An examination of male-female differences in progression and mortality of Parkinson's disease

The Impact of Sex-Specific Survival on the Incidence of Dementia in Parkinson's Disease

OBJECTIVE

The aim of our study is to analyze sex-specific patterns of Parkinson's disease dementia (PDD) incidence. We are investigating the extent to which sex differences in survival after initial Parkinson's disease (PD) diagnosis influence differences in PDD risk among PD patients.

METHODS

We used a random sample of German longitudinal health claims data of persons ages 50+ (2004-2019; n = 250,000) and identified new PD cases ages 65+ who were followed-up for a PDD diagnosis or death between 2006 and 2017. We performed Cox and competing-risk regression models, with death as competing event, to calculate PDD hazard ratios (HR) adjusted for age at PD onset, PD severity as measured by the modified Hoehn and Yahr (HY) scale, comorbidities, and medications.

RESULTS

Of 2195 new PD cases, 602 people died before PDD and 750 people developed PDD by the end of 2017. The adjusted risk of PDD differs by sex, with men having a higher PDD risk than women. When accounting for death, men and women do not differ in their PDD risk (HR = 1.02, P = 0.770). Sex-specific analyses showed significant age and severity effects in women (age: HR = 1.05, P < 0.001; HY 3-5 vs. 0-2.5: HR = 1.46, P = 0.011), but not in men.

CONCLUSION

Older age at first PD diagnosis and higher disease severity increase PDD risk, but this association is attenuated for PD men when controlling for death. This implies that the most frail PD men die rapidly before receiving a dementia diagnosis, whereas women with PD survive at higher rates, regardless of their age at onset and disease severity. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Gender differences in motor and non-motor symptoms in individuals with mild-moderate Parkinson's disease

BACKGROUND

Parkinson's disease (PD) affects both men and women with documented gender differences across functional domains, with findings varying among reports. Knowledge regarding gender differences in PD for different geographic locations is important for further understanding of the disease and for developing personalized gender-specific PD assessment tools and therapies.

OBJECTIVE

This study aimed to examine gender differences in PD-related motor, motor-cognitive, cognitive, and psychosocial function in people with PD from the southern United States (US).

METHODS

199 (127 men and 72 women; M age: 69.08±8.94) individuals with mild-moderate idiopathic PD (Hoehn &Yahr (H&Y) Median = 2, stages I-III) from a large metro area in the southeastern US were included in this retrospective, cross-sectional study. Motor, motor-cognitive, cognitive, and psychosocial data were obtained using standardized and validated clinical tests. Univariate analyses were performed, adjusting for age and housing type.

RESULTS

After adjustment for age, housing, PD duration and fall rate, men exhibited statistically significantly greater motor (Movement Disorders Society (MDS)-Unified Parkinson Disease Rating Scale (UPDRS)-II) and non-motor (MDS-UPDRS-I) impact of PD, and more severe motor signs (MDS-UPDRS-III). Men exhibited worse PD-specific health-related quality of life related to mobility, activities of daily living, emotional well-being, cognitive impairment, communication, and more depressive symptoms. Men performed worse on a subtraction working memory task. Women had slower fast gait speed.

CONCLUSIONS

In the southeastern United States, men may experience worse PD-related quality of life and more depression than women. Many non-motor and motor variables that are not PD specific show no differences between genders in this cohort. These findings can contribute to the development of gender-sensitive assessment and rehabilitation policies and protocols for people with PD.

Outcomes of Patients With Parkinson Disease Undergoing Cervical Spine Surgery for Radiculopathy and Myelopathy With Minimum 2-Year Follow-up

STUDY DESIGN

This was a retrospective cohort analysis.

OBJECTIVE

To identify the impact of Parkinson disease (PD) on 2-year postoperative outcomes following cervical spine surgery (CSS).

SUMMARY OF BACKGROUND DATA

(PD) patients are prone to spine malalignment and surgical interventions, yet little is known regarding outcomes of CSS among PD patients.

MATERIALS AND METHODS

All patients from the Statewide Planning and Research Cooperative System with cervical radiculopathy or myelopathy who underwent CSS were included; among these, those with PD were identified. PD and non-PD patients (n=64 each) were 1:1 propensity score-matched by age, sex, race, surgical approach, and Deyo-Charlson Comorbidity Index (DCCI). Demographics, hospital-related parameters, and adverse postoperative outcomes were compared between cohorts. Logistic regression identified predictive factors for outcomes.

RESULTS

Overall, patient demographics were comparable between cohorts, except that DCCI was higher in PD patients (1.28 vs. 0.67, P=0.028). PD patients had lengthier mean hospital stays than non-PD patients (6.4 vs. 4.1 d, P=0.046). PD patients also incurred comparable total hospital expenses ($69,565 vs. $57,388, P=0.248). Individual medical complication rates were comparable between cohorts; though PD patients had higher rates of postoperative altered mental status (4.7% vs. 0%, P=0.08) and acute renal failure (10.9% vs. 3.1%, P=0.084), these differences were not significant. Yet, PD patients experienced higher rates of overall medical complications (35.9% vs. 18.8%, P=0.029). PD patients had comparable rates of individual and overall surgical complications. The PD cohort underwent higher reoperation rates (15.6% vs. 7.8%, P=0.169) compared with non-PD patients, though this difference was not significant. Of note, PD was not a significant predictor of overall 2-year complications (odds ratio=1.57, P=0.268) or reoperations (odds ratio=2.03, P=0.251).

CONCLUSION

Overall medical complication rates were higher in patients with PD, while individual medical complications as well as surgical complication and reoperation rates after elective CSS were similar in patients with and without PD, though PD patients required longer hospital stays. Importantly, a baseline diagnosis of PD was not significantly associated with adverse two-year medical and surgical complications. This data may improve counseling and risk-stratification for PD patients before CSS.

LEVEL OF EVIDENCE

Level III.

Sex specific cognitive differences in Parkinson disease

Parkinson disease (PD) is a progressive neurodegenerative disorder that is 1.5 times more common in males than in females. While motor progression tends to be more aggressive in males, little is known about sex difference in cognitive progression. We tested the hypothesis that there are sex differences in cognitive dysfunction in non-demented PD. We evaluated 84 participants (38 females) with PD and 59 controls (27 females) for demographic variables and cognitive function, including attention, working memory, executive function, and processing speed. Multivariate ANOVA revealed no significant differences between groups for demographic variables, including age, years of education, global cogntition, daytime sleepiness, predicted premorbid IQ, UPDRS score, PD phenotype, or disease duration. For cognitive variables, we found poorer performance in males versus females with PD for measures of executive function and processing speed, but no difference between male and female controls. Specifically, PD males showed greater deficits in Verbal Fluency (category fluency, category switching, and category switching accuracy), Color Word Interference (inhibition), and speed of processing (SDMT). There were no differences in measures of working memory or attention across sex and inconsistent findings for switching. Our data indicate that males with PD have significantly greater executive and processing speed impairments compared to females despite no differences in demographic variables or other measures of disease severity. Our findings are consistent with the steeper slope of disease progression reported in males with PD.

