Time Of Parkinson's Disease Diagnosis Research Articles

A Prescription for Wellness in Early PD: Just What the Doctor Ordered.

Being diagnosed with a neurodegenerative disease is a life-changing event and a critical time to help patients cope and move forward in a proactive way. Historically, the main focus of Parkinson's disease (PD) treatment has been on the motor features with limited attention given to non-motor and mental health sequelae, which have the most impact on quality of life. Although depression and anxiety have been described at the time of PD diagnosis, demoralization, intolerance of uncertainty, decreased self-efficacy, stigma and loneliness can also present and have negative effects on the trajectory of the disease. Hence, understanding the psychological impact of the diagnosis and how to provide better counselling at this critical time point may be the key to a better long-term trajectory and quality of life. There has been a paradigm shift in the treatment of chronic illness moving beyond the medical model, which focuses on fighting illness with the physician being in charge of the treatment process and the patient being the passive recipient, toward a more holistic (i.e., physical, psychological, social, and spiritual health) biopsychosocial approach that emphasizes behavioral factors with the patient being an active collaborator in their treatment. Hence, we propose that fostering resilience, social support, and psychological flexibility offer promise toward attenuating negative reactions and improving overall well-being. Through a proactive wellness approach incorporating lifestyle choices, people with PD (PwP) can not only achieve improved states of health, well-being, and quality of life, but actually thrive.

GCase activity and long‐term risk of dementia in Parkinson’s disease

AbstractBackgroundClinically, patients with Parkinson disease (PD) carrying a mutation in the glucocerebrosidase (GCase) gene (GBA) are at higher risk of dementia, suggesting that GCase dysfunction may contribute to a more severe disease course, although evidence is lacking. We aimed to discover if cerebrospinal fluid (CSF) GCase activity is altered in newly diagnosed PD patients and if GCase activity at diagnosis predicts the future development of dementia.MethodWe measured CSF GCase activity in 117 PD patients from the Norwegian ParkWest study, a population‐based study of incident PD with 10 years of biannual, prospective follow up, and 50 control subjects without neurological disease. PD dementia diagnosis was set according to established clinical criteria. Parametric accelerated failure time models were applied to analyze the association of GCase activity at the time of PD diagnosis with dementia free survival.ResultGCase activity was reduced in PD patients with (0.92±0.40 mU/mg) or without GBA mutations (1.00±0.37 mU/mg) compared to controls (1.20±0.35 mU/mg). GCase activity at the time of diagnosis was lower in PD patients who developed dementia within 10 years (n=41, 35%) than in those who remained free of dementia (p = 0.001). Further, patients in the lowest tertile of GCase activity at PD diagnosis were at 3‐fold increased risk of developing dementia in the next ten years (HR 3.10; 95% 0.72 to 4.68; P= .014; Figure), a finding that was also independent of GBA carrier status.ConclusionThis is the first study to show both that GCase dysfunction is evident in idiopathic PD at the time of diagnosis and that low GCase activity is associated with greater risk of developing dementia over the next ten years. GCase‐targeting compounds are among the most promising strategies towards disease‐modifying treatments in PD, and evidence for the association of CSF GCase activity with disease progression, independent of GBA mutation status, will have important implications for clinical trial design and patient management.

Association of CSF Glucocerebrosidase Activity With the Risk of Incident Dementia in Patients With Parkinson Disease.

