GBA and APOE Impact Cognitive Decline in Parkinson's Disease: A 10-Year Population-Based Study.

BACKGROUND: Common genetic variance in apolipoprotein E (APOE), ß-glucocerebrosidase (GBA), microtubule-associated protein tau (MAPT), and α-synuclein (SNCA) has been linked to cognitive decline in Parkinson's disease (PD), although studies have yielded mixed results. OBJECTIVES: To evaluate the effect of genetic variants in APOE, GBA, MAPT, and SNCA on cognitive decline and risk of dementia in a pooled analysis of six longitudinal, non-selective, population-based cohorts of newly diagnosed PD patients. METHODS: 1002 PD patients, followed for up to 10 years (median 7.2 years), were genotyped for at least one of APOE-ε4, GBA mutations, MAPT H1/H2, or SNCA rs356219. We evaluated the effect of genotype on the rate of cognitive decline (Mini-Mental State Examanation, MMSE) using linear mixed models and the development of dementia (diagnosed using standardized criteria) using Cox regression; multiple comparisons were accounted for using Benjamini-Hochberg corrections. RESULTS: Carriers of APOE-ε4 (n = 281, 29.7%) and GBA mutations (n = 100, 10.3%) had faster cognitive decline and were at higher risk of progression to dementia (APOE-ε4, HR 3.57, P < 0.001; GBA mutations, HR 1.76, P = 0.001) than non-carriers. The risk of cognitive decline and dementia (HR 5.19, P < 0.001) was further increased in carriers of both risk genotypes (n = 23). No significant effects were observed for MAPT or SNCA rs356219. CONCLUSIONS: GBA and APOE genotyping could improve the prediction of cognitive decline in PD, which is important to inform the clinical trial selection and potentially to enable personalized treatment © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Prevalence of Progressive Supranuclear Palsy and Corticobasal Syndrome in Scotland.

INTRODUCTION: We estimated the point prevalence of progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) at regional and national levels in Scotland, UK, as there are few high-quality prevalence studies of these conditions. METHODS: Nationally, multiple methods of case ascertainment were used including clinician and nurse specialist referral, searches of ICD-10 diagnostic coding in routinely collected electronic health data (Scottish Morbidity Record), and patient self-referral. In one region, we also searched GP databases and unselected hospital correspondence. Cases were verified by clinical examination or medical record review. National and regional total and age-sex-stratified crude prevalence rates on December 31, 2018, were calculated. RESULTS: The regional crude point prevalence was 4.28 per 100,000 (95% CI 2.90, 6.31) for PSP and 2.05 per 100,000 (95% CI 1.17, 3.59) for CBS. The national crude prevalence rates were lower due to the greater reliance on passive case ascertainment. There were no clear sex differences. At a national level, the peak crude prevalence rate for both PSP and CBS was in the 70-79 age group. DISCUSSION: The prevalence rates of PSP and CBS were similar to previous estimates with little change over the past 20 years.

Development and validation of prognostic survival models in newly diagnosed Parkinson's disease.

OBJECTIVE: The objective of this study was to develop valid prognostic models to predict mortality, dependency, and "death or dependency" for use in newly diagnosed Parkinson's disease (PD). METHODS: The models were developed in the Parkinsonism Incidence in North-East Scotland study (UK, 198 patients) and validated in the ParkWest study (Norway, 192 patients), cohorts that attempted to identify and follow-up all new PD cases in the study area. Dependency was defined using the Schwab & England scale. We selected variables measured at time of diagnosis to include in the models. Internal validation and external validation were performed by calculating C-statistics (discrimination) and plotting observed versus predicted risk in quantiles of predicted risk (calibration). RESULTS: Older age, male sex, increased severity of axial features, and Charlson comorbidity index were independent prognostic factors in the mortality model. Increasing age, higher smoking history, increased severity of axial features, and lower MMSE score were independent predictors in the models of dependency and "death or dependency." Each model had very good internal calibration and very good or good discrimination (internal and external C-statistics for the models were 0.73-0.75 and 0.68-0.78, respectively). Although each model clearly separated patients into groups according to risk, they tended to overestimate risk in ParkWest. The models were recalibrated to the baseline risk in the ParkWest study and then calibrated well in this cohort. CONCLUSIONS: We have developed prognostic models for predicting medium-term risk of important clinical outcomes in newly diagnosed PD. These models have validity for use for stratification of randomization, confounder adjustment, and case-mix correction, but they are inadequate for individualized prognostication. © 2017. The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Association of glucocerebrosidase polymorphisms and mutations with dementia in incident Parkinson's disease.

