Trial of Deferiprone in Parkinson's Disease.

BACKGROUND: Iron content is increased in the substantia nigra of persons with Parkinson's disease and may contribute to the pathophysiology of the disorder. Early research suggests that the iron chelator deferiprone can reduce nigrostriatal iron content in persons with Parkinson's disease, but its effects on disease progression are unclear. METHODS: We conducted a multicenter, phase 2, randomized, double-blind trial involving participants with newly diagnosed Parkinson's disease who had never received levodopa. Participants were assigned (in a 1:1 ratio) to receive oral deferiprone at a dose of 15 mg per kilogram of body weight twice daily or matched placebo for 36 weeks. Dopaminergic therapy was withheld unless deemed necessary for symptom control. The primary outcome was the change in the total score on the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS; range, 0 to 260, with higher scores indicating more severe impairment) at 36 weeks. Secondary and exploratory clinical outcomes at up to 40 weeks included measures of motor and nonmotor disability. Brain iron content measured with the use of magnetic resonance imaging was also an exploratory outcome. RESULTS: A total of 372 participants were enrolled; 186 were assigned to receive deferiprone and 186 to receive placebo. Progression of symptoms led to the initiation of dopaminergic therapy in 22.0% of the participants in the deferiprone group and 2.7% of those in the placebo group. The mean MDS-UPDRS total score at baseline was 34.3 in the deferiprone group and 33.2 in the placebo group and increased (worsened) by 15.6 points and 6.3 points, respectively (difference, 9.3 points; 95% confidence interval, 6.3 to 12.2; P<0.001). Nigrostriatal iron content decreased more in the deferiprone group than in the placebo group. The main serious adverse events with deferiprone were agranulocytosis in 2 participants and neutropenia in 3 participants. CONCLUSIONS: In participants with early Parkinson's disease who had never received levodopa and in whom treatment with dopaminergic medications was not planned, deferiprone was associated with worse scores in measures of parkinsonism than those with placebo over a period of 36 weeks. (Funded by the European Union Horizon 2020 program; FAIRPARK-II ClinicalTrials.gov number, NCT02655315.).

Phosphorylated α-synuclein in skin Schwann cells: a new biomarker for multiple system atrophy.

Multiple system atrophy (MSA) is characterized by accumulation of phosphorylated α-synuclein (p-syn) as glial cytoplasmic inclusions in the brain and a specific biomarker for this disorder is urgently needed. We aimed at investigating if p-syn can also be detected in skin Remak non-myelinating Schwann cells (RSCs) as Schwann cell cytoplasmic inclusions (SCCi) and may represent a reliable clinical biomarker for MSA. This cross-sectional diagnostic study evaluated skin p-syn in 96 patients: 46 with probable MSA (29 with parkinsonism type MSA and 17 with cerebellar type MSA), 34 with Parkinson's disease (PD) and 16 with dementia with Lewy bodies (DLB). We also included 50 healthy control subjects. Patients were recruited from five different medical centres. P-syn aggregates in skin sections were stained by immunofluorescence, followed by analyses with confocal microscopy and immuno-electron microscopy. All analyses were performed in a blinded fashion. Overall, p-syn aggregates were found in 78% of MSA patients and 100% of patients with PD/DLB, whereas they could not be detected in controls. As for neuronal aggregates 78% of MSA patients were positive for p-syn in somatic neurons, whereas all PD/DLB patients were positive in autonomic neurons. When analysing the presence of p-syn in RSCs, 74% of MSA patients were positive, whereas no such SCCi could be observed in PD/DLB patients. Analyses by immuno-electron microscopy confirmed that SCCi were only found in cases with MSA and thus absent in those with PD/DLB. In conclusion, our findings demonstrate that (i) fibrillar p-syn in RSCs is a pathological hallmark of MSA and may be used as a specific and sensitive disease biomarker; (ii) in Lewy body synucleinopathies (PD/DLB) only neurons contain p-syn deposits; and (iii) the cell-specific deposition of p-syn in the skin thus mirrors that of the brain in many aspects and suggests that non-myelinated glial cells are also involved in the MSA pathogenesis.

Patients accept therapy using embryonic stem cells for Parkinson's disease: a discrete choice experiment.