Variations in the glucocerebrosidase gene (GBA) are common risk factors for Parkinson disease (PD) and dementia in PD (PDD) and cause a reduction in the activity of the lysosomal enzyme glucocerebrosidase (GCase). It is anticipated that GCase dysfunction might contribute to a more malignant disease course and predict cognitive impairment in PD, although evidence is lacking. We aimed to discover whether CSF GCase activity is altered in newly diagnosed patients with PD and associated with future development of dementia. Patients with PD were participants of the ongoing population-based longitudinal ParkWest study in Southwestern Norway and were followed prospectively for up to 10 years. CSF was collected at diagnosis, and GBA carrier status was obtained. Control samples were from persons without neurodegenerative disorders. GCase activity was measured using a validated assay. PD dementia diagnosis was set according to the Movement Disorder Society criteria, and parametric accelerated failure time models were applied to analyze the association of GCase activity with dementia-free survival. This study enrolled 117 patients with PD (mean age 67.2 years, including 12 GBA non-synonymous variant carriers) and 50 control participants (mean age 64 years). At the time of diagnosis, GCase activity was reduced in patients with PD with (mean ± SD, 0.92 ± 0.40 mU/mg, n = 12) or without GBA variations (1.00 ± 0.37 mU/mg, n = 105) compared with controls (1.20 ± 0.35, n = 50). GCase activity at the time of diagnosis was lower in patients with PD who developed dementia within 10 years (0.85 ± 0.27 mU/mg, n = 41) than in those who did not (1.07 ± 0.40 mU/mg, n = 76, p = 0.001). A 0.1-unit reduction in baseline GCase activity was associated with a faster development of PDD (hazard ratio 1.15, 95% CI 1.03-1.28, p = 0.014). The association of early CSF GCase activity with long-term progression to PD dementia will have important implications for the design of clinical trials for GCase targeting therapies and patient management. This study provides Class III evidence that reduced CSF GCase activity at the time of PD diagnosis is associated with an increased risk for later development of PDD.

Identifying the white matter structural network of motor reserve in early Parkinson's disease

IntroductionMotor reserve refers to the individual capacity to cope with nigrostriatal dopamine depletion in Parkinson's disease (PD). This study aimed to explore the white matter structural network associated with motor reserve in patients with newly diagnosed PD. MethodsA total of 238 patients with early-stage drug-naïve PD who underwent 18F-FP-CIT PET and brain MRI scans at initial assessment were enrolled. We estimated individual motor reserve based on the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) scores and dopamine transporter availability in the posterior putamen using a residual model. Then, we performed threshold-free network-based statistics (TFNBS) analysis to identify the structural brain network associated with the estimated motor reserve. We also assessed the effect of the network connectivity strength on the longitudinal increase in levodopa-equivalent dose (LED). ResultsThe mean age at PD symptom onset was 69.10 ± 9.03 years and the mean UPDRS-III score at the time of PD diagnosis was 22.44 ± 9.72. TFNBS analysis identified a motor reserve-associated structural network whose nodes were mainly in the frontal region and cerebellum. Higher network strength (i.e., greater motor reserve) was associated with a slower longitudinal increase in LED during a 3-year follow-up period. ConclusionThe structural brain network is associated with motor reserve in patients with PD. Connectivity strength within the identified network indicates the individual's capacity to tolerate PD-related pathologies, which is maintained with disease progression and affects the long-term motor prognosis of PD.

Frailty in Parkinson's disease and its association with early dementia: A longitudinal study

IntroductionFrailty is recognized as a clinical condition associated with increased vulnerability for developing negative health outcomes but has been little studied in patients with Parkinson's disease (PD). Here, we investigated the risk of frailty in de novo PD patients and its association with subsequent development of dementia. MethodsWe conducted a three-year longitudinal population-based study of 192 drug-naive newly diagnosed PD patients and 172 controls (No-PD) matched for age, sex, and education. Frailty was measured using the frailty index (FI). Logistic regression models, adjusting for potential confounders, were conducted to assess the association between frailty at the time of PD diagnosis and the subsequent odds for developing PD dementia during follow-up. ResultsThe mean baseline FI score was higher in the PD (0.21 ± 0.10) than in the No-PD group (0.11 ± 0.07, p < 0.001). One-third of PD patients had high-FI (>0,25), compared to 5% in the no-PD group. Participants with PD had an increased risk to present frailty with an odds ratio (OR) of 6.68 (SE 2.70 IC 95% [3.15; 15.62], p-value <0.001) compared to the No-PD group. PD Participants with greater FI measured at baseline had increased odds of having dementia within three years of follow-up, after adjustment for age and sex (OR 2.91 SE 1.00 IC 95% [1.54; 5.99] p-value = 0.002). ConclusionFrailty is common in people with newly diagnosed PD and associated with increased odds for subsequent development of dementia in a three-year follow-up. This study emphasizes the prognostic importance of frailty in PD from the earliest clinical stages.

