precuneus and cuneus on cerebral perfusion scans) is associated with early dementia conversion in Parkinson's disease (PD). We enrolled 226 patients with newly diagnosed PD and 48 healthy controls who underwent dual-phase 18 F-FP-CIT PET scans. Patients with PD were classified into three groups according to the CIS ratio on early-phase 18 F-FP-CIT PET images: a PD group with CIS or high CIS ratios (PD-CIS; n = 96), a PD group with inverse CIS or low CIS ratios (PD-iCIS; n = 40), and a PD group consisting of the remaining patients with normal CIS ratios (PD-nCIS; n = 90). We compared the risk of dementia conversion within a 5-year time point between the groups. There were no significant differences in age, sex, education, or baseline cognitive function between the PD groups. The PD-CIS group had higher Unified Parkinson's Disease Rating Scale (UPDRS) motor scores and more severely decreased dopamine transporter availability in the putamen. The PD-iCIS group had a smaller hippocampal volume compared with the other groups. The risk of dementia conversion in the PD-CIS group did not differ from that in the PD-iCIS and PD-nCIS groups. Meanwhile, the PD-iCIS group had a higher risk of dementia conversion than the PD-nCIS group. The results of this study suggest that inverse CIS, rather than CIS, is relevant to early dementia conversion in patients with PD.

Deep Brain Stimulation of the Subthalamic Nucleus in a Patient With X-Linked Dystonia-Parkinsonism. (P11-11.001)

<h3>Objective:</h3> N/A <h3>Background:</h3> X-linked dystonia-parkinsonism (XDP) is one of the genetic causes of generalized dystonia. Both dystonia and parkinsonism components of the disease are frequently resistant to pharmacologic treatment. Deep brain stimulation (DBS) of the globus pallidus pars interna (GPi) is an effective treatment modality, especially for dystonic manifestations of XDP. The subthalamic nucleus (STN) is a known DBS target in Parkinson disease but it is less frequently used for treatment of dystonia. In our case report we describe a patient with XDP who underwent bilateral STN DBS with notable improvement in parkinsonism and dystonia. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> Our patient is a right-handed Filipino man from the island of Panay. He developed bilateral parkinsonism, blepharospasm, oromandibular and cervical dystonia at the age of 51. Diagnosis of XDP was confirmed with genetic testing. Marked improvement of Unified Parkinson Disease Rating Scale (UPDRS) motor score in response to levodopa administration was demonstrated (65 off and 36 on). His pre-DBS Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) was 27.5. Bilateral GPi were initially selected as a target for DBS lead placement based on previously published data. Surgical target was subsequently changed to bilateral STN due to distortion in GPi anatomy likely secondary to long-standing disease. Medtronic Percept PC neurostimulator with Sensight DBS leads were used. There was no surgical complications. Patient had an immediate improvement in tremor, bradykinesia and rigidity after his first programming visit; antidystonic effects of stimulation became evident over the next few weeks. There was substantial improvement in limb and oromandibular dystonia and mild effect on cervical dystonia and blepharospasm. His speech clarity became better as well. His motor UPDRS and BFMDRS decreased to 21 and 19, respectively. Gait, posture, ability to perform activities of daily living significantly improved. <h3>Conclusions:</h3> The subthalamic nucleus may be considered an alternative deep brain stimulation target in patients with X-linked dystonia-parkinsonism. <b>Disclosure:</b> Dr. Redko has nothing to disclose. Brian Kopell has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Medtronic. Brian Kopell has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Abbott Neuromodulation. Brian Kopell has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Enspire DBS. Dr. Tse has nothing to disclose.

