Validity of a mailed epidemiological questionnaire and physical self-assessment in Parkinson's disease

Current Perspectives on the Assessment and Management of Gait Disorders in Parkinson's Disease

Gait dysfunction is a key defining feature of Parkinson's disease (PD), and is associated with symptoms of freezing and an increased risk of falls. In this narrative review, we cover the putative mechanisms of gait dysfunction in PD, the assessment of gait abnormalities, and the management of symptoms caused by the inherent difficulty in walking. Our understanding of the causes of gait problems in PD has progressed in recent times, moving from neurocognitive theory to correlates of affected neuronal pathways. In particular, this can be shown to correspond with abnormalities in responses to dual-task paradigms and dysfunction in cholinergic signaling. Great progress has been made in the sophistication and precision of gait assessment; however, it has firmly remained in the research domain. There is significant momentum behind wearable technologies that can be used by patients in their own environment, acting as digital biomarkers that can not only reflect progression but also independently discriminate PD from non-PD individuals. The treatment of gait dysfunction has historically relied on physical therapies and training combined with a view to mitigating the impact of such consequences as falls. Pharmacological therapies that are the mainstay of treatment in PD have tended to address symptoms like bradykinesia; however, optimization of dopaminergic therapies likely has a positive effect on quality of gait. Other targets have been assessed with the goal of improving gait, of which medications that improve cholinergic signaling appear most promising. Neuromodulation techniques are increasingly used in the form of deep-brain stimulation; however, standard targets, such as the globus pallidus interna, have a modest effect on gait. Considerable benefit has been seen through targeting the pedunculopontine nucleus, and a dual-target approach may be warranted. Stimulation of the spinal cord and brain through direct or magnetic approaches has been assessed, but requires further evidence.

A Practical Measurement of Parkinson's Patients Gait Using Simple Walker-Based Motion Sensing and Data Analysis

We present personal aid for mobility and monitoring (PAMM II), an instrumented walker for Parkinson's disease (PD) patients' gait monitoring. The objective of the walker is to aid in the diagnosis and monitoring of PD progression as well as the effects of clinical treatment and rehabilitation. In contrast to existing devices, the walker is a low-cost solution that is simple to operate and maintain, requiring no adjustments, special usage instructions, or infrastructure. This preliminary study reports on the efficiency, reliability, and accuracy of PAMM II when used to evaluate 22 PD patients and 20 control individuals. All subjects walked two prescribed paths while pushing the walker, and their kinematic motion signals were automatically collected by the walker. Feature derivation from the walker's signals was followed by combinations of two classical feature selection methods and two learning algorithms, with the objective of discriminating PD patients from control subjects. Sensitivity and specificity scores of 91% and 95% were achieved for the first walking protocol, whereas discrimination over the second walking protocol produced sensitivity and specificity scores of 96% and 100%. These preliminary results provide insight as to the usefulness of PAMM II and its data processing algorithms for the assessment of PD patients' condition.

A New Evolutionary Algorithm-Based Home Monitoring Device for Parkinson's Dyskinesia

Parkinson's disease (PD) is a neurodegenerative movement disorder. Although there is no cure, symptomatic treatments are available and can significantly improve quality of life. The motor, or movement, features of PD are caused by reduced production of the neurotransmitter dopamine. Dopamine deficiency is most often treated using dopamine replacement therapy. However, this therapy can itself lead to further motor abnormalities referred to as dyskinesia. Dyskinesia consists of involuntary jerking movements and muscle spasms, which can often be violent. To minimise dyskinesia, it is necessary to accurately titrate the amount of medication given and monitor a patient's movements. In this paper, we describe a new home monitoring device that allows dyskinesia to be measured as a patient goes about their daily activities, providing information that can assist clinicians when making changes to medication regimens. The device uses a predictive model of dyskinesia that was trained by an evolutionary algorithm, and achieves AUC>0.9 when discriminating clinically significant dyskinesia.