Higher vitamin B12 level at Parkinson's disease diagnosis is associated with lower risk of future dementia

IntroductionTo determine whether vitamin B12 level at Parkinson's disease (PD) diagnosis predicts time to develop dementia. MethodsWe utilized a population-based cohort of Parkinsonism patients to examine the relationship between serum vitamin B12 at the time of PD diagnosis and dementia risk. Receiver operating curves were calculated for vitamin B12 cutoffs maximizing sensitivity and specificity for determining who developed dementia. Time from Parkinsonism diagnosis to dementia, death, or censoring was calculated utilizing Kaplan-Meier analysis and Cox-proportional hazard models. ResultsPD patients who did not develop dementia had higher baseline levels of vitamin B12 at PD diagnosis (648.5 ng/L vs 452 ng/L, p < 0.05) than those who developed dementia. Dementia risk was significantly lower in the 3rd tertile compared with 2nd tertile and trended towards significance compared to the 1st tertile. Each 100 unit increase in vitamin B12 level had a hazard ratio of 0.31 (95% CI 0.44–0.95) for future dementia (p < 0.05). Vitamin B12 cutoff of <587 ng/L was 87% sensitive and 70% specific (AUC 0.79, 95% CI 0.60–0.98) distinguishing patients with dementia. PD patients with vitamin B12 levels <587 ng/L were 5.4 times more likely to develop dementia, with 50% having dementia within 5 years of PD diagnosis compared with 11% in those with a vitamin B12 level of ≥587 ng/L (p < 0.05). ConclusionHigher levels of serum vitamin B12 at PD diagnosis correlate with lower risk of future dementia. The role of vitamin B12 in the development of dementia among PD patients deserves further evaluation.

Effect of levodopa on cochlear mechanics and efferent auditory system of Parkinson's disease individuals.

To evaluate the effect of levodopa on cochlear dynamics and on the medial olivocochlear efferent pathway of idiopathic Parkinson's disease (PD) individuals. Individuals with and without PD, followed at a University Hospital, were submitted to Distortion Product Otoacoustic Emissions (DPOAE) and DPOAE Inhibitory Effect (OAEIE) in the presence of contralateral noise. Correlation measures between DPOAE and OAEIE results with Hoehn&Yahr (H&Y) stage, daily dose of levodopa and PD diagnosis period were established. Furthermore, electroacoustic measures were compared between individuals without and those with PD, stratified by dose of levodopa daily administered. Weak negative correlation between DPOAE amplitude and daily dose of levodopa was found, as well positive correlations between EIEOA with daily dose of levodopa and time of PD diagnosis, respectively. Higher DPOAE amplitude was found in individuals with PD using daily doses of levodopa ≤ 600 milligrams when compared to individuals without PD and those with PD using higher doses. EIEOA was lower in individuals using doses ≤ 600 milligrams, when compared to the other groups. Daily doses of levodopa up to 600 mg / day increase the cochlear mechanical-transducer responses in 2 and 3 kHz frequencies, while the action of olivocochlear efferent systems is reduced in this region.

Progressive Decline in Gray and White Matter Integrity in de novo Parkinson's Disease: An Analysis of Longitudinal Parkinson Progression Markers Initiative Diffusion Tensor Imaging Data.

Background: Progressive neuronal loss in neurodegenerative diseases such as Parkinson’s disease (PD) is associated with progressive degeneration of associated white matter tracts as measured by diffusion tensor imaging (DTI). These findings may have diagnostic and functional implications but their value in de novo PD remains unknown. Here we analyzed longitudinal DTI data from Parkinson’s Progression Markers Initiative de novo PD patients for changes over time relative to healthy control (HC) participants.Methods: Baseline and 1-year follow-up DTI MRI data from 71 PD patients and 45 HC PPMI participants were included in the analyses. Whole-brain fractional anisotropy (FA) and mean diffusivity (MD) images were compared for baseline group differences and group–by–time interactions. Baseline and 1-year changes in DTI values were correlated with changes in DTI measures and symptom severity, respectively.Results: At baseline, PD patients showed significantly increased FA in brainstem, cerebellar, anterior corpus callosal, inferior frontal and inferior fronto-occipital white matter and increased MD in primary sensorimotor and supplementary motor regions. Over 1 year PD patients showed a significantly stronger decline in FA compared to HC in the optic radiation and corpus callosum and parietal, occipital, posterior temporal, posterior thalamic, and vermis gray matter. Significant increases in MD were observed in white matter of the midbrain, optic radiation and corpus callosum, while gray matter of prefrontal, insular and posterior thalamic regions. Baseline brainstem FA white matter (WM) values predicted 1-year changes in FA white matter and MD gray matter values. White but not gray matter changes in both FA and MD were significantly associated with changes in symptom severity.Conclusion: Significant gray and white matter DTI alterations are observable at the time of PD diagnosis and expand in the first year of de novo PD to other cortical and white matter regions. This pattern of DTI changes is in line with preclinical and neuroanatomical studies suggesting that the increased spatial spread of alpha-synuclein neuropathology is the key mechanism of PD progression. Taken together, these findings suggest that DTI may serve as a sensitive biomarker of disease progression in early-stage PD.