BACKGROUND: New disease-modifying ways to treat Parkinson's disease (PD) may soon become a reality with intracerebral transplantation of cell products produced from human embryonic stem cells (hESCs). The aim of this study was to assess what factors influence preferences of patients with PD regarding stem-cell based therapies to treat PD in the future. METHODS: Patients with PD were invited to complete a web-based discrete choice experiment to assess the importance of the following attributes: (i) type of treatment, (ii) aim of treatment, (iii) available knowledge of the different types of treatments, (iv) effect on symptoms, and (v) risk for severe side effects. Latent class conditional logistic regression models were used to determine preference estimates and heterogeneity in respondents' preferences. RESULTS: A substantial difference in respondents' preferences was observed in three latent preference patterns (classes). "Effect on symptoms" was the most important attribute in class 1, closely followed by "type of treatment," with medications as preferred to other treatment alternatives. Effect on symptoms was also the most important attribute in class 2, with treatment with hESCs preferred over other treatment alternatives. Likewise for class 3, that mainly focused on "type of treatment" in the decision-making. Respondents' class membership was influenced by their experience in treatment, side effects, and advanced treatment therapy as well as religious beliefs. CONCLUSIONS: Most of the respondents would accept a treatment with products emanating from hESCs, regardless of views on the moral status of embryos. Preferences of patients with PD may provide guidance in clinical decision-making regarding treatments deriving from stem cells.

Pain in patients with motor neuron disease: Variation of pain and association with disease severity, health-related quality of life and depression - A longitudinal study.

OBJECTIVES: To describe levels of pain over time during disease progression in individual patients and for a total sample of patients with motor neuron disease (MND), respectively, and to examine associations between pain, disease severity, health-related quality of life (HRQOL), and depression. METHODS: A prospective cohort study was conducted on 68 patients with MND, including data collected on five occasions over a period of 2 years. Pain was assessed using the Brief Pain Inventory - Short Form. Depression was assessed using the Amyotrophic Lateral Sclerosis (ALS)-Depression-Inventory (ADI-12). Disability progression was measured using the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised Version (ALSFRS-R). HRQOL was assessed using the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5). RESULTS: Participants reported great individual variation over time. The median level of pain was 4 (min 0 and max 10). Higher levels of pain during the last 24 h were associated with higher depression scores (ADI-12), poorer quality of life (ALSAQ-5), and lower reporting of fine and gross motor skills (ALSFRS-R). Baseline pain levels did not predict future values of depression and function. Individuals reporting average pain >3 experienced more hopelessness toward the future and reported higher depression scores compared with participants reporting average pain <3. SIGNIFICANCE OF RESULTS: Great within-individual variation of pain intensity was reported. Pain intensity was associated with depression, function and HRQOL cross-sectionally, but it did not have a strong prognostic value for future depression, function, or HRQOL. Patients with MND should be offered frequent assessment of pain and depressive symptoms in person-centered care, allowing for individualization of treatment.

Patients' views on using human embryonic stem cells to treat Parkinson's disease: an interview study.

BACKGROUND: Human embryonic stem cells (hESC) as a source for the development of advanced therapy medicinal products are considered for treatment of Parkinson's disease (PD). Research has shown promising results and opened an avenue of great importance for patients who currently lack a disease modifying therapy. The use of hESC has given rise to moral concerns and been the focus of often heated debates on the moral status of human embryos. Approval for marketing is still pending. OBJECTIVE: To Investigate the perspectives and concerns of patients with PD, patients being the directly concerned stakeholders in the ethical discussion. METHODS: Qualitative semi-structured interviews related to this new therapy in seventeen patients from two Swedish cities. RESULTS: The participants expressed various interests related to the use of human embryos for development of medicinal therapies; however, overall, they were positive towards the use of hESC for treatment of PD. It was deemed important that the donating woman or couple made the choice to donate embryos voluntarily. Furthermore, there were concerns that the industry does not always prioritise the patient over profit; thus, transparency was seen as important.

Attitudes and values among the Swedish general public to using human embryonic stem cells for medical treatment.