INTRODUCTION: Both polymorphisms and mutations in glucocerebrosidase (GBA) may influence the development of dementia in patients with Parkinson's disease. METHODS: Four hundred forty-two patients and 419 controls were followed for 7 years. Dementia was diagnosed using established criteria. Participants were analyzed for GBA genetic variants, including E326K, T369M, and L444P. Associations between GBA carrier status and dementia were assessed with Cox survival analysis. RESULTS: A total of 12.0% of patients with Parkinson's disease carried a GBA variant, and nearly half (22/53) of them progressed to dementia during follow-up. Carriers of deleterious GBA mutations (adjusted hazard ratio 3.81, 95% confidence interval 1.35 to 10.72; P = .011) or polymorphisms (adjusted hazard ratio 1.79; 95% confidence interval 1.07 to 3.00; P = .028) progressed to dementia more rapidly than noncarriers. DISCUSSION: GBA variants are of great clinical relevance for the development of dementia in Parkinson's disease, especially due to the relatively higher frequency of these alleles compared with other risk alleles.

Predictors of functional dependency in Parkinson's disease.

BACKGROUND: Functional dependency, the need for help in basic activities of daily living, is an important patient-oriented outcome. We aimed to describe the development of dependency in Parkinson's disease (PD) and identify independent prognostic factors for this outcome. METHODS: We analyzed data from the Parkinsonism Incidence in North-East Scotland (PINE) study, a prospective, community-based incident cohort of PD with ongoing follow-up. We described the development of dependency defined by a Schwab & England score of < 80% and a Barthel Index of <19. We identified the baseline predictors of dependency using multivariable Cox regression. RESULTS: In 198 patients with PD, the rate of development of dependency was 14 per 100 person years. Older age at diagnosis (hazard ratio for 10-year increase 2.23 [95% confidence interval 1.66-2.98]), greater smoking history (hazard ratio for 10-pack-year increase, 1.15 [1.04-1.26]), more severe axial impairment (hazard ratio for 5-point increase in sum of axial items from UPDRS scale, 1.78 [1.30-2.44]), and lower MMSE score (hazard ratio 0.88 [0.79-0.98]) were independently associated with a higher risk of dependency as defined by Schwab & England. Only older age (hazard ratio for 10-year increase 1.35 [1.04-1.76]) and severity of axial impairment (hazard ratio for 5-point increase 1.85 [1.31-2.62]) were associated with a higher risk of dependency as defined by the Barthel Index. Sex, deprivation, comorbidity, overall UPDRS motor score, and disease stage were not independently associated with dependency. CONCLUSION: This is the first community-based study of dependency in PD. There was a high rate of dependency development. Older age, more smoking, more axial impairment, and poorer cognition were independent predictors. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

A review of clinical trial designs used to detect a disease-modifying effect of drug therapy in Alzheimer's disease and Parkinson's disease.