Alzheimer disease associated variants in SORL1 accelerate dementia development in Parkinson disease

ObjectiveDementia in Parkinson disease (PD) is a common occurrence, and shows a marked overlap at a clinical and pathological level with Alzheimer’s disease (AD), suggesting they share underlying disease mechanisms. Genetic variants in SORL1 have been identified in patients with AD, but a possible role in other dementias is unknown. The aim of this study was to investigate whether common polymorphisms in SORL1 affect the risk of developing dementia in a population-based cohort of patients with incident PD. MethodsOne common, nonsynonymous SORL1 variant (rs2298813; A528T) was identified in whole exome sequencing data from 185 patients with PD from the Norwegian ParkWest study, who had been followed up to the 7-year visit after diagnosis. A528T was tested for association with PD risk, the development of dementia, and in a subset of patients (n = 103) for associations with established AD cerebrospinal fluid (CSF) biomarkers measured at the time of PD diagnosis. ResultsWe found an association of A528T carrier status with increased risk of developing PD dementia (HR 2.31; 95% CI 1.09–4.90; p = 0.03) compared to non-carriers. Additionally, A528T carrier status was associated with a reduced ratio of CSF β-amyloid 42 to p-Tau (p = 0.014) but no alterations in absolute AD marker levels (all p > 0.05) at the time of PD diagnosis. ConclusionOur results show the first association of the AD risk factor SORL1 with incident dementia in PD, providing new evidence that AD related disease mechanisms may contribute to dementia in a subset of patients with PD. Finding support for a shared etiology for AD and PD dementia provides new directions for research into treatments for these diseases.

Depression in Parkinson's disease: A case-control study

BackgroundTo evaluate the association between Parkinson’s disease (PD) prognosis and the patient’s onset of depression.MethodsA total of 353 patients with newly-diagnosed PD and a history of depression were enrolled. On the basis of the onset of depression before or after PD diagnosis, we divided participants into PD patients with pre- or post-diagnostic depression. Cox’s regression analysis was used to detect risks between the onset of depression and outcomes (including death, accidental injury, dementia, and aspiration pneumonia). The association between the onset of depression and levodopa equivalent dosage (LED) and cumulative equivalent dosage of antidepressants were assessed.ResultsPD patients with post-diagnostic depression were associated with significantly higher risks of dementia (adjusted HR = 2·01, p = 0·015), and were older (58·5 ± 17·7 vs. 53·7 ± 18·6, p = 0·020) at the time of PD diagnosis than PD patients with pre-diagnostic depression. The higher incident rate of accidental injury was also noted in PD patients with post-diagnostic depression (48·1 vs. 31·3/1000 person-years, HR = 1·60, p = 0·041), but no statistical significance was observed in the adjusted hazard ratio (HR) (HR = 1·52, p = 0·069). Otherwise, mortality, motor condition and severity of depression revealed no significant difference between PD patients with pre-diagnostic and post-diagnostic depression.ConclusionPD patients with post-diagnostic depression had higher incidence of dementia, implying different onset time of depression could be associated with different subtypes and spreading routes which should be examined in follow-up studies.