BACKGROUND: The use of human embryonic stem cells (ES cells) for the development of medical therapies is surrounded with moral concerns. The aim of this study was to assess the public's attitudes toward the use of ES cells for treatment of Parkinson's disease (PD) and other diseases, what factors are most important to consider when using ES cells for drug development, and if there is an association between religious beliefs and attitudes toward using ES cells for medical treatment. METHODS: A randomly selected sample of the Swedish public, aged 18-87-years-old, completed an online survey (n = 467). The survey assessed socio-demographics, religious views, perceived moral status of the embryo, and attitudes toward using ES cells for medical treatment of PD and other diseases. Adjusted odds ratios (ORs) and 95% confidence intervals (CI) for positive vs. negative attitude toward using ES cells for drug development were computed using logistic regression. RESULTS: The respondents were positive about using ES for treatment; specifically, 70% totally agreed that it is acceptable to use ES cells for treatment of PD, while 40% totally agreed that it is acceptable to use ES cells for treatment but induced pluripotent cells is just as efficient. Religion being of little importance in one's life was associated with a positive attitude toward using ES cells for treatment of PD (adjusted OR 6.39, 95% CI 2.78-14.71). The importance of being able "to access new, effective treatments against diseases that do not have any treatment available" was ranked as the most important factor to consider when using ES cells for drug development. CONCLUSION: Most respondents are positive about using ES cells for drug development, and making effective treatments accessible to those who do not have any. However, these attitudes are influenced by the specific disorder that the drug development is intended for, as well as the religious views and perceived moral status of the early embryo.

Proenkephalin Decreases in Cerebrospinal Fluid with Symptom Progression of Huntington's Disease.

OBJECTIVE: Identifying molecular changes that contribute to the onset and progression of Huntington's disease (HD) is of importance for the development and evaluation of potential therapies. METHODS: We conducted an unbiased mass-spectrometry proteomic analysis on the cerebrospinal fluid of 12 manifest HD patients (ManHD), 13 pre-manifest (preHD), and 38 controls. A biologically plausible and significant possible biomarker was validated in samples from a separate cohort of patients and controls consisting of 23 ManHD patients and 23 controls. RESULTS: In ManHD compared to preHD, 10 proteins were downregulated and 43 upregulated. Decreased levels of proenkephalin (PENK) and transthyretin were closely linked to HD symptom severity, whereas levels of 15 upregulated proteins were associated with symptom severity. The decreased PENK levels were replicated in the separate cohort where absolute quantitation was performed. CONCLUSIONS: We hypothesize that declining PENK levels reflect the degeneration of medium spiny neurons (MSNs) that produce PENK and that assays for PENK may serve as a surrogate marker for the state of MSNs in HD. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Pain, disease severity and associations with individual quality of life in patients with motor neuron diseases.

BACKGROUND: Up to 85% of people with motor neuron disease (MND) report pain, but whether pain has negative impact on quality of life is unclear. The aim was to study associations between pain, disease severity and individual quality of life (IQOL) in patients with MND. METHODS: In this cross sectional study, 61 patients were recruited from four multidisciplinary teams in Sweden, whereof 55 responded to the pain measure (The Brief Pain Inventory - Short form) and were included in the main analyses. Disease severity was measured with the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised Version, and individual quality of life was measured with a study-specific version of the Schedule for the Evaluation of Individual Quality of Life - Direct Weighting. RESULTS: Forty-one (74%) of the participants who answered BPI-SF (n = 55) reported pain. Thirty-nine (71%) of those reported pain during the past 24 h. The severity of pain was on average moderate, with eight participants (14%) reporting severe pain (PSI ≥ 7). Satisfaction with IQOL for the entire sample was good (scale 1-7, where 1 equals poor quality of life): median 5, interquartile range (IQR) 2.75 and there was no difference in satisfaction with IQOL between those reporting pain/not reporting pain (median 5, IQR 2/median 5, IQR 3.5, Mann-Whitney U = 249, p = 0.452). There was neither any correlation between pain severity and satisfaction with IQOL, nor between disease severity and satisfaction with IQOL. CONCLUSIONS: The results add to the hypothesis that associations between non-motor symptoms such as pain prevalence and pain severity and IQOL in MND are weak. Pain prevalence was high and the results pointed to that some participants experienced high pain severity, which indicate that pain assessments and pain treatments tailored to the specific needs of the MND population should be developed and scientifically evaluated.

A Phase 2a Trial Investigating the Safety and Tolerability of the Novel Cortical Enhancer IRL752 in Parkinson's Disease Dementia.

