How common are complications of Parkinson's disease?

Background Parkinson's disease (PD) can be associated with a wide range of complications of advancing disease and treatment. However, it is unclear how often these occur in the overall population of patients with PD. Objective To assess the prevalence of disease and treatment complications and their clinical correlates in a community-based sample of 124 patients with PD. Results Average current age was 72 (SD 10.9) and mean disease duration 6 (SD 4.3) years. Falls with postural instability and other axial features were among the most common complications of advancing disease in this population (64 %). Motor fluctuations and dyskinesias affected approximately 30 and 20 % of the overall sample respectively, and changes in mental state such as dementia, depression and hallucinations each affected approximately one fifth of patients. Symptoms of autonomic nervous system dysfunction occurred in the great majority of patients, but were not associated with greater disease severity, disease duration or overall disability. Conclusion In contrast to clinic-based samples, the most frequently occurring complications of PD in this community-based sample were axial features such as postural instability with falls. These factors should be more taken into account in the allocation of health care resources and the treatment of symptoms of patients with PD in the community. Received: 31 January 2001, Received in revised form: 8 August 2001, Accepted: 21 August 2001     

Differential progression of motor impairment in levodopa-treated Parkinson's disease.

OBJECTIVE: To monitor comparative progression of clinical impairment over 4 years in patients with Parkinson's disease (PD) who present on levodopa at two different levels of Hoehn and Yahr (HY) stages, II and III. BACKGROUND: The rate of clinical impairment progression in patients with PD being treated with levodopa has not been studied in detail using current, standardized assessment tools. Sample size estimates for all levodopa adjunctive treatment studies and proper definition of study groups require a solid estimate of longitudinal motor impairment progression. DESIGN/METHODS: From our computer database, we identified two groups of patients with PD being treated with levodopa based on their initial HY stage at presentation to our center (II or III). Fifty randomly selected subjects in each stage were monitored in the ON state with annual Unified Parkinson's Disease Rating Scale (UPDRS) motor scores, dyskinesia ratings, and antiparkinsonian medication doses using a repeated measures analysis of variance. RESULTS: The stage II and stage III subjects had similar disease duration. In stage II subjects, parkinsonian impairment was maintained without progression over 4 years, but in association with significantly higher dyskinesia scores and dopaminergic medication doses. In stage III subjects, UPDRS motor scores deteriorated despite more medication and increased dyskinesias. Of the established six factors comprising the UPDRS motor scale, bradykinesia accounted for the increased impairment. Initial UPDRS motor score and disease duration did not influence progression of motor impairment. CONCLUSION: In subjects with similar disease duration, progression of PD motor impairment differs significantly between stage II and stage III subjects over 4 years. Whereas in stage II subjects, parkinsonian impairment can be stabilized at the expense of increased dyskinesia and dopaminergic drugs, once subjects reach stage III, motor impairment progresses. Power estimates and sample size calculations for these groups of patients should be calculated separately.     

Employment, medical absenteeism, and disability perception in Parkinson's disease: A pilot double-blind, randomized, placebo-controlled study of entacapone adjunctive therapy.

The objective of this study was to test the impact of entacapone (ENT) addition to levodopa with a decarboxylase inhibitor (LD) in full-time-employed patients with Parkinson's disease (PD), focusing on retirement rates, medical absenteeism, self-perception of disability, as well as motor assessments of parkinsonism, motor fluctuations, and dyskinesias. Thirty full-time-employed PD patients (disease onset before age 60 years) and on optimized monotherapy with LD exhibiting minor motor fluctuations or dyskinesias were entered into a 2-year randomized double-blind placebo-controlled study of ENT adjunctive therapy. The outcome measures were the number of full-time-employed patients at study end, cumulative days of medical absenteeism, patient-completed disability assessments, diary records, and the Unified Parkinson's Disease Rating Scale-based measures of motor fluctuations and dyskinesias. LD + ENT treatment was associated with a lower retirement rate (2 [17%] of 12 vs. 6 [50%] of 12; P = 0.12), lower absenteeism rate (21.5 vs. 43.5 days; P < 0.0001), improved self-perception of disability progression over 2 years (change score 1.0 vs. 4.5; P < 0.0001), and lower scores for both motor fluctuations and dyskinesia assessments compared to LD monotherapy. In this pilot study, LD with ENT adjunctive therapy positively influenced employment rate over 2 years; this effect was associated with reduced motor complications and patient perceptions of stabilized disability.     

Clinical problems in non-fluctuating patients with Parkinson's disease: a community-based study.