BACKGROUND: Disease-modification clinical trials in neurodegenerative disorders have struggled to separate symptomatic effects of putative agents from disease-modification. In response, a variety of clinical trial designs have been developed. A systematic review was undertaken to examine which trial designs have been used in Alzheimer's disease (AD) and Parkinson's disease (PD) to detect disease-modifying, as opposed to symptomatic, drug effects. In addition we aimed to identify novel clinical trial designs used in the past or planned for use in the future. We aimed to critique whether the methods used would have identified true disease-modification. METHODS: MEDLINE, Embase and CENTRAL (1980-2015) were searched to identify papers meriting review in full. ClinicalTrials.gov was searched to identify unpublished or planned randomised controlled trials (RCTs). We included RCTs in PD or AD which aimed to demonstrate the disease-modifying properties of drug therapy and differentiate that benefit from any symptomatic effect. RESULTS: 128 RCTs were finally included: 84 in AD (59 published, 25 unpublished); 44 in PD (36 published, 8 unpublished). A variety of clinical trial designs were applied including long-term follow-up, wash-in and wash-out analyses, randomised delayed-start, the use of time-to-event outcome measures and surrogate disease progression biomarkers. Deficiencies in each of these design strategies, the quantity of missing data in included RCTs and the methods used to deal with missing data, meant that none of the included studies convincingly demonstrated disease-modification. No truly novel clinical trial designs were identified. CONCLUSION: We currently believe that the best clinical trial design available to demonstrate disease-modification is a long-term follow-up study, in which an examination is made for sustained divergence in outcome measures between treatment arms over the study period.

Mortality in Parkinson's disease: a systematic review and meta-analysis.

This study was undertaken to perform a systematic review and meta-analysis of studies of mortality in Parkinson's disease (PD) and to investigate which factors were associated with mortality. We conducted comprehensive searches of studies reporting a ratio of mortality in PD versus controls, descriptive survival measures, or factors predicting survival; assessed study quality; and extracted relevant data. Descriptive analysis, meta-analysis, and meta-regression were performed as appropriate. Eighty-eight studies were included in the review with variable study methods and quality. Almost all studies reported increased mortality in PD (vs. controls), with mortality ratios ranging from 0.9 to 3.8, with major between-study heterogeneity. Inception cohorts were more consistent with a pooled mortality ratio of approximately 1.5. Inception cohorts, measurements at longer follow-up duration, and older study recruitment year were associated with lower mortality ratios, but these findings were not robust in sensitivity analyses. Within studies, mortality ratios increased over time. No robust evidence was found that mortality has decreased after the introduction of levodopa (L-dopa). On average, PD survival reduced by approximately 5% every year of follow-up, although there was significant heterogeneity. In post-mortem studies, mean duration until death ranged from 6.9 to 14.3 years. Increasing age and presence of dementia were most commonly associated with increased mortality. Parkinson's disease is associated with increased mortality, but major heterogeneity is seen in estimates of mortality, which is probably explained by variable methodology and patient selection. Individual-patient-data meta-analysis of high-quality inception studies with long-term follow-up would be the optimal way to investigate the factors influencing mortality.

Outcome after conservative management or intervention for unruptured brain arteriovenous malformations.

IMPORTANCE: Whether conservative management is superior to interventional treatment for unruptured brain arteriovenous malformations (bAVMs) is uncertain because of the shortage of long-term comparative data. OBJECTIVE: To compare the long-term outcomes of conservative management vs intervention for unruptured bAVM. DESIGN, SETTING, AND POPULATION: Population-based inception cohort study of 204 residents of Scotland aged 16 years or older who were first diagnosed as having an unruptured bAVM during 1999-2003 or 2006-2010 and followed up prospectively for 12 years. EXPOSURES: Conservative management (no intervention) vs intervention (any endovascular embolization, neurosurgical excision, or stereotactic radiosurgery alone or in combination). MAIN OUTCOMES AND MEASURES: Cox regression analyses, with multivariable adjustment for prognostic factors and baseline imbalances if hazards were proportional, to compare rates of the primary outcome (death or sustained morbidity of any cause by Oxford Handicap Scale [OHS] score ≥2 for ≥2 successive years [0 = no symptoms and 6 = death]) and the secondary outcome (nonfatal symptomatic stroke or death due to bAVM, associated arterial aneurysm, or intervention). RESULTS: Of 204 patients, 103 underwent intervention. Those who underwent intervention were younger, more likely to have presented with seizure, and less likely to have large bAVMs than patients managed conservatively. During a median follow-up of 6.9 years (94% completeness), the rate of progression to the primary outcome was lower with conservative management during the first 4 years of follow-up (36 vs 39 events; 9.5 vs 9.8 per 100 person-years; adjusted hazard ratio, 0.59; 95% CI, 0.35-0.99), but rates were similar thereafter. The rate of the secondary outcome was lower with conservative management during 12 years of follow-up (14 vs 38 events; 1.6 vs 3.3 per 100 person-years; adjusted hazard ratio, 0.37; 95% CI, 0.19-0.72). CONCLUSIONS AND RELEVANCE: Among patients aged 16 years or older diagnosed as having unruptured bAVM, use of conservative management compared with intervention was associated with better clinical outcomes for up to 12 years. Longer follow-up is required to understand whether this association persists.