Olfactory dysfunction and dementia in newly diagnosed patients with Parkinson's disease

IntroductionStudies report that up to 90% of patients with idiopathic Parkinson's disease (PD) have olfactory dysfunction (hyposmia). Hyposmia has also been connected to cognitive impairment and dementia in PD, but no studies of newly diagnosed patients followed longer than three years exists. The present study investigates the prevalence of olfactory dysfunction at PD diagnosis, how it evolves over time and whether hyposmia increases the risk of dementia in Parkinson's disease. MethodsOlfactory function was assessed with Brief Smell Identification Test (B-SIT) in 125 newly diagnosed patients with PD. They were followed for a maximum of 10 years (median six years) with extensive investigations at baseline, 12, 36, 60 and 96 months. Patients with B-SIT<9 were considered hyposmic. ResultsHyposmia was found in 73% of the patients at diagnosis. During the follow up period of ten years 42 (46%) patients with hyposmia at baseline developed dementia compared to seven (21%) of the normosmic patients. Cox proportional hazards model showed that hyposmia at baseline (controlled for age, gender, UPDRS III and Mild Cognitive Impairment) increased the risk of developing dementia (hazard ratio (95%CI): 3.29 (1.44–7.52), p = 0.005). Only one of 22 patients with normal cognition and normal olfaction at baseline developed dementia. ConclusionsOlfactory dysfunction was common at the time of PD diagnosis and increased the risk of dementia up to ten years after PD diagnosis regardless of baseline cognitive function. Normal olfaction together with normal cognition at baseline predicted a benign cognitive course up to ten years after diagnosis.

The impact of early versus late levodopa administration.

Long-term levodopa therapy in patients with Parkinson's disease (PD) is associated with motor complications including motor fluctuations (MF) and levodopa-induced dyskinesias (LID). The time to appearance of MF and LID is apparently related to both the timing and the duration of levodopa therapy, but is highly variable. We performed a retrospective analysis of all levodopa-treated PD patients to explore the effect of time from PD onset to levodopa initiation on time to MF or LID. We used a Cox multivariate regression model after stratifying patients into four quartiles, according to the time to levodopa initiation. Data from 170 PD patients (117 males, age at onset: 65.1±11.6years, time to levodopa treatment: 23.8±28.4months) was included in the analysis. Early levodopa administration was associated with a shorter time from diagnosis to both MF (p<0.001) and LID (p=0.001). The hazard ratio to develop MF and LID from the time of PD diagnosis was 2.48 (p<0.001) and 2.71 (p=0.002), respectively. In our population, we found that delaying levodopa administration was associated with a longer time to the appearance of motor complications after diagnosis. While disease duration is the most important determinant of the onset of motor complications, delaying levodopa could prolong the 'complication-free' period.

Intake of vitamin B before onset of Parkinson's disease and atypical parkinsonism and olfactory function at the time of diagnosis.

To investigate whether vitamin-B density in the diet 2-8 years before diagnosis is associated with olfactory function at the time of diagnosis. This prospective nested case-control study included patients with Parkinson's disease (PD), multiple system atrophy and progressive supranuclear paralysis identified between 2004 and 2009 in the county of Västerbotten in northern Sweden. The case database (NYPUM study; Newly Diagnosed Parkinson in Umeå; n=147) was cross-linked to the Northern Sweden Health and Disease Study (NSHDS). Identified patients (n=96) and controls (n=375) were matched for sex, age, year of health survey, sub-cohort and geographical area. Dietary intake was assessed by a food frequency questionnaire, and the brief smell identification test (B-SIT) was used to measure olfactory function at the time of diagnosis. There was no difference in vitamin-B or any other macro- or micro-nutrient densities, energy intake or body mass index (kg/m2; BMI) between patients and controls at baseline at the time of the healthcare survey. A lower thiamin and folate density, amount per 1 megajoule, was reported in patients who scored below median on B-SIT (<7) when compared with that in patients who scored ⩾7 at the time of diagnosis. After adjusting for age, sex and BMI using linear and logistic regressions, an even stronger association was found between thiamin density and olfactory function. A low thiamin and folate density in the reported diet, 2-8 years before PD diagnosis, was significantly associated with olfactory dysfunction at the time of PD diagnosis.

A Four-Year Longitudinal Study on Restless Legs Syndrome in Parkinson Disease.