CircEPS15, as a sponge of MIR24-3p ameliorates neuronal damage in Parkinson disease through boosting PINK1-PRKN-mediated mitophagy

ABSTRACT Despite growing evidence that has declared the importance of circRNAs in neurodegenerative diseases, the clinical significance of circRNAs in dopaminergic (DA) neuronal degeneration in the pathogenesis of Parkinson disease (PD) remains unclear. Here, we performed rRNA-depleted RNA sequencing and detected more than 10,000 circRNAs in the plasma samples of PD patients. In consideration of ROC and the correlation between Hohen-Yahr stage (H-Y stage) and Unified Parkinson Disease Rating Scale-motor score (UPDRS) of 40 PD patients, circEPS15 was selected for further research. Low expression of circEPS15 was found in PD patients and there was a negative positive correlation between the circEPS15 level and severity of PD motor symptoms, while overexpression of circEPS15 protected DA neurons against neurotoxin-induced PD-like neurodegeneration in vitro and in vivo. Mechanistically, circEPS15 acted as a MIR24-3p sponge to promote the stable expression of target gene PINK1, thus enhancing PINK1-PRKN-dependent mitophagy to eliminate damaged mitochondria and maintain mitochondrial homeostasis. Thus, circEPS15 rescued DA neuronal degeneration through the MIR24-3p-PINK1 axis-mediated improvement of mitochondrial function. This study reveals that circEPS15 exerts a critical role in participating in PD pathogenesis, and may give us an insight into the novel avenue to develop potential biomarkers and therapeutic targets for PD. Abbreviations: AAV: adeno-associated virus; DA: dopaminergic; FISH: fluorescence in situ hybridizations; HPLC: high-performance liquid chromatography; H-Y stage: Hohen-Yahr stage; LDH: lactate dehydrogenase; MMP: mitochondrial membrane potential; MPTP/p: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid; NC: negative control; PD: Parkinson disease; PINK1: PTEN induced kinase 1; PBS: phosphate-buffered saline; ROS: reactive oxygen species; SNpc: substantia nigra pars compacta; TEM: transmission electron microscopy; UPDRS: Unified Parkinson’s Disease Rating Scale-motor score

Disease-Associated α-Synuclein Aggregates as Biomarkers of Parkinson Disease Clinical Stage.

Robust biomarkers that can mirror Parkinson disease (PD) are of great significance. In this study, we present a novel approach to investigate disease-associated α-synuclein (αSyn) aggregates as biomarkers of PD clinical stage. We combined both seed amplification assay (SAA) and ELISA to provide a quantitative test readout that reflects the clinical severity of patients with PD. To attain this goal, we initially explored the potential of our test using 2 sets of human brain homogenates (pilot and validation sets) and then verified it with 2 independent human CSF cohorts; discovery (62 patients with PD and 34 controls) and validation (49 patients with PD and 48 controls) cohorts. We showed that oligomers-specific ELISA robustly quantified SAA end product from patients with PD or dementia with Lewy bodies with high sensitivity and specificity scores (100%). Analysis also demonstrated that seeding activity could be detected earlier with oligomeric ELISA as the test readout rather than SAA alone. Of more importance, multiplexing the assays provided robust information about the patients' clinical disease stage. In the discovery cohort, levels of CSF-seeded αSyn oligomers correlated with the severity of the clinical symptoms of PD as measured by the Unified Parkinson Disease Rating Scale (UPDRS) motor (r = 0.58, p < 0.001) and Hoehn and Yahr (H&Y) scores (r = 0.43, p < 0.01). Similar correlations were observed in the validation cohort between the concentrations of CSF-seeded αSyn oligomers and both UPDRS motor (r = 0.50, p < 0.01) and H&Y scores (r = 0.49, p < 0.01). At 20 hours, receiver operating characteristic curves analysis yielded a sensitivity of 91.9% (95% CI 82.4%-96.5%) and a specificity of 85.3% (95% CI 69.8%-93.5%), with an area under the curve of 0.969 for CSF-seeded αSyn oligomers differentiating those with PD from controls in the discovery CSF cohort, whereas, a sensitivity of 80.7% (95% CI 69.1%-88.5%), a specificity of 76.5% (95% CI 60.0%-87.5%), and area under the curve of 0.860 were generated with thioflavin T maximum intensity of fluorescence at the same time point. We showed that combining SAA and ELISA assays is a more promising diagnostic tool than SAA alone, providing information about the disease stage by correlating with clinical measures of disease severity. This study provides Class III evidence that CSF-seeded αSyn oligomers can accurately discriminate patients with PD and normal controls and CSF-seeded αSyn oligomers levels correlate with PD severity.