OBJECTIVE: To investigate the frequency of nonfluctuators in a community-based prevalence study of Parkinson's disease (PD) and to describe disability, non-motor problems, and health-related quality of life in patients with PD with and without motor fluctuations, and compare the findings to those of two control groups. METHODS: The study involved 245 patients with PD who were participating in a prevalence study and two control groups (100 healthy elderly individuals and 100 patients with diabetes mellitus [DM]). Data were obtained through neurologic examination and a semistructured interview, and by the use of several questionnaires. RESULTS: In this group of unselected patients with PD, 78% did not experience motor fluctuations. Mean duration of treatment with levodopa was 6.3 years. Patients with motor fluctuations had a lower age at onset of disease, longer duration of disease, and a higher daily levodopa dose than patients without fluctuations. Among the non-fluctuating patients, we found more dementia and a higher age at prevalence day. Disability (assessed by the Unified Parkinson's Disease Rating Scale subscales for activities of daily living and motor function and the Hoehn and Yahr stage) was similar in fluctuators and nonfluctuators. Depression, sleep disturbances, and fatigue were equally frequent in both patient groups. The occurrence of these difficulties was clearly more frequent among non-fluctuating patients with PD than among the control subjects. CONCLUSION: Most patients in the general population who have PD do not experience dose-dependent motor fluctuations. Severity of motor disability and neuropsychiatric manifestations are as important in non-fluctuators as in fluctuators. Patients without motor fluctuations have more depression, sleep disturbances, fatigue, and a poorer health-related quality of life than patients with DM and healthy elderly individuals. This also underlines the importance of developing better management and treatment strategies for this group of patients with PD.     

Factors affecting the quality of life of patients with idiopathic Parkinson's disease--a cross-sectional study in an outpatient clinic attendees

PURPOSE: To determine the factors associated with poor quality of life (QoL) in patients with idiopathic Parkinson's disease (PD) in a clinic-based sample. SCOPE: One hundred patients were included in this study. To assess the quality of life the Parkinson's Disease Questionnaire (PDQ-39) was used. A structured questionnaire interview and a complete neurological examination, including the Hoehn and Yahr scale (H-Y), the Schwab and England disability scale, II, III, IV parts of the unified Parkinson's disease rating scale (UPDRS part II, III, IV), Montgomery-Asberg depression rating scale (MADRS) and the Mini-Mental state examination (MMSE) were performed. RESULTS AND CONCLUSIONS: The most important predictive factor was MADRS score, followed by clinical fluctuations as measured by UPDRS part IVB and the H-Y stage of disease, which account for 79% of the variance of QoL scores. Therefore, recognition of depression should become an important part of treatment of PD.     

Clinical measures of progression in Parkinson's disease

Despite all recent advances in symptomatic therapy Parkinson's disease (PD) continues to be a relentlessly progressive neurodegenerative disorder. Therefore therapies that will slow or hold disease progression are a major medical unmet need in PD. Clinical measures of disease progression that have been used in disease modification trials so far have focused on indices of progression of cardinal motor features like bradykinesia, rigidity, and tremor as captured by the UPDRS and the emerging need for effective dopaminergic symptomatic therapy. Progression of global disability in PD, however, is driven by additional factors beyond progressive nigrostriatal denervation leading to increasing severity of cardinal motor features. Progressive pathology in extranigral sites in the brain or peripheral autonomic nervous system contribute to poorly levodopa responsive motor symptoms like postural instability, freezing and falls or nonmotor symptoms. In addition treatment‐induced motor complications also impact on PD disability. Although it is widely accepted that clinical progression of PD is multidimensional and in addition includes effects of aging, there is no consensus how to best implement more clinically meaningful endpoints for disease progression trials that would reflect these complex interactions impacting on the evolution of global disability in PD. There is an urgent need for biomarkers for disease progression that would faithfully reflect advancing neurodegeneration and resulted clinical disability in PD and that could be used in shorter term clinical trials testing putative disease modifying agents. © 2009 Movement Disorder Society     

Variable expression of Parkinson's disease: a base-line analysis of the DATATOP cohort. The Parkinson Study Group