Restless legs syndrome (RLS) prevalence estimates range from 0% to 52% in Parkinson disease (PD), but the causal relationship between the two disorders is still debated. The present study aims to evaluate RLS prevalence in de novo PD subjects, its incidence during the first 4 years from diagnosis, and possible relationships with clinical, laboratory, and neuroradiological data. One hundred nine newly diagnosed, drug-naïve PD subjects were evaluated at the time of PD diagnosis, and after 2- and 4-years. RLS diagnosis was performed with the RLS Diagnostic Index at each visit. Motor features, additional non-motor symptoms (NMS), and concomitant dopaminergic and nondopaminergic treatments were also gathered. Moreover, at baseline, 65 subjects were randomly selected to undergo a FP-CIT SPECT to study dopamine transporter availability. RLS prevalence rose from 4.6% at baseline evaluation to 6.5% after 2 years and to 16.3% after 4 years (P = 0.007). A multinomial logistic stepwise regression model selected NMS Questionnaire items more likely to be associated with RLS at diagnosis (insomnia, OR = 15.555; P = 0.040) and with occurrence of RLS during follow-up (dizziness, OR = 1.153; P = 0.022; and daytime sleepiness; OR = 9.557; P = 0.001), as compared to patients without RLS. Older age was more likely associated to increased RLS occurrence during follow-up in a random effect logistic regression model (OR = 1.187; P = 0.036). A multinomial logistic stepwise model found increased dopaminergic transporter availability of affected caudate and putamen to be more likely associated with RLS presence at diagnosis (n = 5; OR = 75.711; P = 0.077), and RLS occurrence during follow-up (n = 16; OR = 12.004; P = 0.059), respectively, as compared to patients without RLS (n = 88). RLS is present since PD diagnosis, and increases in prevalence during the course of PD. PD subjects with RLS have higher age at PD onset, more preserved dopaminergic pathways, and worse sleep and cardiovascular disturbances.

Epidemiology of early-onset Parkinson's disease in Finland.

The contribution of genetic causes to Parkinson's disease (PD) is strongest in early-onset cases. We ascertained a nationwide cohort of patients in order to study the genetic epidemiology of early-onset PD (EOPD) in Finland. By means of a search in a national database we ascertained all patients with EOPD. These patients had become eligible for reimbursement of PD drugs between the years 1995-2006 and were <55 years of age at the time of PD diagnosis. A total of 441 patients consented and provided clinical and genealogical information. The incidence of EOPD increased 1.7-fold between the years 1995-2006, the mean annual incidence being 3.3/100,000. Fifty-two patients (11.8%) reported an affected first-degree relative. The birthplaces of patients with PD among first-degree relatives were clustered in certain regions in the southwestern and western coastal provinces of Finland and in the eastern province of Savo. Furthermore, the distance between the birthplaces of the patients' parents was smaller for patients, who had first-degree relatives with PD than for patients with no family history of PD. Our data suggest that the incidence of EOPD is increasing. The birthplaces of patients with PD among first-degree relatives were clustered in certain provinces of Finland suggesting that monogenic forms of PD or genetic susceptibility of PD are present in the population.

Mild Parkinsonian Signs in the Elderly – Is There an Association with PD? Crossectional Findings in 992 Individuals

BackgroundMild parkinsonian signs (MPS) are common in the elderly population, and have been associated with vascular diseases, mild cognitive impairment and dementia; however their relation to Parkinson's disease (PD) is unclear. Hypothesizing that individuals with MPS may reflect a pre-stage of PD, i.e. a stage in which the nigrostriatal system is already affected although to a milder degree than at the time of PD diagnosis, aim of this study was to evaluate the similarities between MPS and PD.MethodsThe TREND study is a prospective cross-sectional cohort study in individuals >50 years with biennial assessments designed to identify markers for an earlier diagnosis of Parkinson's and Alzheimer's disease. For this substudy 992 individuals were included for analyses (892 controls, 73 MPS individuals, 27 PD patients). Parameters defining risk of PD (sex, age, positive family history), prodromal markers (hyposmia, REM sleep behavior disorder, depression and autonomic failure) as well as quantitative fine motor, axial motor and cognitive parameters were compared between the three cohorts.ResultsAs expected, PD patients differed from controls with regard to 12 of 15 of the assessed parameters. MPS individuals differed significantly from controls in 12 of the PD-associated parameters, but differed from PD only in 5 parameters.ConclusionThis study shows that individuals with MPS share many prodromal and clinical markers of PD with PD patients, implying that either a common dynamic process or similar constitutional factors occur in MPS individuals and PD patients.