Validation of STOP, STOP-BANG, STOP-BAG, STOP-B28, and GOAL screening tools for identification of obstructive sleep apnea in patients with Parkinson disease.

Obstructive sleep apnea (OSA) is common in Parkinson disease (PD). Questionnaires can be used as screening tools and have been used as a surrogate definition of OSA in large-scale research. This study aimed to validate the performance of STOP, STOP-BANG, STOP-BAG, STOP-B28, and GOAL and OSA predictors as tools to identify OSA in PD. Data were analyzed from a PD cohort study in which OSA was diagnosed using laboratory polysomnography. We calculated sensitivity and specificity of each questionnaire for OSA using different definitions and performed receiver operating characteristics curve analysis. Linear regression was used to assess adjusted associations between questionnaires and outcomes: Montreal Cognitive Assessment, Epworth Sleepiness Scale, and Movement Disorder Society revision of the Unified Parkinson Disease Rating Scale. Questionnaire data were available for 68 PD patients (61.8% male, mean age 64.5 [standard deviation 9.9] years, and Hoehn and Yahr score 2.1 [0.8]). OSA (apnea-hypopnea index ≥ 15 events/h) occurred in 69.4% of participants. STOP-B28 ≥ 2 presented a higher sensitivity for OSA than STOP ≥ 2 (0.76 vs 0.65, respectively) and slightly lower specificity (0.65 vs 0.70, respectively). GOAL ≥ 2 had the highest sensitivity but poor specificity. Loud snoring had sensitivity 0.63 and specificity 0.65. STOP and snoring were significantly associated with Montreal Cognitive Assessment, Epworth Sleepiness Scale, and Movement Disorder Society revision of the Unified Parkinson Disease Rating Scale (total, motor, and nonmotor); STOP-BANG, STOP-BAG, and STOP-B28 showed associations with most outcomes, but the GOAL showed none. The STOP-B28 followed by STOP and presence of loud snoring alone seem to have the best overall properties to identify PD patients with OSA, whose clinical characteristics differ from the general population with OSA. Gomes T, Benedetti A, Lafontaine A-L, Kimoff RJ Robinson A, Kaminska M. Validation of STOP, STOP-BANG, STOP-BAG, STOP-B28, and GOAL screening tools for identification of obstructive sleep apnea in patients with Parkinson disease. J Clin Sleep Med. 2023;19(1):45-54.

Morphometric magnetic resonance imaging cortico-subcortical features in Parkinson's disease with mild cognitive impairment.

Parkinson's disease (PD) patients with cognitive impairment undergo progressive atrophy of several cortical and subcortical areas. The aim was to study the magnetic resonance imaging (MRI) morphometric features of PD patients with mild cognitive impairment (MCI). Patients from the Parkinson's Disease Cognitive Impairment Study (PACOS) cohort with an available structural volumetric brain MRI and morphometric measurements of the midbrain and pons areas, middle cerebellar peduncle, superior cerebellar peduncle width and midbrain anteroposterior diameter (A-Pdiam) were included. MCI was diagnosed according to the Movement Disorder Society level II criteria. Additionally, cortical thickness analysis was performed and correlated with morphometric brainstem measurements. Morphometric measurements were available for 168 subjects, of whom 67 (39.9%) were diagnosed with PD-MCI. The mean age (± standard deviation) of the sample was 64.2 ± 9.8. Amongst patients, 84 (50%) were men with a disease duration of 5.2 ± 5.4 years and a Unified Parkinson's Disease Rating Scale-Motor Examination score of 32.1 ± 12.9. In the univariate and multivariate analysis, after adjusting for age, sex, years of schooling and disease duration, MCI was associated with midbrain area (odds ratio 0.98; 95% confidence interval 0.96-0.99; p=0.048) and A-Pdiam (odds ratio 0.63; 95% confidence interval 0.46-0.86; p=0.005). Furthermore, 121 PD patients underwent cortical thickness analysis, which showed the presence of cortical thinning in lateral orbitofrontal regions of patients with PD-MCI. No correlation was found between cortical thickness and brainstem morphometric measurements. A mild midbrain atrophy and the presence of frontal cortical thickness reduction might be considered a structural MRI feature of PD patients with MCI.