BACKGROUND: IRL752 is a novel small-molecule compound that acts to regioselectively enhance norepinephrine, dopamine, and acetylcholine neurotransmission in the cerebral cortex. OBJECTIVE: The primary objective of the trial was to investigate the safety and tolerability of IRL752 in patients with Parkinson's disease and dementia. METHODS: Patients with Parkinson's disease and dementia were randomized to IRL752 or placebo treatment (3:1 ratio) for 28 days. The study drug was given as an adjunct treatment to the patients' regular stable antiparkinsonian medication. Dosing was individually titrated for 14 days after which the dose was kept stable for an additional 14 days. RESULTS: A total of 32 patients were randomized to treatment, and 29 patients completed the 4-week treatment. Adverse events were generally mild and transient and were mostly reported during the dose titration phase. There were 2 serious adverse events, and none of them were related to the experimental treatment. The average dose achieved in the stable dose phase was 600 mg daily, yielding a 2-hour postdose plasma concentration of about 4 µM on day 28. Exploratory assessment of secondary outcomes indicated efficacy for symptoms and signs known to be poorly responsive to levodopa. CONCLUSIONS: IRL752 appears to be safe and well tolerated for a 4-week treatment in patients with Parkinson's disease and dementia. © 2020 International Parkinson and Movement Disorder Society.

Everyday Occupations and Other Factors in Relation to Mental Well-Being among Persons with Advanced Parkinson's Disease.

This cross-sectional study investigated performed activities and the level of satisfaction with everyday occupations among people (n = 67) with advanced Parkinson's disease (PD), and how these factors and experiences of social relationships were related to mental well-being. Managing one's hygiene and physical exercises were activities that the majority still performed, whereas few were engaged in work or other productive occupations. Perceived health problems and satisfaction with everyday occupations were important factors for mental well-being since satisfaction with everyday occupations may be an important focus for occupational therapists and other health professionals when supporting mental well-being among persons with advanced PD.

The effect of continuous levodopa treatment during the afternoon hours.

OBJECTIVE: The aim of this retrospective study was to investigate whether patients with Parkinson's disease, who are treated with levodopa-carbidopa intestinal gel (LCIG), clinically worsen during the afternoon hours and if so, to evaluate whether this occurs in all LCIG-treated patients or in a subgroup of patients. METHODS: Three published studies were identified and included in the analysis. All studies provided individual response data assessed on the treatment response scale (TRS), and patients were treated with continuous LCIG. Ninety-eight patients from the three studies fulfilled the criteria. t tests were performed to find differences on the TRS values between the morning and the afternoon hours, linear mixed effect models were fitted on the afternoon hours' evaluations to find trends of wearing-off, and patients were classified into three TRS categories (meaningful increase in TRS, meaningful decrease in TRS, non-meaningful increase or decrease). RESULTS: In all three studies, significant statistical differences were found between the morning TRS values and the afternoon TRS values (P-value <=0.001 in all studies). The linear mixed effect models had significant negative coefficients for time in two studies, and 48 out of 98 patients (49%) showed a meaningful decrease in TRS during the afternoon hours. CONCLUSION: The results from all studies were consistent, both in the proportion of patients in the three groups and in the value of TRS decrease in the afternoon hours. Based on these findings, there seems to be a group of patients with predictable "off" behavior in the later parts of the day.

A randomized, double-blind, placebo-controlled trial of camicinal in Parkinson's disease.

BACKGROUND: Delayed gastric emptying may impair l-dopa absorption, contributing to motor fluctuations. We evaluated the effect of camicinal (GSK962040), a gastroprokinetic, on the absorption of l-dopa and symptoms of PD. METHODS: Phase II, double-blind, placebo-controlled trial. Participants were randomized to receive camicinal 50 mg once-daily (n = 38) or placebo (n = 20) for 7 to 9 days. RESULTS: l-dopa exposure was similar with coadministration of camicinal compared to placebo. Median time to maximum l-dopa concentration was reduced, indicating more rapid absorption of l-dopa. Camicinal resulted in significant reduction in OFF time (-2.31 hours; 95% confidence interval: -3.71, -0.90), significant increase in ON time (+1.88 hours; 95% confidence interval: 0.28, 3.48) per day, and significant decrease in mean total MDS-UPDRS score (-12.5; 95% confidence interval: -19.67, -5.29). Camicinal treatment was generally well tolerated. CONCLUSIONS: PD symptom improvement with camicinal occurred in parallel with more rapid absorption of l-dopa. This study provides evidence of an improvement of the motor response to l-dopa in people with PD treated with camicinal 50 mg once-daily compared with placebo, which will require further evaluation. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Population pharmacokinetics of levodopa/carbidopa microtablets in healthy subjects and Parkinson's disease patients.