Computational approaches for understanding the diagnosis and treatment of Parkinson's disease

This study describes how the application of evolutionary algorithms (EAs) can be used to study motor function in humans with Parkinson's disease (PD) and in animal models of PD. Human data is obtained using commercially available sensors via a range of non-invasive procedures that follow conventional clinical practice. EAs can then be used to classify human data for a range of uses, including diagnosis and disease monitoring. New results are presented that demonstrate how EAs can also be used to classify fruit flies with and without genetic mutations that cause Parkinson's by using measurements of the proboscis extension reflex. The case is made for a computational approach that can be applied across human and animal studies of PD and lays the way for evaluation of existing and new drug therapies in a truly objective way.

Columbia University Assessment of Disability in Essential Tremor (CADET): methodological issues in essential tremor research

Essential tremor (ET) is one of the most prevalent neurological disorders, affecting between 0.4 and 3.9% of the population. As there have been few studies of the functional impact of ET, knowledge of this area is limited. One study relied on subjective reports of tremor severity while a second focused on issues relating to treatment. Knowledge about the functional impact of ET is important for the valid assessment of efficacy in therapeutic trials as well as the diagnosis of ET in genetic and epidemiological studies. In order to examine the issue of functional disability in ET in greater detail, we designed the Columbia University Assessment of Disability in Essential Tremor (CADET). The critical elements of the study design have not been consistently applied to ET research to date. We describe this novel study.

Validation of 24-hour ambulatory gait assessment in Parkinson's disease with simultaneous video observation

Background

Parkinson's disease (PD) is a neurodegenerative disorder resulting in motor disturbances that can impact normal gait. Although PD initially responds well to pharmacological treatment, as the disease progresses efficacy often fluctuates over the course of the day, and clinical management would benefit from long-term objective measures of gait. We have previously described a small device worn on the shank that uses acceleration and angular velocity sensors to calculate stride length and identify freezing of gait in PD patients. In this study we extend validation of the gait monitor to 24-h using simultaneous video observation of PD patients.

Methods

A sleep laboratory was adapted to perform 24-hr video monitoring of patients while wearing the device. Continuous video monitoring of a sleep lab, hallway, kitchen and conference room was performed using a 4-camera security system and recorded to hard disk. Subjects (3) wore the gait monitor on the left shank (just above the ankle) for a 24-h period beginning around 5 pm in the evening. Accuracy of stride length measures were assessed at the beginning and end of the 24-h epoch. Two independent observers rated the video logs to identify when subjects were walking or lying down.

Results

The mean error in stride length at the start of recording was 0.05 m (SD 0) and at the conclusion of the 24 h epoch was 0.06 m (SD 0.026). There was full agreement between observer coding of the video logs and the output from the gait monitor software; that is, for every video observation of the subject walking there was a corresponding pulse in the monitor data that indicated gait.

Conclusions

The accuracy of ambulatory stride length measurement was maintained over the 24-h period, and there was 100% agreement between the autonomous detection of locomotion by the gait monitor and video observation.

Long-term monitoring of gait in Parkinson's disease

A new system for long-term monitoring of gait in Parkinson's disease (PD) has been developed and validated. The characteristics of every stride taken over 10-h epochs were acquired using a lightweight ankle-mounted sensor array that transmitted data wirelessly to a small pocket PC at a rate of 100 Hz. Stride was calculated from the vertical linear acceleration and pitch angular velocity of the leg with an accuracy of 5 cm. Results from PD patients (5) demonstrate the effectiveness of long-term monitoring of gait in a natural environment. The small, variable stride length characteristic of Parkinsonian gait, and fluctuations of efficacy associated with levodopa therapy, such as delayed onset, wearing off, and the 'off/on' effect, could reliably be detected from long-term changes in stride length.