The DATATOP database, which includes clinical information on 800 patients with early untreated Parkinson's disease (PD), is well suited to explore clinical heterogeneity in PD. Patients with early-onset PD (less than or equal to 40 years, N = 33) reached the same level of disability as the late-onset PD (greater than or equal to 70 years, N = 85) group at a significantly slower rate (2.9 vs. 1.7 years). Early-onset PD patients functioned cognitively better than late-onset PD patients. Bradykinesia, and postural instability and gait difficulty (PIGD), were more common at onset in patients with a rapid rate of disease progression ("malignant PD"; duration of symptoms less than 1 year and Hoehn/Yahr stage of 2.5, N = 11) as compared with those with a relatively slow rate of progression ("benign PD"; duration of symptoms greater than 4 years, N = 65). Comparisons of tremor-dominant PD (mean tremor score/mean PIGD score less than or equal to 1.5, N = 441) with the PIGD-dominant type (mean tremor score/mean PIGD score greater than or equal to 1.0, N = 233) provided support for the existence of clinical subtypes. The PIGD group reported significantly greater subjective intellectual, motor, and occupational impairment than the tremor group. Stage II patients had higher depression scores than stage I patients. Among the patients participating in the DATATOP, older age at onset with bradykinesia, or with the PIGD form of PD, is associated with more functional disability than when the symptoms are dominated by tremor or begin at a younger age.     

Risk factors for hallucinations in Parkinson's disease: Results from a large prospective cohort study

The aim of this study was to identify risk factors for the development of hallucinations in patients with Parkinson's disease (PD). A broad range of motor and nonmotor features was assessed at baseline and during the following 5 years in 386 PD patients. Cross‐sectional analyses of baseline data and longitudinal analyses of follow‐up data were performed to identify risk factors for hallucinations in PD. Twenty‐one percent of the patients had hallucinations at baseline, whereas 46% of the patients without hallucinations at baseline developed this feature during follow‐up. Univariate survival analysis showed that older age, female sex, less education, higher age at onset, and more severe motor and cognitive impairment, depression, daytimes sleepiness, autonomic dysfunction, and motor fluctuations and dyskinesias, as well as higher daily levodopa dose, were associated with the risk of developing hallucinations. This largely corresponds with the features that were associated with the presence of hallucinations at baseline. In a stepwise regression model, older age at onset, female sex, excessive daytime sleepiness, autonomic dysfunction, and dyskinesias emerged as independent risk factors for developing hallucinations. Female sex, autonomic dysfunction, motor fluctuations, and dyskinesias have not been reported as risk factors in previous studies. These findings lend support to the notion that hallucinations in PD are caused by a combination of risk factors that are associated with (the interaction between) older age and more advanced disease. The identification of female sex as a risk factor for developing of hallucinations in PD is a new finding and should be verified in future studies. © 2013 Movement Disorder Society     

Late-stage Parkinson disease

The cardinal symptoms of Parkinson disease (PD) are asymmetrical bradykinesia, rigidity, resting tremor and postural instability. However, the presence and spectrum of, and disability caused by, nonmotor symptoms (NMS) are being increasingly recognized. NMS include dementia, psychosis, depression and apathy, and are a major source of disability in later stages of PD, in association with axial symptoms that are resistant to levodopa therapy. The model of clinical progression of PD should, therefore, incorporate NMS, instead of being restricted to motor signs and levodopa-induced motor complications. Patients with disabling motor complications are classified as having advanced PD, which has been thought to represent the ultimate stage of disease. However, deep brain stimulation to treat motor complications has dramatically changed this scenario, with implications for the definition of advanced-stage disease. As treatment improves and survival times increase, patients are increasingly progressing to a later phase of disease in which they are highly dependent on caregivers, and disability is dominated by motor symptoms and NMS that are resistant to levodopa. In this article, we review the changing landscape of the later stages of PD, and propose a definition of late-stage PD to designate patients who have progressed beyond the advanced stage.     