Accuracy of routinely collected hospital administrative discharge data and death certificate ICD-10 diagnostic coding in progressive supranuclear palsy and corticobasal syndrome: a systematic review and validation study.

BACKGROUND: We conducted a systematic review to identify existing ICD-10 coding validation studies in progressive supranuclear palsy and corticobasal syndrome [PSP/CBS]) and, in a new study, evaluated the accuracy of ICD-10 diagnostic codes for PSP/CBS in Scottish hospital inpatient and death certificate data. METHODS: Original studies that assessed the accuracy of specific ICD-10 diagnostic codes in PSP/CBS were sought. Separately, we estimated the positive predictive value (PPV) of specific codes for PSP/CBS in inpatient hospital data (SMR01, SMR04) compared to clinical diagnosis in four regions. Sensitivity was assessed in one region due to a concurrent prevalence study. For PSP, the consistency of the G23.1 code in inpatient and death certificate coding was evaluated across Scotland. RESULTS: No previous ICD-10 validation studies were identified. 14,767 records (SMR01) and 1497 records (SMR04) were assigned the candidate ICD-10 diagnostic codes between February 2011 and July 2019. The best PPV was achieved with G23.1 (1.00, 95% CI 0.93-1.00) in PSP and G23.9 in CBS (0.20, 95% CI 0.04-0.62). The sensitivity of G23.1 for PSP was 0.52 (95% CI 0.33-0.70) and G31.8 for CBS was 0.17 (95% CI 0.05-0.45). Only 38.1% of deceased G23.1 hospital-coded cases also had this coding on their death certificate: the majority (49.0%) erroneously assigned the G12.2 code. DISCUSSION: The high G23.1 PPV in inpatient data shows it is a useful tool for PSP case ascertainment, but death certificate coding is inaccurate. The PPV and sensitivity of existing ICD-10 codes for CBS are poor due to a lack of a specific code.

Total Patient Delay: A Comparison of Patient and Clinician/Health System Delays in the Diagnosis of Progressive Supranuclear Palsy and Corticobasal Syndrome.

BACKGROUND: Early diagnosis in progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) is important for clinical care and key to developing successful disease-modifying agents. The patient-dependent phases of decision-making made before contact with a healthcare professional have been inadequately studied. OBJECTIVES: To evaluate the patient-dependent phases of decision-making from symptom onset, comparing this to clinician and/or health system delays within the overall diagnostic pathway. METHODS: Using the Anderson General Model of Total Patient Delay and a mixed-methods approach in participants with PSP/CBS and their caregivers recruited to the Scottish PSP and CBS cohort, we quantified and evaluated the determinants of "appraisal", "illness," and "behavioral" delay, comparing this to the clinician and/or health system delays ("treatment" delay) within the overall time from symptom onset to diagnosis. RESULTS: The time from index symptom onset to diagnosis was 3.26 (interquartile range [IQR] = 2.42, 4.75) years in PSP and 2.58 (IQR = 1.69, 4.08) years in CBS. Patient appraisal delay was 24 (IQR = 6, 60) weeks in PSP and 8 (IQR = 5, 24) weeks in CBS, illness delay 0 (IQR = -14, 0) weeks in PSP and 0 (IQR = -4, 0) weeks in CBS, with little perceived behavioral delay. Determinants of delay included the non-specificity of symptoms, normalization of symptoms within the context of age or normal physiological variability, and the extent of insight into new somatic symptoms. CONCLUSIONS: Although patient appraisal delay contributes to overall diagnostic delay in PSP/CBS, the greater proportion of overall diagnostic delay arises after contact with a healthcare professional (treatment delay).