Prevalence of malnutrition in Parkinson's disease: a systematic review

Parkinson's disease (PD) patients may be at higher risk of malnutrition because of the symptoms associated with the disease and the side effects of the medication used to manage it. A decline in nutritional status is associated with many adverse outcomes related to health and quality of life. It is not clear, however, to what extent this population is currently affected by malnutrition. The objective of this review was to systematically assess the methodology and outcomes of studies reporting the prevalence of malnutrition in PD patients. Studies that attempted to classify participants with PD into nutritional risk and/or malnutrition categories using body mass index, weight change, anthropometric measures, and nutritional screening and assessment scores were included. The prevalence of malnutrition ranged from 0% to 24% in PD patients, while 3-60% of PD patients were reported to be at risk of malnutrition. There was a large degree of variation among studies in the methods chosen, the definition of malnutrition using those methods, and the detail in which the methodological protocols were reported. The true extent of malnutrition in the PD population has yet to be accurately quantified. It is important, however, to screen for malnutrition at the time of PD diagnosis.

A Prospective Cohort Study of Cancer Incidence Following the Diagnosis of Parkinson's Disease

Prior studies suggest a decreased risk of cancer among patients with Parkinson's disease (PD). Matched cohort analysis among the 22,071 participants in the Physician's Health Study. A total of 487 incident cases of PD without preceding cancer were identified by self-report. Each PD case was matched by age to a reference participant who was alive and cancer free at the time of PD diagnosis. Both cohorts were followed for incident cancer. We used proportional hazards models to calculate adjusted relative risks (RR) for cancer. A total of 121 cancers were confirmed during a median follow-up of 5.2 years (PD) and 5.9 years (reference). Those with PD developed less cancer (11.0% versus 14.0%), with an adjusted RR of 0.85 [95% confidence interval (95% CI), 0.59-1.22]. Reduced risk was present for smoking-related cancers such as lung (RR, 0.32), colorectal (RR, 0.54), and bladder (RR, 0.68), as well as for most non-smoking-related cancers such as prostate cancer (RR, 0.74). In contrast, PD patients were at significantly increased risk (RR, 6.15; 95% CI, 1.77-21.37) for melanoma. PD patients who smoked were at reduced risk for smoking-related cancer (RR, 0.33; 95% CI, 0.12-0.92), whereas nonsmokers with PD were at increased risk (RR, 1.80; 95% CI, 0.60-5.39). This interaction was statistically significant (P(interaction) = 0.02). Our results suggest a decreased incidence of most cancers in patients with PD. PD patients had a significantly increased risk of malignant melanoma, a finding consistent with prior studies. We confirmed an interaction between smoking and the relationship of PD to smoking-related cancer that may fit the pattern of a gene-environment interaction.

Evolution of cognitive dysfunction in an incident Parkinson's disease cohort

We have previously performed detailed clinical and neuropsychological assessments in a community-based cohort of patients with newly diagnosed parkinsonism, and through analysis of a subcohort with idiopathic Parkinson's disease (PD), we have demonstrated that cognitive dysfunction occurs even at the time of PD diagnosis and is heterogeneous. Longitudinal follow-up of the cohort has now been performed to examine the evolution of cognitive dysfunction within the early years of the disease. One hundred and eighty (79%) eligible patients from the original cohort with parkinsonism were available for re-assessment at between 3 and 5 years from their initial baseline assessments. PD diagnoses were re-validated with repeated application of the UKPDS Brain Bank criteria in order to maximize sensitivity and specificity, following which a diagnosis of idiopathic PD was confirmed in 126 patients. Thirteen out of 126 (10%) had developed dementia at a mean (SD) of 3.5 (0.7) years from diagnosis, corresponding to an annual dementia incidence of 30.0 (16.4-52.9) per 1000 person-years. A further 57% of PD patients showed evidence of cognitive impairment, with frontostriatal deficits being most common amongst the non-demented group. However, the most important clinical predictors of global cognitive decline following correction for age were neuropsychological tasks with a more posterior cortical basis, including semantic fluency and ability to copy an intersecting pentagons figure, as well as a non-tremor dominant motor phenotype at the baseline assessment. This work clarifies the profile of cognitive dysfunction in early PD and demonstrates that the dementing process in this illness is heralded by both postural and gait dysfunction and cognitive deficits with a posterior cortical basis, reflecting probable non-dopaminergic cortical Lewy body pathology. Furthermore, given that these predictors of dementia are readily measurable within just a few minutes in a clinical setting, our work may ultimately have practical implications in terms of guiding prognosis in individual patients.