NADPH Oxidase Mediates Membrane Androgen Receptor-Induced Neurodegeneration

Oxidative stress (OS) is a common characteristic of several neurodegenerative disorders, including Parkinson disease (PD). PD is more prevalent in men than in women, indicating the possible involvement of androgens. Androgens can have either neuroprotective or neurodamaging effects, depending on the presence of OS. Specifically, in an OS environment, androgens via a membrane-associated androgen receptor (mAR) exacerbate OS-induced damage. To investigate the role of androgens on OS signaling and neurodegeneration, the effects of testosterone and androgen receptor activation on the major OS signaling cascades, the reduced form of NAD phosphate (NADPH) oxidase (NOX)1 and NOX2 and the Gαq/inositol trisphosphate receptor (InsP3R), were examined. To create an OS environment, an immortalized neuronal cell line was exposed to H2O2 prior to cell-permeable/cell-impermeable androgens. Different inhibitors were used to examine the role of G proteins, mAR, InsP3R, and NOX1/2 on OS generation and cell viability. Both testosterone and DHT/3-O-carboxymethyloxime (DHT)-BSA increased H2O2-induced OS and cell death, indicating the involvement of an mAR. Furthermore, classical AR antagonists did not block testosterone's negative effects in an OS environment. Because there are no known antagonists specific for mARs, an AR protein degrader, ASC-J9, was used to block mAR action. ASC-J9 blocked testosterone's negative effects. To determine OS-related signaling mediated by mAR, this study examined NOX1, NOX2, Gαq. NOX1, NOX2, and the Gαq complex with mAR. Only NOX inhibition blocked testosterone-induced cell loss and OS. No effects of blocking either Gαq or G protein activation were observed on testosterone's negative effects. These results indicate that androgen-induced OS is via the mAR-NOX complex and not the mAR-Gαq complex.

Early predictors of mortality in parkinsonism and Parkinson disease: A population-based study

Objective

To examine mortality and associated risk factors, including possible effects of mild cognitive impairment, imaging, and CSF abnormalities, in a community-based population with incident parkinsonism and Parkinson disease.

Methods

One hundred eighty-two patients with new-onset, idiopathic parkinsonism were diagnosed from January 2004 through April 2009, in a catchment area of 142,000 inhabitants in Sweden. Patients were comprehensively investigated according to a multimodal research protocol and followed prospectively for up to 13.5 years. A total of 109 patients died. Mortality rates in the general Swedish population were used to calculate standardized mortality ratio and expected survival, and Cox proportional hazard models were used to investigate independent predictors of mortality.

Results

The standardized mortality ratio for all patients was 1.84 (95% confidence interval 1.50–2.22, p < 0.001). Patients with atypical parkinsonism (multiple system atrophy or progressive supranuclear palsy) had the highest mortality. In early Parkinson disease, a mild cognitive impairment diagnosis, freezing of gait, hyposmia, reduced dopamine transporter activity in the caudate, and elevated leukocytes in the CSF were significantly associated with shorter survival.

Conclusion

Although patients presenting with idiopathic parkinsonism have reduced survival, the survival is highly dependent on the type and characteristics of the parkinsonian disorder. Patients with Parkinson disease presenting with normal cognitive function seem to have a largely normal life expectancy. The finding of a subtle CSF leukocytosis in patients with Parkinson disease with short survival may have clinical implications.

Estrogen receptor-β of microglia underlies sexual differentiation of neuronal protection via ginsenosides in mice brain

AIMS

Streptococcus pneumoniae infection in acute bacterial meningitis can lead to widespread brain damage and mortality. Inflammatory responses by immune cells in the brain are thought to determine the degree of brain injury. Yet, the mechanisms underlying host responses to pneumococcal meningitis are largely unknown. To explore host responses as a potential therapeutic target for preventing brain injury after pneumococcal meningitis.

METHODS

We evaluated signaling mechanisms that minimize neuronal damage caused by pneumococcal infection; specifically, we assessed pathways related to neuronal survival after enhancing estrogen receptor-β (ER-β) expression using a natural therapeutic substance known as ginsenoside Rb1 and Rg3 enhanced ginseng.

RESULTS

Tissue damage caused by bacterial infection was reduced in Rb1/Rg3-treated mice as a result of microglial activation and the inhibition of apoptosis. Furthermore, Rb1 upregulated the expression of brain-derived neurotrophic factor (BDNF) as well as anti-apoptotic factors including Bcl-2 and Bcl-xL. Using BV2 microglial cells in vitro, Rb1 treatment inhibited microglial apoptosis in a manner associated with JAK2/STAT5 phosphorylation.

CONCLUSION

After S. pneumoniae infection in mice, particularly in female mice, Rb1-containing ginseng increased bacterial clearance and survival. These findings inform our understanding of the host immune response to pneumococcal meningitis.

Clinical Profile of Chinese Long-Term Parkinson's Disease Survivors With 10 Years of Disease Duration and Beyond

Background

Parkinson’s disease (PD) patients with 10 years or more survival (PD-10) are not well characterized. The aim of this study was to evaluate the main issues facing PD-10 patients and identify factors that independently contributed to quality of life (QoL).

Methods

A group of 121 PD-10 patients recruited from outpatient clinics participated in this cross-sectional study. Data on demographic and clinical factors were collected. Multiple linear regression analyses were conducted to identify determinants of poor QoL.

Results

The entire PD-10 patients had disease duration ranging from 10 to 23 years, with 84.2% of the total cohort skewed to between 10 and 15 years’ duration. The PD-10 patients had great frequency of left-sided onset, increased motor and non-motor symptoms as well as inferior QoL. The more advanced stage of disease in PD-10 patients was associated with motor phenotype, freezing of gait, higher UPDRS sub-scores and levodopa equivalent dose, less balanced confidence, fatigue, anxiety, depression, reduced quality of life and worse Timed Up & Go performance. Self-reported mood symptoms, decreased balance confidence and reduced daily activities were the three factors most closely associated with poorer QoL, but excessive daytime sleepiness and long disease duration additionally contributed to the explanatory power.

Conclusions

This is the first report to investigate the clinical characteristics of Chinese PD-10 patients. Our study may elucidate an important clue for understanding PD-10 patients in clinical practice and identifying patients with PD at risk for reduced QoL.