Ambulatory motor assessment in Parkinson's disease

We developed an algorithm that distinguishes between on and off states in patients with Parkinson's disease during daily life activities. Twenty-three patients were monitored continuously in a home-like situation for approximately 3 hours while they carried out normal daily-life activities. Behavior and comments of patients during the experiment were used to determine the on and off periods by a trained observer. Behavior of the patients was measured using triaxial accelerometers, which were placed at six different positions on the body. Parameters related to hypokinesia (percentage movement), bradykinesia (mean velocity), and tremor (percentage peak frequencies above 4 Hz) were used to distinguish between on and off states. The on-off detection was evaluated using sensitivity and specificity. The performance for each patient was defined as the average of the sensitivity and specificity. The best performance to classify on and off states was obtained by analysis of movements in the frequency domain with a sensitivity of 0.97 and a specificity of 0.97. We conclude that our algorithm can distinguish between on and off states with a sensitivity and specificity near 0.97. This method, together with our previously published method to detect levodopa-induced dyskinesia, can automatically assess the motor state of Parkinson's disease patients and can operate successfully in unsupervised ambulatory conditions.

Dieldrin-induced neurotoxicity: relevance to Parkinson's disease pathogenesis

Parkinson's disease (PD) is increasingly recognized as a neurodegenerative disorder strongly associated with environmental chemical exposures. Recent epidemiological data demonstrate that environmental risk factors may play a dominant role as compared to genetic factors in the etiopathogenesis of idiopathic Parkinson's disease. Identification of key genetic defects such as alpha-synuclein and parkin mutations in PD also underscores the important role of genetic factors in the disease. Thus, understanding the interplay between genes and environment in PD may be critical to unlocking the mysteries of this 200-year-old neurodegenerative disease. Pesticides and metals are the most common classes of environmental chemicals that promote dopaminergic degeneration. The organochlorine pesticide dieldrin has been found in human PD postmortem brain tissues, suggesting that this pesticide has potential to promote nigral cell death. Though dieldrin has been banned, humans continue to be exposed to the pesticide through contaminated dairy products and meats due to the persistent accumulation of the pesticide in the environment. This review summarizes various neurotoxic studies conducted in both cell culture and animals models following dieldrin exposure and discusses their relevance to key pathological mechanisms associated with nigral dopaminergic degeneration including oxidative stress, mitochondrial dysfunction, protein aggregation, and apoptosis.

Wireless real-time electronic data capture for self-assessment of motor function and quality of life in Parkinson's disease

Frequent assessment of the symptoms in Parkinson's disease (PD) is important in both clinical and experimental settings, especially when motor fluctuations are present. Patient diaries are increasingly used in studies, allowing patients to stay in their home environments. However, traditional paper diaries may not reflect reality because of a lack in compliance or retrospective data entries. This study presents a comparison between paper diaries and a new method, real-time data capture with a hand-held computer (electronic diary). Twenty patients with PD diagnosed at least 5 years previously were randomly assigned to use either a paper diary or an electronic diary on 8 days during 1 month. Questions were answered every 2 hours over a 12-hour period on each day. Median compliance was 88% with the electronic diary and 98% with the paper diary, although strict compliance to the scheduled times by patients using the paper diary was 78%. Neither age nor earlier experience with computers affected the patient's ability to use the electronic diary. Electronic diaries can be used for self-assessment of PD symptoms. The real-time feature provides fast access to clean data with knowledge of true compliance.

Designing neuroprotection trials in Parkinson's disease

A major goal of the neuroscience community is to develop neuroprotective treatment strategies that will slow or forestall the progression of Parkinson's disease, one of the most common adult-onset neurodegenerative disorders, affecting approximately 1 million people in North America. Although prior research to identify neuroprotective interventions has not been conclusive, recent advances in the understanding of the pathogenesis of Parkinson's disease, including the development of relevant animal models, provide the opportunity for rational clinical trials to assess neuroprotective treatments.