Incidence and risk factors of institutionalisation in Parkinson's disease and atypical parkinsonism.

INTRODUCTION: The basic epidemiology of institutionalisation (the need for long-term care in an institution) in parkinsonism is unclear. We aimed to identify the incidence of, and risk factors for, institutionalisation in Parkinson's disease (PD) and atypical parkinsonism (AP). METHODS: We analysed data from a prospective population-based incidence cohort of parkinsonism in North-East Scotland (the PINE study). 556 newly-diagnosed participants (PD, N = 200; AP, N = 98; controls, N = 258), recruited between 2002 and 2009, were prospectively followed life-long with data collection on place of residence. We determined the incidence and baseline predictors of institutionalisation using Cox regression. RESULTS: The median follow-up time was 9.3, 4.4, and 10.8 years in PD, AP, and controls respectively. 70 (35 %) PD, 53 (54 %) AP, and 43 (16 %) controls became institutionalised. The incidence rates of institutionalisation in PD, AP, and controls were 5.1, 20.8, and 1.8 per 100 person-years respectively. The median time to institutionalisation was 11.8 years in PD and 3.5 years in AP. Multivariable Cox regression showed that AP (HR versus PD = 3.05 [95 % CI 1.90,4.91]), increasing age (HR for 10-year increase = 1.82 [95 % CI 1.40,2.36]), poorer cognition (HR for MMSE<24 versus MMSE>27 = 2.62 [95 % CI 1.45, 4.73]), more-severe parkinsonian impairment (UPDRS part 3) (HR for 10-point increase = 1.25 [95 % CI 1.05, 1.48]) were independently associated with higher hazards of institutionalisation. Sex, co-morbidity, smoking history, and living alone were not associated with institutionalisation. CONCLUSION: Institutionalisation is much more frequent in parkinsonism, particularly in AP, than in controls. AP, older age, severe parkinsonian impairment, and poorer cognition were independent baseline predictors of institutionalisation.

A systematic review of biomarkers for disease progression in Parkinson's disease.

BACKGROUND: Using surrogate biomarkers for disease progression as endpoints in neuroprotective clinical trials may help differentiate symptomatic effects of potential neuroprotective agents from true disease-modifying effects. A systematic review was undertaken to determine what biomarkers for disease progression in Parkinson's disease (PD) exist. METHODS: MEDLINE and EMBASE (1950-2010) were searched using five search strategies. Abstracts were assessed to identify papers meriting review in full. Studies of participants with idiopathic PD diagnosed by formal criteria or clearly described clinical means were included. We made no restriction on age, disease duration, drug treatment, or study design. We included studies which attempted to draw associations between any tests used to investigate disease progression and any clinical measures of disease progression. The electronic search was validated by hand-searching the two journals from which most included articles came. RESULTS: 183 studies were included: 163 (89%) cross-sectional, 20 (11%) longitudinal. The electronic search strategy had a sensitivity of 71.4% (95% CI 51.1-86.0) and a specificity of 97.1% (95% CI 96.5-97.7). In longitudinal studies median follow-up was 2.0 years (IQR 1.1-3.5). Included studies were generally poor quality--cross-sectional with small numbers of participants, applying excessive inclusion/exclusion criteria, with flawed methodologies and simplistic statistical analyses. CONCLUSION: We found insufficient evidence to recommend the use of any biomarker for disease progression in PD clinical trials, which may simply reflect the poor quality of research in this area. We therefore present a provisional 'roadmap' for conducting future disease progression biomarker studies, and recommend new quality criteria by which future studies may be judged.