Downregulation of blood serum microRNA 29 family in patients with Parkinson's disease

There is currently no reliable and easily applicable diagnostic marker for Parkinson’s disease (PD). The aims of the present study were to compare the expression profiles of the microRNA29 family (miR-29s) in blood serum from patients with PD with healthy controls and to clarify whether the expression of miR-29s is correlated with disease severity, duration or L-dopa therapy and whether expression depends on the gender and age of patients. The levels of blood serum miR-29s in 80 patients with PD and 80 unaffected controls were assessed by reverse transcription-quantitative real-time PCR. The PCR products were confirmed by cloning and sequencing. Additionally, the expression of miR-7 in the blood serum from PD patients and control subjects was assessed. Serum miR-29 levels were significantly downregulated in PD patients compared to healthy controls. The serum miR-29 levels in female PD patients were markedly higher than in male PD patients. The expression of serum miR-29a and miR-29c expression tended to decrease with disease severity. Moreover, we found that serum miR-7 levels did not differ between PD patients and control subjects. Therefore, the reduction of serum miR-29 levels, particularly miR-29a and miR-29c, warrants further investigation of its potential serving as biomarkers for PD.

Sex Differences in the Clinical Progression of Parkinson's Disease

OBJECTIVE

To describe characteristics of Parkinson's disease by sex and determine if differences in disease progression exist.

DESIGN

Longitudinal, observational study.

SETTING

Twenty-one National Parkinson Foundation Centers of Excellence.

PARTICIPANTS

People (N = 4,679; 63% men and 37% women) with idiopathic Parkinson's disease.

METHODS

Demographic and clinical data at enrollment and after 1 year were collected. We defined progression as a 1-year change in the following functional health outcome measures: (a) health-related quality of life (Parkinson's Disease Questionnaire-39), (b) Timed Up and Go test, (c) cognitive function, and (d) number of medications. We compared baseline characteristics between men and women. Then, linear regression models were built to assess the independent contribution of sex to progression.

RESULTS

At baseline, women were significantly more likely to be older and have greater disease severity and more comorbidities than men despite similar duration of disease. This finding corresponded to worse function as assessed by the Parkinson's Disease Questionnaire-39 and Timed Up and Go test but not to number of medications and cognitive function. After 1 year, declines across all functional measures except delayed recall occurred. No significant changes in Parkinson's Disease Questionnaire-39, Timed Up and Go, number of medications, or verbal fluency between men and women occurred. Women had a more significant improvement in delayed recall than men.

CONCLUSION

Numerous small baseline differences occurred between men and women with PD, although differences in markers of progression were few. Findings suggest that clinical manifestations and prognosis appear similar by sex under the same treatment conditions.

Parkinsonism Treatment: Part III—Update

OBJECTIVE:

The purpose of this review is to update clinicians with recent advances in the management of parkinsonism, including drug therapy, transplantation, and diet.

DATA SOURCES:

Pertinent articles were obtained from an English-language literature search using MEDLINE (1970–1991), Index Medicus (1987–1991), Current Contents (1990), and bibliographic reviews of review articles. Index terms included parkinsonism, selegiline, pergolide, vitamin E, and transplantation. Fifty-five articles (representing 85 percent of the complete literature search) were selected by multiple reviewers for their contribution to the stated purpose. Emphasis was placed on double-blind, placebo-controlled, and randomized studies. Data from cited articles were examined by multiple reviewers for support of their stated hypothesis and were included as background for justification of major points in this article; critical studies were abstracted in more detail.

RESULTS:

New therapeutic measures have been added to the treatment of parkinsonism. Selegiline, a monoamine oxidase inhibitor type B, has shown beneficial results, especially in early stages. Pergolide, a dopamine agonist, may be an efficacious alternative to bromocriptine resistance or intolerable adverse effects. Vitamin E may have protective antioxidant properties, but very few clinical data are available. Fetal tissue transplantation needs continued research and remains very controversial. Diet modification may maximize the results of therapy with exogenous dopamine therapy.

CONCLUSIONS:

Clinicians should familiarize themselves with new alternatives for the management of parkinsonism in order to be reliable consultants for both professional and lay persons.

Estrogen ameliorates microglial activation by inhibiting the Kir2.1 inward-rectifier K(+) channel

Microglial activation is implicated in the pathogenesis of Parkinson's disease (PD). Although the etiology of PD remains unclear, age and male gender are known PD risk factors. By comparing microglia and dopaminergic (DA) neurons in the substantia nigra (SN) of male and female mice of different ages, we found that the degrees of microglial activation and DA neuron loss increased with age in both genders, but were more pronounced in males, as were peripheral lipopolysaccharide (LPS)-induced microglial activation and DA neuron loss. A bilateral ovariectomy (OVX) eliminated the female-associated protection against age- and LPS-induced microglial activation, which suggests that ovary hormones are involved in gender-specific responses. Treating female mice with 17β-estradiol supplements reduced the age-associated microglial activation in OVX mice. Moreover, pretreating mouse BV2 microglial cells with 17β-estradiol inhibited LPS-induced elevation of Toll-like receptor 4, phosphorylated p38, and TNF-α levels. We then examined the effect of 17β-estradiol on inward-rectifier K(+) channel Kir2.1, a known regulator of microglial activation. We found that 17β-estradiol inhibited the Kir2.1 activity of BV2 cells by reducing the probability that the channel would be open. We conclude that age- and inflammation-associated microglial activation is attenuated by ovarian estrogen, because it inhibits Kir2.1.

Geographic Variations in the Prevalence Rates of Parkinson’s Disease in Alberta

Parkinson’s disease prevalence rates were examined for the Province of Alberta by age, sex and census division. Using the claims administrative data from the Alberta Health Care Insurance Plan, a cohort of all registered individuals (2.4 million) was extracted and followed for the five year period, April 1, 1984 to March 31, 1989. No new members were added to the cohort and an attrition rate averaging 6% per year was observed. The overall crude prevalence rates of 248.9 and 239.8 per 100,000 population were noted for males and females respectively. Both sexes were found to have a statistically significant variation across Alberta’s 19 census divisions. For males, examination of standardized morbidity ratios found a low risk of Parkinson’s disease associated with five census divisions, of which two contained Alberta’s two largest cities. An excess risk was associated with four primarily rural census divisions. Females, on the other hand, had a low risk associated with one rural census division and excess risk in four census divisions. The uneven distribution within Alberta offers support for an environmental theory of etiology which may be associated with rural living.

Sex Differences in Clinical Features of Early, Treated Parkinson's Disease

Introduction

To improve our understanding of sex differences in the clinical characteristics of Parkinson’s Disease, we sought to examine differences in the clinical features and disease severity of men and women with early treated Parkinson’s Disease (PD) enrolled in a large-scale clinical trial.