Entacapone in the treatment of Parkinson's disease

BACKGROUND: The development of fluctuations in motor response and involuntary movements commonly complicate the treatment of Parkinson's disease (PD). Catechol-O-methyltransferase (COMT) inhibitors delay the breakdown of levodopa, which leads to an increase in levodopa bioavailability and more stable concentrations of plasma levodopa. The addition of a COMT inhibitor therefore combines the rapid onset of levodopa with prolonged efficacy, and theoretically provides a more continuous stimulation of dopamine receptors with reduced risk of motor complications. Randomised, controlled trials have shown that in patients with PD who have motor fluctuations, the addition of the COMT-inhibitor entacapone results in an improvement in motor fluctuations, particularly of the "wearing-off" type, with about 1.0-1.7 h more on-time and less off-time per day, reduced required levodopa dose, modest improvement in motor and disability scores (mean total unified PD rating scale [UPDRS] scores of about 4.5), and in some but not all studies improvement of health-related quality of life [HRQOL] scores. RECENT DEVELOPMENTS: Patients with stable PD, without motor fluctuations, also have improved HRQOL scores on treatment with entacapone in addition to levodopa with a dopa-decarboxylase inhibitor. However, in a recent large multicentre study, UPDRS motor and disability scores were not improved despite significant improvements in HRQOL scores. The disparity between results on clinical rating scales and HRQOL scores suggests that these scales give different and potentially complementary information on health status changes in PD, and that entacapone provides benefit that may not be captured with standard clinical rating scales. Whether entacapone combined with levodopa can delay dyskinesia or motor fluctuations in patients with untreated PD is unknown; however, in animal studies, a decrease in motor complications has been reported in drug-naive animals given frequent doses of levodopa combined with entacapone. WHERE NEXT?: Clinical studies are underway to address the hypothesis that motor complications in PD can be delayed if entacapone is given from the start of treatment. Until the results of these trials are available, entacapone is indicated as a useful adjunct to levodopa in the symptomatic treatment of patients with PD with and without motor fluctuations. In addition, future trials should specifically assess the effect of entacapone on HRQOL in PD.     

Quality of life in early Parkinson's disease: impact of dyskinesias and motor fluctuations.

The impact of dyskinesias and motor fluctuations on quality of life (QOL) at various stages in the course of Parkinson's disease (PD) is not well understood. In 301 subjects with early PD enrolled in a clinical trial (CALM-PD), we quantified the impact of motor complications on QOL and investigated how this changes over time. We also compared QOL related to demographic and treatment characteristics. The presence of dyskinesias was associated with visual analogue scale (VAS) scores 3.0 of 100 points higher (better) than those without dyskinesias in years 1 to 2, even when adjusting for Unified Parkinson's Disease Rating Scale (UPDRS) motor scores. The positive association between dyskinesias and QOL scores was more marked in older patients. In years 3 to 4, dyskinesias no longer had a significant relationship with QOL. Younger subjects had higher VAS scores. Gender, motor fluctuations, and treatment regimen had no significant association with QOL, although a trend was found toward a small negative effect of motor fluctuations on QOL. We conclude that motor complications that occur within the first 4 years of treatment of PD do not have a significant negative effect on quality of life as measured by a visual analogue scale for most patients.     

Does clinical rapid eye movement behavior disorder predict worse outcomes in Parkinson’s disease?

Our purpose of this study was to investigate whether clinical rapid eye movement sleep behavior disorder (RBD) is indicative of more widespread degenerative changes in Parkinson’s disease (PD), using a longitudinal cohort. In 2005 and 2007, we prospectively collected clinical and treatment characteristics of 61 consecutive patients with PD. The presence of RBD was assessed by spouse interview. Sixty-four percent of patients had clinical RBD in 2005, versus 52% of patients in 2007. The yearly incidence rate of clinical RBD onset was 9%, while clinical RBD disappeared in 14% of patients per year. The motor disability scores (when treated) were worse in patients with than without clinical RBD in 2005, but not in 2007. There was no difference between groups for frequency of freezing, falls, and hallucinations, or for scores on the depression scale, sleepiness scale, mini-mental state examination and frontal assessment battery at the beginning versus the end of the study. Patients with clinical RBD were disabled earlier than patients without RBD, but there was no specific worsening in the RBD group with time, either for motor or non-motor symptoms. The fluctuation and disappearance of clinical RBD in some patients may be due to functional abnormalities rather than lesions.     