Movement parameters that distinguish between voluntary movements and levodopa-induced dyskinesia in Parkinson's disease

It is well known that long-term use of levodopa by patients with Parkinson's disease causes dyskinesia. Several methods have been proposed for the automatic, unsupervised detection and classification of levodopa induced dyskinesia. Recently, we have demonstrated that neural networks are highly successful to detect dyskinesia and to distinguish dyskinesia from voluntary movements. The aim of this study was to use the trained neural networks to extract parameters, which are important to distinguish between dyskinesia and voluntary movements. Thirteen patients were continuously monitored in a home-like situation performing in about 35 daily life tasks for a period of approximately 2.5 h. Behavior of the patients was measured using triaxial accelerometers, which were placed at six different positions of the body. A neural network was trained to assess the severity of dyskinesia. The neural network was able to assess the severity of dyskinesia and could distinguish dyskinesia from voluntary movements in daily life. For the trunk and the leg, the important parameters appeared to be the percentage of time that the trunk or leg was moving and the standard deviation of the segment velocity of the less dyskinetic leg. For the arm, the combination of the percentage of time, that the wrist was moving, and the percentage of time, that a patient was sitting, explained the largest part of the variance of the output. Dyskinesia differs from voluntary movements in the fact that dyskinetic movements tend to have lower frequencies than voluntary movements and in the fact that movements of different body segments are not well coordinated in dyskinesia.

Automatic assessment of levodopa-induced dyskinesias in daily life by neural networks

We developed an objective and automatic procedure to assess the severity of levodopa-induced dyskinesia (LID) in patients with Parkinson's disease during daily life activities. Thirteen patients were continuously monitored in a home-like situation for a period of approximately 2.5 hours. During this time period, the patients performed approximately 35 functional daily life activities. Behavior of the patients was measured using triaxial accelerometers, which were placed at six different positions on the body. A neural network was trained to assess the severity of LID using various variables of the accelerometer signals. Neural network scores were compared with the assessment by physicians, who evaluated the continuously videotaped behavior of the patients off-line. The neural network correctly classified dyskinesia or the absence of dyskinesia in 15-minute intervals in 93.7, 99.7, and 97.0% for the arm, trunk, and leg, respectively. In the few cases of misclassification, the rating by the neural network was in the class next to that indicated by the physicians using the AIMS score (scale 0-4). Analysis of the neural networks revealed several new variables, which are relevant for assessing the severity of LID. The results indicate that the neural network can accurately assess the severity of LID and could distinguish LID from voluntary movements in daily life situations.

Activity-based diary for Parkinson's disease

The objective of this study was to develop a Parkinson's disease diary that evaluates a patient's difficulties in performing activities as a substitute for the amount of "on"- and "off"-time and to assess its clinimetric qualities. In this study, 84 patients with Parkinson's disease kept a diary for 2 or 3 periods of 5 days. Daily, five items were recorded across 11 time periods. Patients simultaneously recorded "on-off" in the traditional way. The diary was easily understood, and median recording time was 5-10 minutes a day. Clinimetric analysis showed that the diary could be reduced successfully to 3 days, in which five items (walking, transfers, manual activities, dyskinesias, and sleep) with four response options (no, slight, moderate, and severe difficulty) were assessed seven times daily. Sumscores of the first three items accurately predicted being "on" or "off" in 93% of the cases, making separate scoring of "on" and "off" unnecessary. The diary was internally consistent and showed good reproducibility. Construct validity with external measures was adequate, and comparisons between patients grouped by disease severity and by degree of fluctuations revealed significant differences in the expected directions. Taken together, this Parkinson's disease diary has a sound clinimetric basis, provides information on the extent of perceived disability, and thereby accurately reflects the severity of "off"-periods and the variability of motor fluctuations.

Detection and assessment of the severity of levodopa-induced dyskinesia in patients with Parkinson's disease by neural networks

Levodopa-induced dyskinesias (LID) in Parkinson's disease (PD) have remained a clinical challenge. We evaluated the feasibility of neural networks to detect LID and to quantify their severity in 16 patients with PD at rest and during various activities of daily living. The movements of the patients were measured using four pairs of accelerometers mounted on the wrist, upper arm, trunk, and leg on the most affected side. Using parameters obtained from the accelerometer signals, neural networks were trained to detect and to classify LID corresponding to the modified Abnormal Involuntary Movement Scale. Important parameters for classification appeared to be the mean segment velocity and the cross-correlation between accelerometers on the arm, trunk, and leg. Neural networks were able to distinguish voluntary movements from LID and to assess the severity of LID in various activities. Based on the results in this study, we conclude that neural networks are a valid and reliable method to detect and to assess the severity of LID corresponding to the modified Abnormal Involuntary Movement Scale.