Methods

Analysis was performed of baseline data from the National Institutes of Health Exploratory Trials in Parkinson’s Disease (NET-PD) Long-term Study-1, a randomized, multi-center, double-blind, placebo-controlled study of 10 grams of oral creatine/day in individuals with early, treated PD. We compared mean age at symptom onset, age at PD diagnosis, and age at randomization between men and women using t-test statistics. Sex differences in clinical features were evaluated, including: symptoms at diagnosis (motor) and symptoms at randomization (motor, non-motor, and daily functioning).

Results

1,741 participants were enrolled (62.5% male). No differences were detected in mean age at PD onset, age at PD diagnosis, age at randomization, motor symptoms, or daily functioning between men and women. Differences in non-motor symptoms were observed, with women demonstrating better performance compared to men on SCOPA-COG (Z = 5.064, p<0.0001) and Symbol Digit Modality measures (Z = 5.221, p<0.0001).

Conclusions

Overall, men and women did not demonstrate differences in clinical motor features early in the course of PD. However, the differences observed in non-motor cognitive symptoms suggests further assessment of the influence of sex on non-motor symptoms in later stages of PD is warranted.

Gender-specific brain regional variation of neurons, endogenous estrogen, neuroinflammation and glial cells during rotenone-induced mouse model of Parkinson's disease

Rotenone (RT) produces reactive oxygen species (ROS) by inhibiting the mitochondrial electron transport chain; causing dopaminergic (DA) cell death in the substantia nigra (SN) and simulates other models of induced Parkinson's disease (PD). There is a sincere dearth of knowledge regarding the status of glial cells, neuroprotective estrogen and the status of neuroinflammatory TNF-α in the different brain regions in either sex during healthy, as well as during PD conditions. In the present study of RT-induced mouse model of PD, we have selected the frontal cortex (FC), hippocampus (HC) and SN from either sex of Swiss albino mice as these are the major regions involved during PD pathogenesis. During non pathogenic conditions, the ROS-scavenging enzyme activity varied among the brain regions and also in between genders. The number of DOPA decarboxylase-positive cells, astrocytes and microglia was similar in the respective regions of the brain in both the sexes. The level of proinflammatory cytokine TNF-α was same in the respective FC and HC in either sex except that of SN. The expression level of estrogen and its receptors varied among the three brain regions. During RT treatment, ROS-scavenging enzyme activities increased, DOPA decarboxylase-positive neurons and fibers in DA as well as in norepinephrinergic (NE) systems become degenerated, number of astrocytes decreased and microglial cells increased in those specific brain regions in either of the sexes except in the SN region of males where astrocyte number remained unaltered and microglial cell percentage decreased. TNF-α increased in the FC and SN but remained unaltered in the HC of both sexes. Estradiol level decreased in the HC and SN but the level unevenly varied in the FC. Similarly, the estrogen bound and nuclear-cytosolic receptor α and β also varied differentially among the brain regions of the two sexes. Therefore our present study depicts that there exists a clear variation of neuronal and astroglial cell population, estrogen and its receptor levels in different brain regions of both the sexes during control and RT-treated pathogenic condition and these variations have major implication in PD pathogenesis and progression.

Mortality in levodopa-treated Parkinson's disease

Parkinson's disease (PD) is associated with increased mortality despite many advances in treatment. Following the introduction of levodopa in the late 1960's, many studies reported improved or normalized mortality rates in PD. Despite the remarkable symptomatic benefits provided by levodopa, multiple recent studies have demonstrated that PD patients continue to die at a rate in excess of their peers. We undertook this retrospective study of 211 deceased PD patients to determine the factors associated with mortality in levodopa-treated PD. Our findings confirm that PD is associated with increased mortality in both men and women. Unlike the majority of other mortality studies, we found that women have a greater reduction in lifespan compared to men. We also found that patients with early onset PD (onset at the age of 50 or before) have reduced survival relative to PD patients with later ages of onset. A final important finding is that survival is equal in PD patients treated with levodopa early (within 2 years or less of PD onset) versus later.

Deep brain stimulation improves survival in severe Parkinson's disease

OBJECTIVES

Levodopa and other dopaminergic treatments have not had the expected effect on survival in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to improve motor function, motor fluctuations, health-related quality of life, and to reduce medication usage and drug-induced dyskinesia in patients with severe PD refractory to medical therapy. Little however, has been described on the impact of STN-DBS on the survival of these patients. We aim in this study to examine the impact of STN-DBS on the survival of patients with severe PD.

METHODS

Patients who were eligible for STN-DBS were given the choice of undergoing surgery or continuing on medical treatment. Those who exercised patient choice and preferred to continue with medical treatment formed a control population. All eligible patients seen in a 10-year period are included in this study. Our primary outcome measure is a difference in mortality between the two groups with a secondary measure of admission rates to residential (nursing home) care.

RESULTS

106 patients underwent STN-DBS, and 41 patients exercised patient choice and declined the procedure. The two groups were matched for age, gender, ethnicity, duration of disease, rates of pre-existing depression and Levodopa equivalent doses of anti-Parkinson's medications taken. Patients undergoing STN-DBS had significantly longer survival and were significantly less likely to be admitted to a residential care home than those managed purely medically. The statistical significance of these findings persisted after adjusting for potential confounding factors (survival: p=0.002, HR 0.29 (0.13 to 0.64) (residential care home admission: OR: 0.1 (95% CI 0.0 to 0.3; p<0.001).

INTERPRETATION

We show for the first time that there is a survival advantage of DBS surgery in advanced PD. The effect of potential bias factors is examined. The survival advantage may arise for several postulated reasons, ranging from improvement in axial functions, such as swallowing, to some as yet unrecognised benefit of reduction in dopaminergic medication. These findings are of great interest to both patients with PD and the health professionals considering the treatment options for patients with severe PD.

Differences in survival between patients with dementia with Lewy bodies and patients with Alzheimer's disease--measured from a fixed cognitive level

INTRODUCTION

The aim of this study was to compare survival in patients with Alzheimer's disease (AD) and patients with dementia with Lewy bodies (DLB). Since anamnestic and retrospective information about disease duration are unreliable variables, we measured survival from a fixed cognitive level.

METHODS

Survival time was measured from the reported disease onset, from the time of diagnosis, from Mini-Mental State Examination (MMSE) 20 ± 1, and from MMSE 17 ± 1.

RESULTS

Survival time was significantly shorter in the DLB group compared to the AD group both from the time of diagnosis and from the cognitive levels of 20 and 17 on the MMSE. There was no difference in survival when measured from the reported disease onset.