Achieving proportionate governance review in Scotland: Threats and solutions.

The effectiveness of any healthcare-related research governance system is dependent on its ability to identify, challenge and change practices that compromise its ability to deliver timely, proportionate review. We present a case study outlining our experience of obtaining research ethics committee (REC) and Public Benefit and Privacy Panel (PBPP) for Health and Social Care approval to conduct a study which aimed to collect data on diagnostic and care pathways and determine the national prevalence of two rare diseases in Scotland. We discuss the threats posed to low-risk observational epidemiological research by disproportionate governance practices and propose practical solutions. In the context of increasing investment, the ever-increasing barriers to doing high-quality, low-risk epidemiological research using patient-identifiable information is concerning. Information governance committees, guided by clinical researchers, must step up as leaders in this area, making use of flexibilities and opportunities within the law.

The evolution of diagnosis from symptom onset to death in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) compared to Parkinson's disease (PD).

BACKGROUND: Misdiagnosis and delayed diagnosis in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are common. Few studies have systematically evaluated the diagnostic process from symptom onset to death in representative cohorts. METHODS: All PSP/CBD cases (n = 28/2) and age-sex matched Parkinson's disease (PD) cases (n = 30) were identified from a UK prospective incident Parkinsonism cohort. Medical and research records were reviewed to compare median times from first index symptom to key diagnostic milestones and the nature/timing of secondary care referral and review. RESULTS: Index symptoms were similar apart from more tremor in PD (p < 0.001) and more impaired balance (p = 0.008) and falls (p = 0.004) in PSP/CBD. PD was diagnosed a median 0.96 years after index symptom. In PSP/CBD the median times from index symptom to identifying parkinsonism and then including PSP/CBD in the differential diagnosis and the final diagnosis were 1.88, 3.41 and 4.03 years, respectively (all p < 0.001). Survival from symptom onset in PSP/CBD and PD was not significantly different (5.98 vs 6.85 years, p = 0.72). More diagnoses (p < 0.001) were considered in PSP/CBD. Prior to diagnosis, PSP/CBD patients had more recurrent emergency attendances (33.3% vs 10.0%, p = 0.01) and were referred to more specialities than PD (median 5 vs 2). Time to any outpatient referral (0.70 vs 0.03 years, p = 0.025) and to specialist movement disorder review (1.96 vs 0.57 years, p = 0.002) was longer in PSP/CBD. CONCLUSIONS: The duration and complexity of the diagnostic journey were greater in PSP/CBD than age-sex matched PD but can be improved. In this older cohort, there was little difference in survival from symptom onset in PSP/CBD and age-sex matched PD.

Progressive multifocal leukoencephalopathy associated with carbamazepine-induced immune dysfunction and recovery after carbamazepine cessation.

A patient with epilepsy on carbamazepine developed a rapidly progressive cerebellar syndrome. Serial MRI showed progressive posterior fossa T2/fluid attenuated inversion recovery hyperintensity with gadolinium enhancement. Standard cerebrospinal fluid (CSF) analysis was normal. Detection of John Cunningham virus DNA in the CSF confirmed progressive multifocal leukoencephalopathy (PML). The only evidence of immune disfunction was hypogammaglobulinaemia and longstanding lymphopenia. After cessation of carbamazepine, the lymphocyte count and immunoglobulin levels returned to normal and the PML resolved, with good clinical recovery. No specific treatments for PML were given. We hypothesise that PML in this case was due to carbamazepine-induced prolonged mild immunosuppression with reconstitution of the immune system after carbamazepine cessation, resulting in recovery from PML. Effects of anticonvulsants on immune function and infection risk may contribute to epilepsy-related morbidity and mortality. Further investigation is needed to determine the frequency of immune dysfunction and infections in patients treated with anticonvulsants such as carbamazepine and whether interventions could reduce infection risk.