An ambulatory dyskinesia monitor

OBJECTIVES

New treatments are now becoming available for the management of levodopa induced dyskinesias in Parkinsons's disease. However, assessment of their efficacy is limited by the inadequacies of current methods of dyskinesia measurement. The objective was to develop and validate a portable device capable of objectively measuring dyskinesias during normal daily activities.

METHODS

A portable device was developed based on a triaxial accelerometer, worn on the shoulder, and a data recorder that can record levodopa induced dyskinesias. A computer program plots raw acceleration and acceleration over 0.5 Hz frequency bands against time. The acceleration in the different bands can then be compared with the raw acceleration trace, enabling identification and exclusion of confounding activities such as tremor and walking, which have a characteristic appearance on the trace. The validity of this device was assessed on 12 patients and eight age matched controls by comparing accelerations in the 1-3 Hz frequency band with established clinical dyskinesia rating scales. While wearing the monitor, subjects were videorecorded sitting and during dyskinesia provocation tasks, including mental activation tasks, eating, drinking, writing, putting on a coat, and walking. The dyskinesias were graded with both modified abnormal involuntary movement (AIM) and Goetz scales. The clinical ratings were then compared with the mean acceleration scores.

RESULTS

Acceleration in the 1-3 Hz frequency band correlated well against both scales, during all individual tasks. Acceleration produced by normal voluntary activity (with the exception of walking, which produced large accelerations, even in controls) was small compared with dyskinetic activity. With walking excluded, the mean acceleration over the rest of the recording time correlated strongly with both the modified AIM (Spearman's rank (r=0.972, p<0.001) and Goetz (r=0.951, p<0.001) scales.

CONCLUSIONS

This method provides an accurate, objective means for dyskinesia assessment, and compares favourably with established methods currently used.

A review of the assessment of dyskinesias

Dyskinesias are most prevalent in patients with Huntington's disease (HD), patients with Parkinson's disease (PD) who have received chronic levodopa therapy, and in patients who have been treated with neuroleptics (tardive dyskinesia ITD]). Recent therapeutic developments have fueled a growing interest in the clinimetrics of dyskinesias. For dyskinesias in HD, few rating scales are available, but data on validity, reliability, and responsiveness are scarce. Only the interrater reliability of facial dyskinesias has been evaluated and found to be low. Many subjective rating scales for dyskinesias in PD exist, but only the Dyskinesia Rating Scale has undergone sufficient clinimetric evaluation. For TD, numerous rating scales are available, many of them with ample data on reliability and validity. Objective assessment of dyskinesias has been attempted with a number of techniques. All these methods require a laboratory setting, rendering them susceptible to influence of stress. Moreover, they provide only a momentary assessment of dyskinesia severity and fail to take into account diurnal fluctuations. In view of the methodologic shortcomings in the assessment of dyskinesias, more effort needs to be put into strengthening currently available modes of assessment or designing new ones. In the future ambulatory accelerometry might prove to be of value in this field.

Efficacy of a patient-training videotape on motor fluctuations for on-off diaries in Parkinson's disease

Patient on-off diaries are used in clinical trials, but a method to assure agreement between patient and examiner has never been developed. We tested whether a patient-teaching tape increased the rate of agreement between patient diary ratings and simultaneous neurologic assessment by a trained professional. A total of 32 consecutive patients who had Parkinson's disease with motor fluctuations independently completed a 4-h on-off diary (nine ratings) at the same time as an examiner. Those with < 80% agreement with the examiner (n = 20) were randomized to view either a training tape that showed motor fluctuations (experimental group) or-another videotape of general patient educational material (control group). All patients then underwent the same 4-h assessment of motor fluctuations. To test for long-term retention, they returned 1 month later and, without reviewing the videotape, underwent a final 4-h correlation assessment. After the training tape, the experimental group showed significant improvement, whereas the control group showed no improvement. Furthermore, another month later, the improvement in the experimental group was retained. Based on these findings, we suggest that future clinical trials assessing motor fluctuations incorporate this tape into their basic methodology.