DISCUSSION

Our findings indicate that DLB patients have a more malignant clinical course. Our method of investigating survival in a cognitively homogenous population may gain scientific power. Reliable methods to predict survival and the clinical course are of great value for patients, caregivers, doctors, and society.

Estrogen actions in the brain and the basis for differential action in men and women: a case for sex-specific medicines

The classic view of estrogen actions in the brain was confined to regulation of ovulation and reproductive behavior in the female of all mammalian species studied, including humans. Burgeoning evidence now documents profound effects of estrogens on learning, memory, and mood as well as neurodevelopmental and neurodegenerative processes. Most data derive from studies in females, but there is mounting recognition that estrogens play important roles in the male brain, where they can be generated from circulating testosterone by local aromatase enzymes or synthesized de novo by neurons and glia. Estrogen-based therapy therefore holds considerable promise for brain disorders that affect both men and women. However, as investigations are beginning to consider the role of estrogens in the male brain more carefully, it emerges that they have different, even opposite, effects as well as similar effects in male and female brains. This review focuses on these differences, including sex dimorphisms in the ability of estradiol to influence synaptic plasticity, neurotransmission, neurodegeneration, and cognition, which, we argue, are due in a large part to sex differences in the organization of the underlying circuitry. There are notable sex differences in the incidence and manifestations of virtually all central nervous system disorders, including neurodegenerative disease (Parkinson's and Alzheimer's), drug abuse, anxiety, and depression. Understanding the cellular and molecular basis of sex differences in brain physiology and responses to estrogen and estrogen mimics is, therefore, vitally important for understanding the nature and origins of sex-specific pathological conditions and for designing novel hormone-based therapeutic agents that will have optimal effectiveness in men or women.

Physical assessment as a predictor of mortality in people with Parkinson's disease: a study over 7 years

The primary aim of this study was to ascertain whether a battery of physical function measures in a Parkinson's disease (PD) patient cohort predicted mortality status at 7-year follow-up. Secondary aims were establishing which specific tests were the most useful, and whether PD phenotype was a predictor. A retrospective correlation design was used in this study. A cohort of 109 PD patients underwent baseline physiotherapy assessment of gait, balance, posture, muscle strength, and ability to change postural set. We compared mortality status at 7-year follow-up and baseline physical assessment tests. Tinetti gait and balance scores, UPDRS score, 10-m walk test (time, velocity, and number of strides), posture in standing, lying to sitting, sitting to standing, getting up from floor assessments, and time to ascend and descend four steps were found to be statistically significant physical predictors of mortality at 7-year follow-up. In addition, age, sex, and mini-mental state examination were significant nonphysical predictors of mortality. Using Cox regression, a survival model was constructed with age, sex, and Tinetti gait score as independent predictors of mortality. The results of this study suggest that there is a link between reduced physical function and an increased mortality risk in PD populations.

Independent influences of sex steroids of systemic and central origin in a rat model of Parkinson's disease: A contribution to sex-specific neuroprotection by estrogens

This review considers evidence which reveals considerable complexity and sex differences in the response of the nigrostriatal dopaminergic (NSDA) system to hormonal influences. This pathway degenerates in Parkinson's disease (PD) and sex hormones contribute to sex differences in PD, where men fare worse than women. Here we discuss evidence from animal studies which allows us to hypothesize that, contrary to expectations, the acclaimed neuroprotective property of physiological concentrations of estradiol arises not by promoting NSDA neuron survival, but by targeting powerful adaptive responses in the surviving neurons, which restore striatal DA functionality until over 60% of neurons are lost. Estrogen generated locally in the NSDA region appears to promote these adaptive mechanisms in females and males to preserve striatal DA levels in the partially injured NSDA pathway. However, responses to systemic steroids differ between the sexes. In females there is general agreement that gonadal steroids and exogenous estradiol promote striatal adaptation in the partially injured NSDA pathway to protect against striatal DA loss. In contrast, the balance of evidence suggests that in males gonadal factors and exogenous estradiol have negligible or even harmful effects. Sex differences in the organization of NSDA-related circuitry may well account for these differences. Compensatory mechanisms and sexually dimorphic hard-wiring are therefore likely to represent important biological substrates for sex dimorphisms. As these processes may be targeted differentially by systemic steroids in males and females, further understanding of the underlying processes would provide valuable insights into the potential for hormone-based therapies in PD, which would need to be sex-specific. Alternatively, evidence that estrogen generated locally is protective in the injured male NSDA pathway indicates the great therapeutic potential of harnessing central steroid synthesis to ameliorate neurodegenerative disorders. A clearer understanding of the relative contributions and inter-relationships of central and systemic steroids within the NSDA system is an important goal for future studies.

Gender differences on MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) neurotoxicity in C57BL/6 mice

The aim of this study was to investigate the impact of gender difference in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated animal model of Parkinson's disease (PD). In the present study, we investigated the time-dependent alterations of dopamine and its metabolites, striatal tyrosine hydroxylase (TH) protein, dopamine transporter (DAT) protein, glial fibrillary acidic protein (GFAP) protein and midbrain TH protein and motor function in male and female mice 5h and 1, 3 and 7 days after four administrations of MPTP (20mg/kg) at 2-h intervals. The present study showed that the decrease of dopamine, DOPAC (3,4-dihydroxyphenylacetic acid) and HVA (homovanillic acid) content in female mice was more pronounced than that in male animals 1, 3 and 7 days after MPTP treatment. Our Western blot analysis study also demonstrated that the decrease of both striatal and midbrain TH protein levels in female mice was more pronounced than that in male animals from 1 to 7 days after MPTP treatment. As compared to male mice, in contrast, the increase of striatal GFAP protein levels in female mice was observed from 5h to 7 days after MPTP treatment. Furthermore, the present study showed that motor deficits were found in both male and female mice 1 and 7 days after MPTP treatment. In the present study, moreover, the decrease of striatal DAT protein levels in female mice was more pronounced than that in male animals 1, 3 and 7 days after MPTP treatment. These results demonstrate that our administrations of MPTP at 2-h intervals can cause more severe damage in female mice as compared with male animals. The gender difference may be due to the decrease of DAT expression caused by MPTP. Thus our findings provide further valuable information for the pathogenesis of PD.

Ginsenoside Rg1 protects dopaminergic neurons in a rat model of Parkinson's disease through the IGF-I receptor signalling pathway

BACKGROUND AND PURPOSE

We have shown that ginsenoside Rg1 is a novel class of potent phytoestrogen and activates insulin-like growth factor-I receptor (IGF-IR) signalling pathway in human breast cancer MCF-7 cells. The present study tested the hypothesis that the neuroprotective actions of Rg1 involved activation of the IGF-IR signalling pathway in a rat model of Parkinson's disease, induced by 6-hydroxydopamine (6-OHDA).