Energy Decline May Predict Mild Parkinsonian Signs in Community-Dwelling Older Adults

Mild Parkinsonian Signs (MPS) are common in older adults without overt neurological disease. MPS are often progressive and predict disability and dementia, yet little is known about predictors for MPS. Low self-reported energy is associated with mobility impairment, which is a hallmark of MPS. Yet whether self-reported energy relates to MPS is unknown. We explored the association of changes in self-reported energy with MPS in 293 participants (aged 83 ± 2.8 years, 58% women, 61% White) free of dementia and Parkinson’s Disease in the Health, Aging and Body Composition Study. Self-reported energy was assessed on a 0-10 scale annually between Year 2 and Year 10 (mean follow-up: 8 years) and its slope was estimated via linear mixed effects models. MPS were evaluated at Year 10 based on the Unified Parkinson Disease Rating Scale motor component. On average, self-reported energy declined 0.06 points per year. In a linear regression model adjusted for age, fatigue, and comorbidities, those with MPS had steeper SEL decline (β [Standard Error] = -0.358 [0.119]) in the prior eight years than those without MPS. Thus, declining self-reported energy may be a risk factor for MPS. Self-reported energy is easily evaluated in routine clinic visits, and may be a modifiable risk factor that can be targeted to reduce the incidence of MPS.

Effects of resistance training on postural control in Parkinson's disease: a randomized controlled trial.

Postural instability affects Parkinson's disease (PD) patients' postural control right from the early stages of the disease. The benefits of resistance training (RT) for balance and functional capacity have been described in the literature, but few studies have been conducted showing its effects on PD patients' postural control. To investigate the effects of a three-month RT intervention on static posturography (SP) measurements and clinical functional balance assessment among PD patients. Seventy-four patients were randomly assigned to a three-month RT intervention consisting of using weightlifting machines at a gym (gym group) or RT consisting of using free weights and elastic bands (freew group), or to a control group. The participants were evaluated at baseline, three months and six months. We evaluated changes of SP measurements under eyes-open, eyes-closed and dual-task conditions (primary endpoint), along with motor performance and balance effects by means of clinical scales, dynamic posturography and perceptions of quality of life (secondary endpoints). There were no significant interactions in SP measurements among the groups. Unified Parkinson Disease Rating Scale (UPDRS-III) motor scores decreased in both RT groups (p<0.05). Better perceived quality of life for the mobility domain was reported in the gym group while functional balance scores improved in the freew group, which were maintained at the six-month follow-up (p<0.05). This study was not able to detect changes in SP measurements following a three-month RT intervention. Both RT groups of PD patients showed improved motor performance, with positive balance effects in the freew group and better perceived quality of life in the gym group.

A Rapid Motor Task-Based Screening Tool for Parkinsonism in Community-Based Studies.