OBJECTIVES: Low dose, dispersible, levodopa/carbidopa microtablets with an automatic dose dispenser have been developed to facilitate individualized levodopa treatment. The aim of this study was to characterize the pharmacokinetics (PK) of levodopa and carbidopa after microtablet administration, and evaluate the impact of potential covariates. METHODS: The population PK analysis involved data from 18 healthy subjects and 18 Parkinson's disease patients included in two single-dose, open-label levodopa/carbidopa microtablet studies. The analysis was carried out using non-linear mixed effects modeling. Bodyweight was included on all disposition parameters according to allometric scaling. Potential influence of additional covariates was investigated using graphical evaluation and adjusted adaptive least absolute shrinkage and selection operator. RESULTS: Dispositions of levodopa and carbidopa were best described by a two- and one-compartment model respectively. Double-peak profiles were described using two parallel absorption compartments. Levodopa apparent clearance was found to decrease with increasing carbidopa dose (15% lower with 75 compared to 50 mg of carbidopa) and disease stage (by 18% for Hoehn and Yahr 1 to 4). Carbidopa apparent clearance was found to decrease with age (28% between the age of 60 and 80 years). An external evaluation showed the model to be able to reasonably well predict levodopa concentrations following multiple-dose microtablet administration in healthy subjects. CONCLUSIONS: The presented models adequately described the PK of levodopa and carbidopa, following microtablet administration. The developed model may in the future be combined with a pharmacokinetic-pharmacodynamic target and used for individualized dose selection, utilizing the flexibility offered by the microtablets.

Levodopa-entacapone-carbidopa intestinal gel in Parkinson's disease: A randomized crossover study.

BACKGROUND: The addition of oral entacapone to levodopa-carbidopa intestinal gel treatment leads to less conversion of levodopa to 3-O-methyldopa, thereby increasing levodopa plasma concentration. The objective of this study was to compare systemic levodopa exposure of the newly developed levodopa-entacapone-carbidopa intestinal gel after a 20% dose reduction with levodopa exposure after the usual levodopa-carbidopa intestinal gel dose in a randomized crossover trial in advanced Parkinson's disease patients. METHODS: In this 48-hour study, 11 patients treated with levodopa-carbidopa intestinal gel were randomized to a treatment sequence. Blood samples were drawn at prespecified times, and patient motor function was assessed according to the treatment response scale. RESULTS: Systemic exposure of levodopa did not differ significantly between treatments (ratio, 1.10 [95% confidence interval, 0.951-1.17]). Treatment response scale scores did not significantly differ between treatments (P = 0.84). CONCLUSIONS: Levodopa-entacapone-carbidopa intestinal gel allowed a lower amount of levodopa administration and was well tolerated. Long-term studies are needed to confirm the results. © 2016 International Parkinson and Movement Disorder Society.

Levodopa/carbidopa microtablets in Parkinson's disease: a study of pharmacokinetics and blinded motor assessment.

BACKGROUND: Motor function assessments with rating scales in relation to the pharmacokinetics of levodopa may increase the understanding of how to individualize and fine-tune treatments. OBJECTIVES: This study aimed to investigate the pharmacokinetic profiles of levodopa-carbidopa and the motor function following a single-dose microtablet administration in Parkinson's disease. METHODS: This was a single-center, open-label, single-dose study in 19 patients experiencing motor fluctuations. Patients received 150% of their individual levodopa equivalent morning dose in levodopa-carbidopa microtablets. Blood samples were collected at pre-specified time points. Patients were video recorded and motor function was assessed with six UPDRS part III motor items, dyskinesia score, and the treatment response scale (TRS), rated by three blinded movement disorder specialists. RESULTS: AUC0-4/dose and C max/dose for levodopa was found to be higher in Parkinson's disease patients compared with healthy subjects from a previous study, (p = 0.0008 and p = 0.026, respectively). The mean time to maximum improvement in sum of six UPDRS items score was 78 min (±59) (n = 16), and the mean time to TRS score maximum effect was 54 min (±51) (n = 15). Mean time to onset of dyskinesia was 41 min (±38) (n = 13). CONCLUSIONS: In the PD population, following levodopa/carbidopa microtablet administration in fasting state, the Cmax and AUC0-4/dose were found to be higher compared with results from a previous study in young, healthy subjects. A large between subject variability in response and duration of effect was observed, highlighting the importance of a continuous and individual assessment of motor function in order to optimize treatment effect.