Controversies in pallidal surgery

Posteroventral pallidotomy (PVP) has gained a worldwide acceptance after its reintroduction by Laitinen et al. in 1992 (56) and many studies have since been published. A review of the recent literature reveals that there is variation in the clinical indications for this procedure, the surgical technique used and the assessment of results. There is no uniform practice in the choice of the anatomical target point within the globus pallidus, the imaging of the target structure, the intraoperative assessment of the physiological target and the mode of evaluation of the surgical results. Although some neurosurgeons advocate that the lesion should be in the lateral pallidum, the majority insist it should be in the medial pallidum. It is shown here that, as long as the lesion is made at the posterior and ventral parts of the globus pallidus, it will necessarily include aspects of both medial and lateral posteroventral pallidum. There is a common agreement on the effectiveness of pallidal surgery on the L-dopa induced dyskinesias, but, its long-term effects on tremor, akinesia, freezing of the gait and other genuine parkinsonian symptoms need more extensive evaluation. The assessment of the outcome of pallidal surgery in terms of the patient's disability, quality of life and coping abilities following surgery seems to have been neglected.

Reliability of patient completion of the historical section of the Unified Parkinson's Disease Rating Scale

Evaluating the reliability of self-assessed disability in patients with Parkinson's disease (PD) is important for therapeutic trials epidemiologic surveys. This is the first study to examine the interrater reliability between physician and patient in the historical section of the Unified Parkinson's Disease Rating Scale (UPDRS). Thirty consecutive subjects with idiopathic PD self-administered the historical section of a modified UPDRS. This instrument was then readministered to these 30 subjects by a neurologist. Interobserver reliability was assessed with the weighted kappa statistic (kw). The kw for each of the 17 items in the historical section of the UPDRS ranged from 0.63 to 1.0 (moderate to excellent agreement). Total kw = 0.83 (95% confidence interval = 0.79-0.87). There were no correlations between kw and age, disease duration, dose of levodopa, Hoehn and Yahr score, Schwab and England score, or modified Mini-Mental State score. Nondemented subjects with PD may reliably assess their level of disability by self-administering the historical section of the UPDRS. This has important implications for the reliable use of self-administered disability instruments for clinical research.

Prevalence of a history of shaking in persons 65 years of age and older: diagnostic and functional correlates

The purpose of this study was to determine the prevalence and functional and diagnostic correlates of reported shaking in the community-dwelling elderly. We conducted a standardized neurological evaluation of 1,056 nondemented Medicare recipients in Washington Heights-Inwood, Northern Manhattan (New York). Of 1,056 patients, 108 reported shaking (10.2%). The prevalence of reported shaking did not increase with age. It did differ between ethnic groups, but when adjusted for depression and score on the Schwab and England Activities of Daily Living (ADL) scale, this difference was insignificant. The age-adjusted prevalence was similar for women and men. Neurological examination of the 108 who reported shaking showed that 8.3% had tremor at rest, 17.6% had tremor with action, 5.6% had dyskinesia or chorea, and an additional 28.7% had various problems in coordination or movement. The remaining 39.8% had neither tremor nor problems in coordination or movement. Only 2.9% of individuals with reported shaking had Parkinson's disease (PD), 8.7% had essential tremor, and 2.1% had oral-buccal-lingual dyskinesia. Of the remaining 86.3%, 29 (31%) had no identifiable medical condition. Those who reported shaking were less independent with ADLs, regardless of presence of tremor on examination. Shaking is commonly reported by the community-dwelling elderly. It does not necessarily identify individuals with essential tremor and PD, and is related to decreased independence in ADLs.