Background: The prevalence of parkinsonism in developing countries is largely unknown due to difficulty in ascertainment because access to neurologists is often limited.Objective: Develop and validate a parkinsonism screening tool using objective motor task-based tests that can be administered by non-clinicians.Methods: In a cross-sectional population-based sample from South Africa, we evaluated 315 adults, age >40, from an Mn-exposed (smelter) community, using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3), Purdue grooved pegboard, and kinematic-UPDRS3-based motor tasks. In 275 participants (training dataset), we constructed a linear regression model to predict UPDRS3. We selected motor task summary measures independently associated with UPDRS3 (p < 0.05). We validated the model internally in the remaining 40 participants from the manganese-exposed community (test dataset) using the area under the receiver operating characteristic curve (AUC), and externally in another population-based sample of 90 participants from another South African community with only background levels of environmental Mn exposure.Results: The mean UPDRS3 score in participants from the Mn-exposed community was 9.1 in both the training and test datasets (standard deviation = 6.4 and 6.1, respectively). Together, 57 (18.1%) participants in this community had a UPDRS3 ≥ 15, including three with Parkinson's disease. In the non-exposed community, the mean UPDRS3 was 3.9 (standard deviation = 4.3). Three (3.3%) had a UPDRS3 ≥ 15. Grooved pegboard time and mean velocity for hand rotation and finger tapping tasks were strongly associated with UPDRS3. Using these motor task summary measures and age, the UPDRS3 predictive model performed very well. In the test dataset, AUCs were 0.81 (95% CI 0.68, 0.94) and 0.91 (95% CI 0.81, 1.00) for cut points for neurologist-assessed UPDRS3 ≥ 10 and UPDRS3 ≥ 15, respectively. In the external validation dataset, the AUC was 0.85 (95% CI 0.73, 0.97) for UPDRS3 ≥ 10. AUCs were 0.76–0.82 when excluding age.Conclusion: A predictive model based on a series of objective motor tasks performs very well in assessing severity of parkinsonism in both Mn-exposed and non-exposed population-based cohorts.

Severity of parkinsonism associated with environmental manganese exposure

BackgroundExposure to occupational manganese (Mn) is associated with neurotoxic brain injury, manifesting primarily as parkinsonism. The association between environmental Mn exposure and parkinsonism is unclear. To characterize the association between environmental Mn exposure and parkinsonism, we performed population-based sampling of residents older than 40 in Meyerton, South Africa (N = 621) in residential settlements adjacent to a large Mn smelter and in a comparable non-exposed settlement in Ethembalethu, South Africa (N = 95) in 2016–2020.MethodsA movement disorders specialist examined all participants using the Unified Parkinson Disease Rating Scale motor subsection part 3 (UPDRS3). Participants also completed an accelerometry-based kinematic test and a grooved pegboard test. We compared performance on the UPDRS3, grooved pegboard, and the accelerometry-based kinematic test between the settlements using linear regression, adjusting for covariates. We also measured airborne PM2.5-Mn in the study settlements.ResultsMean PM2.5-Mn concentration at a long-term fixed site in Meyerton was 203 ng/m3 in 2016–2017 – approximately double that measured at two other neighborhoods in Meyerton. The mean Mn concentration in Ethembalethu was ~ 20 times lower than that of the long-term Meyerton site. UPDRS3 scores were 6.6 (CI 5.2, 7.9) points higher in Meyerton than Ethembalethu residents. Mean angular velocity for finger-tapping on the accelerometry-based kinematic test was slower in Meyerton than Ethembalethu residents [dominant hand 74.9 (CI 48.7, 101.2) and non-dominant hand 82.6 (CI 55.2, 110.1) degrees/second slower]. Similarly, Meyerton residents took longer to complete the grooved pegboard, especially for the non-dominant hand (6.9, CI -2.6, 16.3 s longer).ConclusionsEnvironmental airborne Mn exposures at levels substantially lower than current occupational exposure thresholds in the United States may be associated with clinical parkinsonism.

Bilateral Deep Brain Stimulation is the Procedure to Beat for Advanced Parkinson Disease: A Meta-Analytic, Cost-Effective Threshold Analysis for Focused Ultrasound