EXPERIMENTAL APPROACH

Ovariectomized rats were infused unilaterally with 6-OHDA into the medial forebrain bundle to lesion the nigrostriatal dopamine pathway and treated with Rg1 (1.5 h after 6-OHDA injections) in the absence or presence of the IGF-IR antagonist JB-1 (1 h before Rg1 injections). The rotational behaviour induced by apomorphine and the dopamine content in the striatum were studied. Protein and gene expression of tyrosine hydroxylase, dopamine transporter and Bcl-2 in the substantia nigra were also determined.

KEY RESULTS

Rg1 treatment ameliorated the rotational behaviour induced by apomorphine in our model of nigrostriatal injury. This effect was partly blocked by JB-1. 6-OHDA significantly decreased the dopamine content of the striatum and treatment with Rg1 reversed this decrease. Treatment with Rg1 of 6-OHDA-lesioned rats reduced neurotoxicity, as measured by tyrosine hydroxylase, dopamine transporter and Bcl-2 protein and gene level in the substantia nigra. These effects were abolished by JB-1.

CONCLUSIONS AND IMPLICATIONS

These data provide the first evidence that Rg1 has neuroprotective effects on dopaminergic neurons in the 6-OHDA model of nigrostriatal injury and its actions might involve activation of the IGF-IR signalling pathway.

Effects of estrogens on striatal damage after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in male and female mice

Emerging evidence shows a beneficial effect of estrogens for Parkinson's disease, yet the exact potency of these compounds implicated remain obscured. In this study, we investigated the neuroprotective effect of 17beta-estradiol and estrone against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced striatal toxicity in mice. The neuroprotective effects of both compounds were evaluated by HPLC and Western blot analyses 5 days after the last of 4 consecutive injections of MPTP at 1-h intervals to mice. Subacute treatment (10 days) with estrone or 17beta-estradiol at low doses (0.05 and 0.2mg/kg) showed no significant changes against MPTP-induced damage of striatal dopamine terminals in mice. Furthermore, acute treatment with estrone at high doses (0.5 and 2.0mg/kg) showed no significant alterations against MPTP-induced damage of striatal dopamine terminals in mice. In contrast, acute treatment with 17beta-estradiol at high doses exhibited a neuroprotective effect against the damage of striatal dopamine terminals in both male and female mice after MPTP treatments. The results demonstrate that estrogen therapy with high doses may have a neuroprotective effect on the damage of striatal dopamine terminals in the MPTP-induced mice. These findings may lead to be development of estrogen therapy for the prevention and treatment of Parkinson's disease.

Estrogen anti-inflammatory activity in brain: a therapeutic opportunity for menopause and neurodegenerative diseases

Recent studies highlight the prominent role played by estrogens in protecting the central nervous system (CNS) against the noxious consequences of a chronic inflammatory reaction. The neurodegenerative process of several CNS diseases, including Multiple Sclerosis, Alzheimer's and Parkinson's Diseases, is associated with the activation of microglia cells, which drive the resident inflammatory response. Chronically stimulated during neurodegeneration, microglia cells are thought to provide detrimental effects on surrounding neurons. The inhibitory activity of estrogens on neuroinflammation and specifically on microglia might thus be considered as a beneficial therapeutic opportunity for delaying the onset or progression of neurodegenerative diseases; in addition, understanding the peculiar activity of this female hormone on inflammatory signalling pathways will possibly lead to the development of selected anti-inflammatory molecules. This review summarises the evidence for the involvement of microglia in neuroinflammation and the anti-inflammatory activity played by estrogens specifically in microglia.

Prognostic factors for the progression of Parkinson's disease: a systematic review

The purpose of this systematic review is to summarize studies that describe the course of Parkinson's disease (PD) and to identify factors that predict change in motor impairment, disability, and quality of life. A literature search was conducted in MEDLINE, EMBASE, CINAHL, and Web of Science limited to the English, French, German, Spanish, and Dutch language. Reports were selected if the study involved subjects with PD, the outcome measures described impairment, disability, or quality of life and follow-up was at least 6 months. All included studies were scored for methodological quality. Data were extracted and summarized in a best evidence synthesis. We screened 1,535 titles and abstracts, of which 27 fulfilled our inclusion criteria. A meta-analysis to quantitatively aggregate progression scores of motor impairment and disability was not possible because of the wide variety of outcome measures used and the heterogeneous study populations. Limited evidence is found for lower UPDRS-ME at baseline, dementia and SE < 70% as prognostic factors for future motor impairment. There is strong evidence for higher age at onset and higher PIGD-score; and limited evidence for higher bradykinesia-score, non-tremor dominant subtype, symmetrical disease at baseline, and depression as prognostic factors for progression of disability. Prognostic factors were identified for impairment and disability. The literature on prognosis in PD is not fulfilling the high methodological standards applied nowadays. There is a need for prospective cohorts of PD patients assembled at a common early point in the disease with long time follow-up.

Loss of aromatase cytochrome P450 function as a risk factor for Parkinson's disease?

The final step in the physiological synthesis of 17beta estradiol (E(2)) is aromatization of precursor testosterone by a CYP19 gene product, cytochrome P450 estrogen aromatase in the C19 steroid metabolic pathway. Within the central nervous system (CNS) the presence, distribution, and activity of aromatase have been well characterized. Developmental stage and injury are known modulators of brain enzyme activity, where both neurons and glial cells reportedly have the capability to synthesize this key estrogenic enzyme. The gonadal steroid E(2) is a critical survival, neurotrophic and neuroprotective factor for dopaminergic neurons of the substantia nigra pars compacta (SNpc), the cells that degenerate in Parkinson's disease (PD). In previous studies we underlined a crucial role for the estrogenic status at the time of injury in dictating vulnerability to the parkinsonian neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Our ongoing studies address the contribution of brain aromatase and extragonadal E(2) as vulnerability factors for PD pathology in female brain, by exposing aromatase knockout (ArKO, -/-) female mice which are unable to synthesize estrogens to MPTP. Our initial results indicate that aromatase deficiency from early embryonic life significantly impairs the functional integrity of SNpc tyrosine hydroxylase-positive neurons and dopamine transporter innervation of the caudate-putamen in adulthood. In addition, ArKO females exhibited a far greater vulnerability to MPTP-induced nigrostriatal damage as compared to their Wt type gonadally intact and gonadectomized counterparts. Characterization of this novel implication of P450 aromatase as determining factor for PD vulnerability may unravel new avenues for the understanding and development of novel therapeutic approaches for Parkinson's disease.