Verification of a Method for Measuring Parkinson's Disease Related Temporal Irregularity in Spiral Drawings.

Parkinson's disease (PD) is a progressive movement disorder caused by the death of dopamine-producing cells in the midbrain. There is a need for frequent symptom assessment, since the treatment needs to be individualized as the disease progresses. The aim of this paper was to verify and further investigate the clinimetric properties of an entropy-based method for measuring PD-related upper limb temporal irregularities during spiral drawing tasks. More specifically, properties of a temporal irregularity score (TIS) for patients at different stages of PD, and medication time points were investigated. Nineteen PD patients and 22 healthy controls performed repeated spiral drawing tasks on a smartphone. Patients performed the tests before a single levodopa dose and at specific time intervals after the dose was given. Three movement disorder specialists rated videos of the patients based on the unified PD rating scale (UPDRS) and the Dyskinesia scale. Differences in mean TIS between the groups of patients and healthy subjects were assessed. Test-retest reliability of the TIS was measured. The ability of TIS to detect changes from baseline (before medication) to later time points was investigated. Correlations between TIS and clinical rating scores were assessed. The mean TIS was significantly different between healthy subjects and patients in advanced groups (p-value = 0.02). Test-retest reliability of TIS was good with Intra-class Correlation Coefficient of 0.81. When assessing changes in relation to treatment, TIS contained some information to capture changes from Off to On and wearing off effects. However, the correlations between TIS and clinical scores (UPDRS and Dyskinesia) were weak. TIS was able to differentiate spiral drawings drawn by patients in an advanced stage from those drawn by healthy subjects, and TIS had good test-retest reliability. TIS was somewhat responsive to single-dose levodopa treatment. Since TIS is an upper limb high-frequency-based measure, it cannot be detected during clinical assessment.

Stochastic anomaly detection in eye-tracking data for quantification of motor symptoms in Parkinson's disease.

Two methods for distinguishing between healthy controls and patients diagnosed with Parkinson's disease by means of recorded smooth pursuit eye movements are presented and evaluated. Both methods are based on the principles of stochastic anomaly detection and make use of orthogonal series approximation for probability distribution estimation. The first method relies on the identification of a Wiener model of the smooth pursuit system and attempts to find statistically significant differences between the estimated parameters in healthy controls and patients with Parkinson's disease. The second method applies the same statistical method to distinguish between the gaze trajectories of healthy and Parkinson subjects tracking visual stimuli. Both methods show promising results, where healthy controls and patients with Parkinson's disease are effectively separated in terms of the considered metric. The results are preliminary because of the small number of participating test subjects, but they are indicative of the potential of the presented methods as diagnosing or staging tools for Parkinson's disease.

Automatic Spiral Analysis for Objective Assessment of Motor Symptoms in Parkinson's Disease.

A challenge for the clinical management of advanced Parkinson's disease (PD) patients is the emergence of fluctuations in motor performance, which represents a significant source of disability during activities of daily living of the patients. There is a lack of objective measurement of treatment effects for in-clinic and at-home use that can provide an overview of the treatment response. The objective of this paper was to develop a method for objective quantification of advanced PD motor symptoms related to off episodes and peak dose dyskinesia, using spiral data gathered by a touch screen telemetry device. More specifically, the aim was to objectively characterize motor symptoms (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Digitized upper limb movement data of 65 advanced PD patients and 10 healthy (HE) subjects were recorded as they performed spiral drawing tasks on a touch screen device in their home environment settings. Several spatiotemporal features were extracted from the time series and used as inputs to machine learning methods. The methods were validated against ratings on animated spirals scored by four movement disorder specialists who visually assessed a set of kinematic features and the motor symptom. The ability of the method to discriminate between PD patients and HE subjects and the test-retest reliability of the computed scores were also evaluated. Computed scores correlated well with mean visual ratings of individual kinematic features. The best performing classifier (Multilayer Perceptron) classified the motor symptom (bradykinesia or dyskinesia) with an accuracy of 84% and area under the receiver operating characteristics curve of 0.86 in relation to visual classifications of the raters. In addition, the method provided high discriminating power when distinguishing between PD patients and HE subjects as well as had good test-retest reliability. This study demonstrated the potential of using digital spiral analysis for objective quantification of PD-specific and/or treatment-induced motor symptoms.