Parkinson disease (PD) impairs daily functioning for an increasing number of patients and has a growing national economic burden. Deep brain stimulation (DBS) may be the most broadly accepted procedural intervention for PD, but cost-effectiveness has not been established. Moreover, magnetic resonance image-guided focused ultrasound (FUS) is an emerging incisionless, ablative treatment that could potentially be safer and even more cost-effective. To (1) quantify the utility (functional disability metric) imparted by DBS and radiofrequency ablation (RF), (2) compare cost-effectiveness of DBS and RF, and (3) establish a preliminary success threshold at which FUS would be cost-effective compared to these procedures. We performed a meta-analysis of articles (1998-2018) of DBS and RF targeting the globus pallidus or subthalamic nucleus in PD patients and calculated utility using pooled Unified Parkinson Disease Rating Scale motor (UPDRS-3) scores and adverse events incidences. We calculated Medicare reimbursements for each treatment as a proxy for societal cost. Over a 22-mo mean follow-up period, bilateral DBS imparted the most utility (0.423 quality-adjusted life-years added) compared to (in order of best to worst) bilateral RF, unilateral DBS, and unilateral RF, and was the most cost-effective (expected cost: $32 095 ± $594) over a 22-mo mean follow-up. Based on this benchmark, FUS would need to impart UPDRS-3 reductions of ∼16% and ∼33% to be the most cost-effective treatment over 2- and 5-yr periods, respectively. Bilateral DBS imparts the most utility and cost-effectiveness for PD. If our established success threshold is met, FUS ablation could dominate bilateral DBS's cost-effectiveness from a societal cost perspective.

Revisiting the L-Dopa Response as a Predictor of Motor Outcomes After Deep Brain Stimulation in Parkinson's Disease.

Objective: To investigate the correlation between preoperative response to the L-dopa challenge test and efficacy of deep brain stimulation (DBS) on motor function in Parkinson’s disease (PD).Methods: We retrospectively reviewed the data of 38 patients with idiopathic PD who underwent DBS surgery with a median follow-up duration of 7 months. Twenty underwent bilateral globus pallidus interna (GPi) DBS, and 18 underwent bilateral subthalamic nucleus (STN) DBS. The Movement Disorder Society Unified Parkinson Disease Rating Scale-Motor Part (MDS UPDRS-III) was assessed before surgery and at the last follow-up in different medication and stimulation conditions, respectively.Results: Pearson’s correlation analysis revealed a positive correlation between preoperative L-dopa challenge responsiveness and GPi-DBS responsiveness on the total score (R2 = 0.283, p = 0.016) but not on the non-tremor total score (R2 = 0.158, p = 0.083) of MDS UPDRS-III. Such correlation remained significant (R2′ = 0.332, p = 0.010) after controlling for age at the time of surgery as confounding factor by partial correlation analysis. The preoperative L-dopa challenge responsiveness was significantly correlated with the tremor-controlling outcome of GPi-DBS (R2 = 0.390, p = 0.003). In contrast, we found a positive correlation between preoperative L-dopa challenge responsiveness and STN-DBS responsiveness on the non-tremor total score (R2 = 0.290, p = 0.021), but not on the total score (R2 = 0.130, p = 0.141) of MDS UPDRS-III. The partial correlation analysis further demonstrated that the predictive value of preoperative L-dopa challenge responsiveness on the non-tremor motor outcome of STN-DBS was eliminated (R2′ = 0.120, p = 0.174) after controlling for age at the time of surgery as confounding factor.Interpretation: The short-term predictive value of preoperative response to the L-dopa challenge test for the motor outcome of GPi-DBS in PD was systematically described. Our findings suggest: (1) a solid therapeutic effect of GPi-DBS in treating L-dopa-responsive tremors; (2) a negative effect of age at the time of surgery on motor outcomes of STN-DBS, (3) a possible preference of STN- to GPi-DBS in L-dopa-resistant tremor control, and (4) a possible preference of GPi- to STN-DBS in elderly PD patients who have a satisfactory dopamine response.

Use of Functional MRI to Assess Effects of Deep Brain Stimulation Frequency Changes on Brain Activation in Parkinson Disease.