Neuroprotective effects of genistein on dopaminergic neurons in the mice model of Parkinson's disease

Emerging evidence suggests beneficial effects of estrogen and estrogen-like chemicals on neurodegenerative diseases, especially Parkinson's disease (PD). Genistein, an isoflavone naturally found in soy products, displays estrogenic properties. The present study aims to investigate the neuroprotective effects of genistein on dopaminergic neurons in ovariectomized (OVX), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model mice. MPTP significantly decreased the levels of dopamine (DA) and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum, which could be restored by genistein or estrogen pretreatment. MPTP-challenge with genistein or estrogen pretreatment demonstrated reduced neurotoxicity, with tyrosine hydroxylase-immunoreactive (TH-IR) neurons in the substantia nigra pars compacta (SNpc) affected to a significantly lesser extent as compared to the MPTP treated control. The reverse transcription-PCR results also confirmed that the MPTP-induced downregulation of TH, dopamine transporter (DAT) and Bcl-2 mRNA expression in the midbrain could be restored by genistein or estrogen pretreatment. These findings provide the first evidence that genistein has neuroprotective effects on dopaminergic neurons in the MPTP-induced PD mice and this effect may be attributed to enhancing Bcl-2 gene expression.

17β-Estradiol reduces nitrotyrosine immunoreactivity and increases SOD1 and SOD2 immunoreactivity in nigral neurons in male mice following MPTP insult

Emerging evidence suggests the beneficial effects of estrogen on Parkinson's disease (PD), yet the mechanisms of action implicated remain elusive. While experimental evidence suggests that estrogen possesses potent antioxidative properties, it is still unknown whether the hormone exhibits a neuroprotection in a PD animal model through its antioxidant activities. This study therefore investigated the effects of 17beta-estradiol (E2) on the immunoreactivity of nigral neurons and glia for nitrotyrosine (NT, a stable marker for oxidative stress), Cu/Zn superoxide dismutase (SOD1) and Mn superoxide dismutase (SOD2) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model. Adult male mice were treated with E2 or vehicle for 11 days during which they were injected with MPTP or saline on the sixth day. The brains were collected on day 11 and quantitative immunohistochemistry was used to assess the number of NT-, SOD1- and SOD2-immunoreactive (IR) cells in the substantia nigra pars compacta (SNpc). In saline-treated group, E2 decreased NT-IR neuronal number and raised SOD1 and SOD2 expression in neurons and glia in the SNpc. MPTP induced a significant increase in the number of NT- and SOD2-IR neurons, but decreased the number of SOD1-IR neurons. MPTP also triggered a significant increase of SOD2- and SOD1-IR glial number. E2 pretreatment in MPTP mice reduced the number of NT-IR neurons, increased the number of SOD1- and SOD2-IR neurons, but did not alter the MPTP effect on glia immunoreactive to either SOD. Stimulation of SOD1 and SOD2 expression in nigral neurons suggests that E2 provides neuroprotection against MPTP-induced oxidative stress, partly through its ability to act as an antioxidant.

Striatal susceptibility to a dopaminergic neurotoxin is independent of sex hormone effects on cell survival and DAT expression but is exacerbated by central aromatase inhibition

The aim of this study was to investigate further the hormone-dependent processes underlying sex differences in neurotoxic responses within the rat nigrostriatal dopaminergic (NSDA) pathway after partial lesioning with 6-OHDA, a state thought to mimic the early stages of Parkinson's disease where, in humans and animal models alike, males appear to be more susceptible. Contrary to our hypotheses, hormone manipulations (gonadectomy +/- oestrogen or androgen treatment) failed to alter survival of tyrosine hydroxylase immunoreactive cells in the substantia nigra pars compacta (SNc) after lesioning; this indicates that, unlike inherent sex differences in toxin-induced striatal dopamine depletion, sex differences in cell loss were not hormonally generated, and that hormone-dependent changes in dopamine depletion can occur independently of cell survival. In addition, hormonally induced changes in striatal expression of the dopamine transporter (DAT), an important factor for 6-OHDA toxicity, did not correlate with hormonal influences on striatal dopamine loss and, in males, central inhibition of aromatase prior to 6-OHDA infusion exacerbated striatal dopamine loss with no effect on SNc tyrosine hydroxylase-immunoreactive survival, suggesting locally generated oestrogen is neuroprotective. These results support the novel view that sex steroid hormones produced peripherally and centrally play a significant, sex-specific role within the sexually dimorphic NSDA pathway to modulate plastic, compensatory responses aimed at restoring striatal dopamine functionality, without affecting cell loss.

Gender disparities in Parkinson's disease

Parkinson's disease is a chronic neurodegenerative disorder of unknown etiology. There are sparse data on gender differences in this disorder, but it is clear that there are gender discrepancies in incidence, symptoms, medication effects and treatments. There also appear to be lifecycle fluctuations in the disease course of female Parkinson's disease patients. The effect of estrogen in this disorder is multifold and its role in the development and treatment of PD will be discussed.

Increased lifespan in transgenic Caenorhabditis elegans overexpressing human alpha-synuclein

alpha-Synuclein is a short 14-kDa protein found in pathological lesions of age-related neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and multiple system atrophy. Its overexpression in transgenic mice, rats, Drosophila melanogaster, and Caenorhabditis elegans recapitulates many of the pathologic features observed in human Parkinson's disease including loss of dopaminergic neurons and motor deficits. Integrated transgenic C. elegans lines were generated that overexpress either human wildtype (WT) or mutant (A53T) forms. These transgenic lines demonstrated approximately 25% increase in lifespan (p<0.0001) compared to controls. When the transgenes were crossed into long-lived daf-2 (m577) or daf-2 (e1370) genetic backgrounds, the lifespan increase was also approximately 25% in comparison to the corresponding daf-2 strains (p<0.05). Pharyngeal pumping and egg laying were significantly decreased in the overexpressing transgenic lines, and lifespan increases were attenuated when lines were grown on thick bacterial lawns, suggesting that caloric restriction may explain some of the effects on lifespan. These studies provide initial evidence for a beneficial role of human alpha-synuclein in influencing lifespan.

Survival of Parkinson's disease patients in a large prospective cohort of male health professionals

Parkinson's disease (PD) patients have higher mortality than individuals without PD. However, most of the previous studies were based on prevalent cases and few examined the potential effects of duration and smoking on the survival of PD patients. We compared the survival experience of 288 men with incident PD diagnosed between 1986 and 2000 with that of 51,012 men free of PD in the Health Professionals Follow-up Study. As of January 2002, 92 deaths occurred among PD cases and 8,485 among men without PD. After controlling for age, men with PD had 60% higher mortality than those without PD (95% CI: 1.3-2.0). PD mortality was strongly related to disease duration: compared with men without PD, the age-adjusted relative risk for PD patients was 1.1 during the first 5 years from diagnosis, 2.3 from 5 to 10 years, and 3.5 after 10 years (P < 0.0001 for trend). As expected, cigarette smoking was strongly and positively associated with total mortality among men free of PD (comparing >30 pack-years vs. never smokers, relative risk, 2.0; P < 0.0001 for trend), but this association was not observed among PD patients (RR: 1.0; P = 0.95 for trend). This study confirms that PD patients have a higher mortality than individuals without PD and that the excess mortality increases with disease duration. However, smoking seems to impose little additional risk among PD patients in this large cohort of health professionals.