Cognitive and Motor Decline in Dementia with Lewy Bodies and Parkinson's Disease Dementia.

Background: There is a need to better understand the rate of cognitive and motor decline of Dementia with Lewy bodies (DLB) and Parkinson's disease Dementia (PDD). Objectives: To compare the rate of cognitive and motor decline in patients with DLB and PDD from the E-DLB Consortium and the Parkinson's Incidence Cohorts Collaboration (PICC) Cohorts. Methods: The annual change in MMSE and MDS-UPDRS part III was estimated using linear mixed regression models in patients with at least one follow-up (DLB n = 837 and PDD n = 157). Results: When adjusting for confounders, we found no difference in the annual change in MMSE between DLB and PDD (-1.8 [95% CI -2.3, -1.3] vs. -1.9 [95% CI -2.6, -1.2] [P = 0.74]). MDS-UPDRS part III showed nearly identical annual changes (DLB 4.8 [95% CI 2.1, 7.5]) (PDD 4.8 [95% CI 2.7, 6.9], [P = 0.98]). Conclusions: DLB and PDD showed similar rates of cognitive and motor decline. This is relevant for future clinical trial designs.

Comparison of patient rated treatment response with measured improvement in Parkinson's disease.

BACKGROUND: A marked response to dopamine replacement therapy is important in supporting a diagnosis of idiopathic Parkinson's disease (PD). The aim of the study was to compare PD patients' subjective rating of improvement with measured improvement on a number of scales. METHODS: People with clinically defined PD were identified from a prospective long term follow-up study of incident parkinsonian patients. Changes in the Unified Parkinson's Disease Rating Scale (UPDRS) (activities of daily living and motor subsections), timed tests and Parkinson's Disease Questionnaire, full version, between assessments immediately before starting adequate dopamine replacement and the two subsequent follow-up assessments (mean 6 and 12 months after baseline) were calculated. These were compared with the patients' own subjective ratings of improvement (nil, slight, moderate, good, excellent). RESULTS: 133 patients were included (mean age 71 years, 56% men). Thirty-eight patients were treated with a dopamine agonist and 95 with l-dopa (median l-dopa equivalent dose 300 mg). Most patients showed improvements in their measured scores but there was no statistically significant association between these scores and the patient subjective response, except for the motor UPDRS at the first follow-up. A third of those who showed no improvement in their motor UPDRS at the first follow-up rated their improvement as moderate or better, while 29% of those whose motor UPDRS improved by over 50% said they had no or slight improvement. CONCLUSION: PD patients' subjective ratings of their degree of improvement often do not accurately reflect the degree of objective change in parkinsonian impairment or disability. Clinicians should record a simple measure of motor impairment before and after treatment to assess treatment response more accurately.

A new prevalence study of multiple sclerosis in Orkney, Shetland and Aberdeen city.

BACKGROUND: 30 years ago very high multiple sclerosis (MS) prevalence rates were recorded in northern Scotland. A prevalence study was repeated in Aberdeen, Orkney and Shetland to see if prevalence rates had changed, assess which factors affect prevalence and record disability status. METHODS: Hospital, general practice and laboratory records were searched to identify prevalent MS patients (alive and registered with a participating general practice on 24 September 2009). Records were reviewed to confirm diagnoses applying Poser definite and probable and McDonald diagnostic criteria. Disability status (Expanded Disability Status Scale) was recorded from records and questionnaires. Rates were standardised to the Scottish population. RESULTS: 590 patients were found (Aberdeen 442, Orkney 82, Shetland 66). Mean age and disease duration were 53 and 19.4 years, respectively. The standardised prevalence rates for Poser probable/definite MS per 100, 000 were: combined area 248 (95% CI 229 to 269), Orkney 402 (95% CI 319 to 500), Shetland 295 (95% CI 229 to 375) and Aberdeen 229 (95% CI 208 to 250). McDonald diagnostic criteria gave a lower prevalence (202, 95% CI 198 to 206). Prevalence was highest in women (2.55:1, 95% CI 2.26 to 2.89) with about 1 in 170 women in Orkney affected. Prevalence was lowest in the most deprived socioeconomic group. 45% had significant disability (Expanded Disability Status Scale ≥6). CONCLUSION: The prevalence of MS has increased in the overall area, most markedly in Orkney, then Shetland, over the past 30 years. This increase could be due to a number of factors, but rising incidence as reflected by a rising sex ratio, influenced by gene-environment interaction, is the most likely. Orkney has the highest prevalence rate recorded worldwide.