Models have been developed for predicting ideal contact and amplitude for subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson disease (PD). Pulse-width is generally varied to modulate the size of the energy field produced. Effects of varying frequency in humans have not been systematically evaluated. To examine how altered frequencies affect blood oxygen level-dependent activation in PD. PD subjects with optimized DBS programming underwent functional magnetic resonance imaging (fMRI). Frequency was altered and fMRI scans/Unified Parkinson Disease Rating Scale motor subunit (UPDRS-III) scores were obtained. Analysis using DBS-OFF data was used to determine which regions were activated during DBS-ON. Peak activity utilizing T-values was obtained and compared. At clinically optimized settings (n=14 subjects), thalamic, globus pallidum externa (GPe), and posterior cerebellum activation were present. Activation levels significantly decreased in the thalamus, anterior cerebellum, and the GPe when frequency was decreased (P <.001). Primary somatosensory cortex activation levels significantly decreased when frequency was increased by 30Hz, but not 60Hz. Sex, age, disease/DBS duration, and bilaterality did not significantly affect the data. Retrospective analysis of fMRI activation patterns predicted optimal frequency in 11/14 subjects. We show the first data with fMRI of STN DBS-ON while synchronizing cycling with magnetic resonance scanning. At clinically optimized settings, an fMRI signature of thalamic, GPe, and posterior cerebellum activation was seen. Reducing frequency significantly decreased thalamic, GPe, and anterior cerebellum activation. Current standard-of-care programming can take up to 6 mo using UPDRS-III testing alone. We provide preliminary evidence that using fMRI signature of frequency may have clinical utility and feasibility.

Movement disorders in 2020: clinical trials, genetic discoveries, and COVID-19

Movement disorders in 2020: clinical trials, genetic discoveries, and COVID-19

Pretreatment brain volumes can affect the effectiveness of deep brain stimulation in Parkinson's disease patients

We aimed to assess whether brain volumes may affect the results of deep brain stimulation (DBS) in patients with Parkinson’s disease (PD). Eighty-one consecutive patients with PD (male:female 40:41), treated with DBS between June 2012 and December 2017, were enrolled. Total and regional brain volumes were measured using automated brain volumetry (NeuroQuant). The Unified Parkinson Disease Rating Scale motor score quotient was used to assess changes in clinical outcome and compare the preoperative regional brain volume in patients categorized into the higher motor improvement and lower motor improvement groups based on changes in the postoperative scores. The study groups showed significant volume differences in multiple brain areas. In the higher motor improvement group, the anterior cingulate and right thalamus showed high volumes after false discovery rate (FDR) correction. In the lower motor improvement group, the left caudate, paracentral, right primary sensory and left primary motor cortex showed high volume, but no area showed high volumes after FDR correction. Our data suggest that the effectiveness of DBS in patients with PD may be affected by decreased brain volume in different areas, including the cingulate gyrus and thalamus. Preoperative volumetry could help predict outcomes in patients with PD undergoing DBS.

Association between freezing of gait and bone mineral density in patients with Parkinson's disease.

Parkinson's disease (PD) patients are at risk for developing bone health problems, and freezing of gait (FOG) in PD is associated with a high risk of falling and fracture. This study aimed to determine the association between FOG and bone mineral density (BMD) in patients with PD. We included 148 PD patients. FOG was assessed using the FOG Questionnaire (FOG-Q), and BMD was measured by dual-energy X-ray absorptiometry. Of 148 PD patients, 102 (68.9%) had FOG. PD patients with FOG were older and had longer disease duration, higher levodopa equivalent dose, higher modified Hoehn and Yahr stage, higher Unified PD Rating Scale motor score, higher FOG-Q score, higher total Non-Motor Symptom Scale score, and lower BMD scores in the femoral neck area than those without FOG. Pearson correlation analysis revealed that age, sex, body mass index, and age at onset were significantly correlated with areal BMDs in all areas. FOG-Q scores correlated negatively with areal BMDs in the total hip area and femoral neck, but not with areal BMD in the lumbar spine. Multivariate regression analysis showed that FOG-Q score was significantly correlated with areal BMD in the femoral neck, but not with areal BMDs in the lumbar spine or total hip. FOG in PD patients correlates significantly with BMD in the femoral neck area. Therefore, PD patients with FOG should be screened for osteoporosis.