Depression in patients with Parkinson's disease

The aim of our study was to assess the frequency of depression in group of patients with Parkinson's disease (PD) who fulfilled the diagnostic criteria of PD, had normal CT scans and responded well to L-dopa treatment. The sample consisted of 73 consecutive patients (34 women and 39 men), mean age 65.7 (41-81) years, mean duration of disease 6.7 years. Besides neurological examination, in all the patients the degree of motor impairment was evaluated using the UPDRS, H-Y, and SE scales. Moreover, a sociodemographic questionnaire, psychological tests (MADRS, MMSE), and a quality of life scale (PDQ-39) were used. Depression (MADRS scores > 19) was found in 25 (34.2%) of the patients, with major depression (scores > 28) diagnosed in 7 patients (9.5%) and moderate depression (scores between 20 and 28)--in 18 cases (24.6%). In comparison to non-depressed patients, those with depression were older by 0.9 years on the average, their onset of the disease occurred later by 1.7 years, and their mean duration of the disease was longer by 2.6 years. These differences were not statistically significant. Dementia (MMSE scores < or = 23) did not differentiate between the two groups: it was found in 27 depressed patients (37.4%) and in 26 (35.6%) of those without depression. Patients in the depressed group suffered statistically more often from sleep disorders (19 vs. 14; p < 0.001). In this group motor impairment was significantly more marked, as measured by the UPDRS (32.2 vs. 46.8; p < 0.001) and H-Y (2.54 vs 2.98; p < 0.007), and their quality of life as measured by PDQ-39 questionnaire was significantly lower (36.4 vs. 82.24; p < 0.00002). Our data indicate the presence of depression in 34.2% of the sample, i.e. a somewhat lower prevalence rate than that reported in other studies. This may be due to the fact that only outpatient population was analysed, and outpatients are seldom categorized as degree 4 and 5 on the H-Y scale. Depression on PD patients was correlated with their more severe motor disability and considerably lower quality of life. This may suggest a relationship with progression of the disease and more pronounced changes in cerebral neurotransmitters (i.e. endogenous origin), or PD patient's response to their limited mobility and isolation in later stages of the disease (i.e. reactive origin). However, the two factors--endogenous and reactive--may be overlapping, since a majority of PD patients suffer from mild to moderate depression.     

The ups and downs of Parkinson disease: a prospective study of mood and anxiety fluctuations.

BACKGROUND: Parkinson disease (PD) patients with motor fluctuations experience mood fluctuations, but studies have been limited in number and methodology. OBJECTIVES: To better understand the phenomenology of mood, anxiety, and motor fluctuations in PD. METHOD: Eighty-seven PD patients and 19 spouse controls completed questionnaires, rating scales, and diaries using visual analogue scales (VAS) to rate mood, anxiety, and motor states. Average daily variance in VAS scores was determined, and PD patients whose average daily variance was larger than that for all of the control subjects were considered to have fluctuations. RESULTS: Twenty-nine percent of patients had fluctuations in anxiety, 24% motor, and 21% mood; 65% had no fluctuations. Seventy-five percent of patients with motor fluctuations had mood and/or anxiety fluctuations, but 5 subjects reported emotional fluctuations without motor fluctuations. The combination of mood and anxiety fluctuations was frequent, but anxiety and mood did not always appear to fluctuate together. Visual inspection of diaries revealed that not all patients exhibited a temporal relationship between emotional and motor fluctuations. Compared with nonfluctuators, those with mood or anxiety fluctuations were more likely to have higher scores on psychiatric rating scales, report histories of depression or anxiety, and use psychotropic medications. CONCLUSIONS: PD patients are heterogeneous with regard to the presence, range, and pattern of fluctuations. In general, patients with mood fluctuations also have anxiety fluctuations.     

The pattern of depressive symptoms varies with progression of Parkinson''s disease.

Whether or not depressive symptoms increase in severity with progression of Parkinson's disease (PD) remains uncertain. Unlike previous studies, we examined whether the severity of specific features of depression (mood, self reproach, vegetative, and somatic symptoms) differ with respect to the progression of PD. Results indicated that symptoms related to both mood and self-reproach were present in the early stages of PD but did not increase in severity with advancing disease. Somatic features of depression were evident early and increased with disease progression, and vegetative symptoms were seen only in the later stages of PD. The different patterns of these depressive features with progression of PD may account in part for the variations seen in previous studies.     

Motor response to levodopa in patients with parkinsonian motor fluctuations: a follow-up study over three years.

To clarify the way in which the clinical response to levodopa changes with the progression of Parkinson's disease, a longitudinal study was performed to quantify motor response characteristics to single doses of levodopa by mouth over three years in 23 patients with fluctuating motor function. A significant increase in motor disability in "on" (time of peak motor improvement) and "off" (before levodopa dose) phases occurred and "on" phase dyskinesia increased by 24%, though the amplitude of motor response was conserved. There was no evidence of progressive loss of response of certain motor deficits affecting axial muscles and gait. The mean duration of motor response decreased by 17%. Both shortening of response duration and increase in "off" phase disability contribute to the development of motor fluctuations. A short response time to the levodopa test dose was not an invariable finding in patients with severe fluctuations, whereas all had large response amplitudes and high "off" phase disability scores. Patients who have developed motor fluctuations may continue to respond to dopaminergic treatment until late in the disease course, despite the unstable nature of their responses.     