Systematic Review of Prevalence Studies of Progressive Supranuclear Palsy and Corticobasal Syndrome.

Background: High-quality prevalence studies are important in estimating the burden of disease in a population, thus informing priority setting, resource allocation, delivery, and use of health services. Objectives: This study was undertaken to systematically review the methods and results of previous prevalence studies of progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) and make recommendations for future studies. Methods: A total of 2 authors independently identified original articles that described the prevalence of PSP or CBS using several comprehensive and overlapping search strategies, assessed study quality, and extracted relevant data. Descriptive and pooled analyses were performed as appropriate. Results: A total of 16 studies were identified in PSP and 9 studies in CBS, with highly heterogeneous methods of case definition, identification, and verification in identified studies. Few studies were deemed of necessary quality or methodological homogeneity to justify a full meta-analysis. In addition, few studies reported age- and sex-stratified results. The best 3 prevalence studies in PSP gave a pooled rate of 7.1 per 100,000 per year, whereas the pooled rate in 2 CBS studies was roughly 3 times lower at 2.3 per 100,000 per year. Based on crude rates, there was little evidence to suggest clear sex differences in the prevalence of PSP or CBS or that the prevalence of PSP had increased over time, but some evidence to suggest that prevalence may increase with increasing age. Conclusion: Given the paucity of prevalence studies in PSP and CBS, further high-quality prevalence studies are necessary.

Association of GBA Genotype With Motor and Functional Decline in Patients With Newly Diagnosed Parkinson Disease.

OBJECTIVE: To establish the significance of glucocerebrosidase gene (GBA) carrier status on motor impairment in a large cohort of patients with incident Parkinson disease (PD). METHODS: Three European population-based studies followed 528 patients with PD from diagnosis. A total of 440 with genomic DNA from baseline were assessed for GBA variants. We evaluated motor and functional impairment annually using the Unified Parkinson's Disease Rating Scale (UPDRS) motor and activities of daily living (ADL) sections. Differential effects of classes of GBA variants on disease progression were evaluated using mixed random and fixed effects models. RESULTS: A total of 387 patients with idiopathic disease (age at baseline 70.3 ± 9.5 years; 60.2% male) and 53 GBA carriers (age at baseline 66.8 ± 10.1 years; 64.2% male) were included. The motor profile of the groups was clinically indistinguishable at diagnosis. GBA carriers showed faster annual increase in UPDRS scores measuring ADL (1.5 point per year, 95% confidence interval [CI] 1.1-2.0) and motor symptoms (2.2 points per year, 95% CI 1.3-3.1) compared to noncarriers (ADL, 1.0 point per year, 95% CI 0.9-1.1, p = 0.003; motor, 1.3 point per year, 95% CI 1.1-1.6, p = 0.007). Simulations of clinical trial designs showed that recruiting only GBA carriers can reduce trial size by up to 65% compared to a trial recruiting all patients with PD. CONCLUSION: GBA variants are linked to a more aggressive motor disease course over 7 years from diagnosis in patients with PD. A better understanding of PD progression in genetic subpopulations may improve disease management and has direct implications for improving the design of clinical trials.