Rating impairment and disability in Parkinson's disease: evaluation of the Unified Parkinson's Disease Rating Scale

Although the Unified Parkinson's Disease Rating Scale (UPDRS) is widely used to monitor disease progression and drug efficacy, no attempts have been made to evaluate its scientific and clinical quality. Poor clinical sensibility of items in the activities of daily living (ADL) section and redundancy of items in the motor examination (ME) section prompted us to determine if the number of items in these sections could be reduced to a smaller, equally sensitive set that would describe the data as reliably as did the original set of items. Therefore, we assessed 111 patients with idiopathic Parkinson's disease on the UPDRS and Hoehn and Yahr staging scales. Our results show that the ADL (13 items) and ME (14 items) sections can be reduced to 8 items each without loss of reliability or validity. Our report is preliminary and needs validation.

Interobserver reliability between neurologists in training of Parkinson's disease rating scales. A multicenter study

A multicenter study has been conducted to determine the interobserver reproducibility of four of the most frequently used rating scales for Parkinson's disease: the Columbia University Rating Scale (CURS) and the Webster Rating Scale (WRS), both for assessing clinical signs; the Northwestern University Disability Scale (NUDS); and the Hoehn and Yahr staging. Four resident neurologists, inexperienced in the use of the four scales, independently examined 48 parkinsonian patients. The extent to which their assessments agreed was determined by calculating the Cohen k index after the scores had been recodified. The physicians' scores agreed substantially for the CURS and the Hoehn and Yahr scale, while those for the NUDS and the WRS agreed only moderately. Analysis of individual item scores within the scales suggests improvements that would offer greater interobserver consistency.

Controlled-release levodopa/benserazide (Madopar HBS): clinical observations and levodopa and dopamine plasma concentrations in fluctuating parkinsonian patients

In five levodopa (L-dopa)-treated patients with Parkinson's disease with severe fluctuations of motor performance, plasma L-dopa as well as dopamine levels were measured during 2 days, first under optimal standard L-dopa with peripheral decarboxylase inhibitor (PDI) and then after a dose adjustment period using slow-release L-dopa/benserazide (Madopar HBS) in an open inpatient trial. Three patients benefited from the slow-release preparation; two patients deteriorated with a tendency to have an unpredictable response, a delay to turn "on" with the first dose in the morning, as well as an increase in dyskinesia corresponding to L-dopa cumulation during the day. These problems were subsequently also seen during the follow-up period of 1 year in those patients who benefited from Madopar HBS as inpatients. This might indicate that patient compliance is more difficult with the new formulation. After 1 year all patients had returned to their previous standard L-dopa/PDI treatment. L-Dopa levels continued to fluctuate, but to a lesser degree with Madopar HBS. The equivalent L-dopa dosage had to be increased by 56% (29-100%) with Madopar HBS while mean dopamine levels increased in four patients (by 47-257%) without the occurrence of peripheral side-effects. This implies that with the new formulation more L-dopa is metabolized to dopamine and explains the necessity to increase the equivalent L-dopa dosage.

Follow-up study of early-life protective and risk factors in Parkinson's disease

Previous studies suggest that Parkinson's disease (PD) is negatively associated with early-life intake of vitamin E-rich foods and positively associated with rural experience. Using a new survey design, we attempted to confirm and extend these results. We gave a telephone questionnaire to 106 patients with PD and to their spouses as controls. It assessed premarital consumption of 31 foods of various vitamin E content, vitamin supplements, and exposure to rural living. Respondents rated food consumption with respect to what they perceived as the average for their sex and age at that time. We found female patients with PD less likely than spouses to have eaten "peanuts and peanut butter" (p less than .05), which are high in vitamin E. "Salad with dressing," also high in vitamin E, gave a similar result (p less than .05) for a male-predominant patient group. Separate comparison of male controls with female controls ruled out sex-related preferences as the explanation of our findings. Patients had more extensive rural experience and were more likely to have frequently sprayed pesticides (p less than .05) than had controls. Our results justify further investigations into early-life vitamin E intake, pesticides, and neurotoxins associated with rural life.