Comparison of quantitative [11C]PE2I brain PET studies between an integrated PET/MR and a stand-alone PET system.

PET/MR systems demanded great efforts for accurate attenuation correction (AC) but differences in technology, geometry and hardware attenuation may also affect quantitative results. Dedicated PET systems using transmission-based AC are regarded as the gold standard for quantitative brain PET. The study aim was to investigate the agreement between quantitative PET outcomes from a PET/MR scanner against a stand-alone PET system. Nine patients with Parkinsonism underwent two 80-min dynamic PET scans with the dopamine transporter ligand [11C]PE2I. Images were reconstructed with resolution-matched settings using 68Ge-transmission (stand-alone PET), and zero-echo-time MR (PET/MR) scans for AC. Non-displaceable binding potential (BPND) and relative delivery (R1) were evaluated using volumes of interest and voxel-wise analysis. Correlations between systems were high (r ≥ 0.85) for both quantitative outcome parameters in all brain regions. Striatal BPND was significantly lower on PET/MR than on stand-alone PET (-7%). R1 was significantly overestimated in posterior cortical regions (9%) and underestimated in striatal (-9%) and limbic areas (-6%). The voxel-wise evaluation revealed that the MR-safe headphones caused a negative bias in both parametric BPND and R1 images. Additionally, a significant positive bias of R1 was found in the auditory cortex, most likely due to the acoustic background noise during MR imaging. The relative bias of the quantitative [11C]PE2I PET data acquired from a SIGNA PET/MR system was in the same order as the expected test-retest reproducibility of [11C]PE2I BPND and R1, compared to a stand-alone ECAT PET scanner. MR headphones and background noise are potential sources of error in functional PET/MR studies.

Quantitative brain stem assessment in discriminating neurodegenerative disorders from normal pressure hydrocephalus.

BACKGROUND AND PURPOSE: Differentiating idiopathic normal pressure hydrocephalus (iNPH) from neurodegenerative disorders such as progressive supranuclear palsy (PSP), Multiple System Atrophy-parkinsonian type (MSA-P), and vascular dementia (VaD) is challenging due to overlapping clinical and neuroimaging findings. This study assesses if quantitative brain stem and cerebellum metrics can aid in this differentiation. METHODS: We retrospectively compared the sagittal midbrain area, midbrain to pons ratio, MR parkinsonism index (MRPI), and cerebellar atrophy in 30 PSP patients, 31 iNPH patients, 27 MSA-P patients, 32 VaD patients, and 25 healthy controls. Statistical analyses determined group differences, sensitivity, specificity, and the area under the receiver operating characteristic curves. RESULTS: There was an overlap in midbrain morphology between PSP and iNPH, as assessed with MRPI, midbrain to pons ratio, and midbrain area. A cutoff value of MRPI > 13 exhibited 84% specificity in distinguishing PSP from iNPH and 100% in discriminating PSP from all other conditions. A cutoff value of midbrain to pons ratio at <0.15 yielded 95% specificity for differentiating PSP from iNPH and 100% from all other conditions. A cutoff value of midbrain area at <87 mm2 exhibited 97% specificity for differentiating PSP from iNPH and 100% from all other conditions. All measures showed low sensitivity. Cerebellar atrophy did not differ significantly among groups. CONCLUSION: Our study questions MRPI's diagnostic performance in distinguishing PSP from iNPH. Simpler indices such as midbrain to pons ratio and midbrain area showed similar or better accuracy. However, all these indices displayed low sensitivity despite significant differences among PSP, MSA-P, and VaD.