Magnetic Resonance Parkinsonism Index for evaluating disease progression rate in progressive supranuclear palsy: A longitudinal 2-year study

IntroductionWe investigated the disease progression rate in patients with progressive supranuclear palsy-Richardson syndrome (PSP-RS) and PSP-parkinsonism (PSP-P) in comparison with Parkinson disease (PD) patients, using MRPI (Magnetic Resonance Parkinsonism Index), and MRPI 2.0.MethodsFifteen PSP-RS patients (disease duration, y, mean ± SD: 2.5 ± 1.1), 16 PSP-P patients (disease duration, y, mean ± SD: 6.5 ± 3.2) and 19 PD patients (disease duration, y, mean ± SD: 3.2 ± 2.3) were enrolled. All patients underwent clinical assessment and MRI at baseline, 1-year, and 2-year follow-up. MRPI, MRPI 2.0 and clinical scores over 1 and 2-years were used to evaluate disease progression rate, and to calculate sample sizes required to power placebo-controlled trials.ResultsAll groups showed increased clinical motor scores over time whereas only PSP groups had increased MRPI and MRPI 2.0 values over T1 and T2 intervals. The percentage increase over 1 and 2-years of MRPI and MRPI 2.0 values was significantly higher in PSP groups than in PD group, and in PSP-RS than in PSP-P patients while no difference between patient groups was observed when clinical motor scores were considered. Sample size estimates showed that MRPI 2.0 performed better than MRPI and clinical scales. Treatment trials with MRPI 2.0 could be performed over 2-years both in PSP-RS and PSP-P with a sample size per treatment arm of 89 and 170 patients, respectively.ConclusionsOur results demonstrate that MRPI 2.0 was more powerful than MRPI and clinical motor scales in evaluating PSP progression, and in providing the best sample size estimates for clinical trials.     

Effects of dyskinesias in Parkinson''s disease on quality of life and health-related costs: a prospective European study

The treatment of Parkinson's disease (PD) with l-DOPA leads to involuntary movements (dyskinesias). This 6-month observational study in three European countries in PD patients with various degrees of motor complications examined the effects of dyskinesias on the quality of life (QoL) of patients and health care costs. Retrospective and prospective health economic data were collected, and QoL of patients was measured using the Short Form-36 (SF-36) and the PD Quality of Life (PDQL) Scale. Regression analysis was used to estimate the adjusted effects of dyskinesias on QoL and costs, whilst accounting for the potentially confounding effects of disease progression, motor fluctuations and country. Increasing dyskinesia scores on either the Unified PD Rating Scale or the Goetz Dyskinesia Rating Scale were associated with significant reductions in QoL scores on the SF-36 and PDQL Scale. Increasing dyskinesia severity was also associated with increased depression scores on the Montgomery-Asberg Depression Rating Scale along with significant increases in health care costs. The effects of dyskinesia on QoL, depression and costs decreased but remained significant after adjustment for the confounding effects of disease progression and motor fluctuations. In conclusion, dyskinesias may adversely affect QoL and increase health care costs in patients with PD. Future studies should evaluate the potentially beneficial effects in terms of QoL and health care costs of strategies to delay the onset of, or the treatment of, dyskinesias.     

Caregiver-burden in parkinson's disease is closely associated with psychiatric symptoms, falls, and disability

The majority of care of patients with Parkinson's disease (PD) is provided by informal caregivers; their caregiving not only offers physical and emotional support for patients but also plays a large economic role and prevents early nursing home placement. In order to support caregivers in this role, it is necessary to understand the extent of caregiver-burden and factors associated with increased caregiver-burden and distress. We therefore conducted a postal survey in 123 caregivers of patients with PD to assess caregiver-burden and factors associated with it. The majority of caregivers were female (66%). Over 40% of caregivers indicated that their health had suffered as a result of caregiving, almost half had increased depression scores, and two-thirds reported that their social life had suffered. After adjustment of disease duration, there was no difference in caregiver-burden between younger and older caregivers, or between male and female caregivers. Caregiver-burden increased with increasing disability and symptoms of PD, particularly with mental health problems such as depression, hallucinations, or confusion, and with falls. Caregiver-burden scores also correlated significantly with the patients' depression and quality of life scores, and with caregivers' own satisfaction with their marital and sexual relationship. We conclude that more attention should be paid to caregivers' emotional and physical health, particularly in advancing PD with psychiatric complications and falls. These findings also demonstrate that caregiver and patient quality of life are closely linked and emphasize the importance of including caregiver-burden among the problems associated with PD in order to improve patient and caregiver lives.