Estrogen down-regulates glial activation in male mice following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine intoxication

Emerging evidence suggests beneficial effect of estrogen for Parkinson's disease (PD), yet the exact mechanisms implicated remain obscured. Activated glia observed in MPTP mouse model and in PD may participate in the cascade of deleterious events that ultimately leads to dopaminergic nigral neuronal death. In vitro studies demonstrate that estrogen can modify the microglial and astroglial expression of inflammatory mediator, such as cytokines and chemokines implicated in neuroinflammation and neurodegeneration. To determine whether estrogen-elicited neuroprotection in PD is mediated through glia, adult male C57Bl/6 mice were treated with 17beta-estradiol (E2) for a total of 11 days. Following 5 days of pretreatment with E2, they were injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the sixth day. The brains were collected on day 11. Immunohistochemistry and quantitative study were used to assess the number of tyrosine hydroxylase-immunoreactive (TH-IR) neurons in the substantia nigra pars compacta (SNpc) and that of activated astrocytes and activated microglia in the SNpc and the striatum. Pretreatment with E2 decreased the loss of TH-IR nigral neurons and diminished the deficit of TH-IR striatal fibers triggered by MPTP. The neuroprotective effect of E2 was coincident with an attenuation of a glial response within the nigra and the striatum. These findings suggest that the neuroprotective effects of E2 evidenced in MPTP mouse model might mediate through an inhibition of reactive glia. However, direct neuroprotective effects of E2 upon TH-IR neurons cannot be excluded.

Prognosis of Parkinson's disease: Time to stage III, IV, V, and to motor fluctuations

We report a long-term outcome on a large cohort of Japanese patients with Parkinson's disease (PD). A total of 1,768 (793 men, 975 women) consecutive patients visited our clinic from 1 January 1989 to 31 December 2002. Among them, 1,183 patients (531 men, 652 women) came to our clinic within 5 years from the onset of disease and at the Hoehn & Yahr Stage III or less at the first visit. Long-term outcome was evaluated in this subcohort of the patients. We examined the duration to reach Stage III, IV, and V, and the duration to develop wearing off and dyskinesia. Time to reach Stage III was slightly but significantly shorter in women, in that 23.8% of men and 35.3% of women reached Stage III by the end of the 5th year; 49.7% of men and 63.3% of women reached Stage III by the end of the 10th year, and 88.9% of men and 79.9% of women by the end of the 15th year (P < 0.001). Also, durations to develop wearing off and dyskinesia were shorter in women compared to men. These data suggest that the disease progression may be slightly faster for women. Young-onset patients showed significantly longer duration to reach Stage III, IV, and V but shorter duration to develop wearing off and dyskinesia. Not many studies are available in the literature on the long-term outcome of PD, and our data would be useful as a reference.

Gender and the Parkinson's disease phenotype

OBJECTIVES

To determine whether there are gender differences in the Parkinson's disease (PD) phenotype using a large clinic-based cohort.

METHODS

We examined gender differences in demographic, historical and clinical characteristics in a consecutive clinical series of 1,264 individuals diagnosed with PD.

RESULTS

The majority of individuals in the sample were male (67 %). Comparative analyses showed males and females were not significantly different on most demographic and historical characteristics. For both genders, the mean age and the mean age at symptomatic onset were about 70 and 63 years, respectively and, thus, disease duration was not significantly different between genders. The proportion of individuals with a positive family history of PD (15 %) was similar for both genders. A positive history of depression was significantly higher in females (35 % vs. 24 %). The UPDRS instability score was significantly worse among females, whereas the rigidity score was significantly worse for males. Females showed significantly worse ADL capacity and a more advanced H&Y stage. The proportion of individuals receiving antiparkinsonian medication (about 66 %) and time between the last dose and the clinical evaluation (about 4 hours) was similar for both genders. There was a trend for lower daily levodopa equivalence dosage and more severe dyskinesia score among females but these differences did not reach statistical significance after Bonferroni correction.

CONCLUSIONS

The majority of comparisons tended to highlight the commonalities in the PD phenotype between genders, particularly in reference to historical and early disease stage characteristics. However, gender may be an important factor related to the expression of PD features during the symptomatic disease course.

Oestrogens prevent loss of dopamine transporter (DAT) and vesicular monoamine transporter (VMAT2) in substantia nigra of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice

Previous results from our laboratory have shown that 17beta-oestradiol prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) striatal dopamine depletion. 17beta-oestradiol, oestriol and oestrone are the naturally occurring oestogens in humans. Using various dopamine markers, the present study investigated whether oestrone and oestriol such as 17beta-oestradiol have neuroprotective activity in MPTP-treated mice. Male mice were treated with 17beta-oestradiol, oestriol or oestrone for 5 days before and after MPTP administration, and were compared with nonlesioned mice receiving the same treatment. Striatal concentrations of dopamine and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were assayed by high-performance liquid chromatography. Dopamine transporter (DAT) and vesicular monoamine transporter (VMAT2) specific binding were measured by autoradiography. DAT, VMAT2 and tyrosine hydroxylase mRNA levels were measured by in situ hybridisation. MPTP induced a loss of DAT and VMAT2 specific binding in the striatum and substantia nigra, as well as a decrease of VMAT2 mRNA in the substantia nigra. 17beta-oestradiol treatment prevented the loss of these dopaminergic markers, as well as striatal concentrations of dopamine, DOPAC and HVA. Mice receiving oestriol and oestrone showed catecholamine concentrations comparable to MPTP mice. Oestriol treatment had no effect on dopaminergic markers in MPTP mice whereas oestrone prevented striatal DAT loss and the decrease of VMAT2 mRNA in the substantia nigra. In nonlesioned mice, 17beta-oestradiol, oestriol or oestrone had no effect on all the dopaminergic markers investigated. In conclusion, a weak or a lack of effect of oestriol and oestrone was observed compared to 17beta-oestradiol in MPTP mice and none of these steroids had an effect in nonlesioned mice. A DAT and VMAT2 specific binding decrease after MPTP in the striatum and substantia nigra, as well as a decrease of substantia nigra VMAT2 mRNA, was observed and could be prevented by oestradiol.