Evaluating the evaluations: or how to weigh the scales of parkinsonian disability

Comparison of Quantitative Electroencephalogram During Sleep in Depressed and Non-Depressed Patients with Parkinson's Disease

BACKGROUND Depression is one of the most important factors affecting quality of life in Parkinson's patients. Most research on Parkinson's disease with depression has focused on neuroimaging, and there have been few quantitative electroencephalogram studies. Sleep is a biomarker for depression; therefore, the aim of this study was to identify differences in quantitative electroencephalograms during sleep in depressed and non-depressed patients with Parkinson's disease. MATERIAL AND METHODS We assessed 38 Parkinson's disease patients (26 depressed patients, 12 non-depressed patients) and 20 normal subjects using the Geriatric Depressive Scale for Depressive Symptoms and quantitative electroencephalogram analysis of amplitude of different frequency bands in different sleep stages using Met-lab software and Fast Fourier Transformation. RESULTS Non-rapid eye moment 2 and the Frontal 4 Electrode amplitude in the delta and theta ranges were progressively and significantly greater in the depressed-Parkinson's disease group (p<0.05) than in the control group. In the depressed Parkinson's disease group, from the comparison of non-rapid eye moment 2 and rapid eye moment, in Frontal 4 the amplitude in the delta ranges of non-rapid eye moment 2 was greater than in the non-depressed group, and in Central 3, Central 4, Occipital 1, and Occipital 2, the amplitudes in the beta ranges of rapid eye moment were greater (p<0.05) than in the non-depressed group. CONCLUSIONS The higher amplitude in theta in frontal areas in NREM2 and the higher amplitude in beta in parietal and occipital lobe areas in REM relative to NREM2 were significantly different in depressed and non-depressed patients with Parkinson's disease.

Age-related slowing and fragmentation of a complex movement quantified by optoelectronic kinesiology

Computer-assisted optoelectronic movement analysis has opened a new field in quantitative laboratory studies of motor function in freely moving humans. In order to establish a method for objective and quantitative documentation of age-related change of a complex movement, a lifting task composed of rising, gait and arm movements was designed. The motor performance of 44 healthy subjects in three age groups was recorded optoelectronically. The change in motor function in the age interval of 40-75 years was mainly due to slower motor performance. In a majority of the subjects aged 85, a movement fragmentation also occurred, indicating deficient co-ordination of rising, gait and arm movements in this age group. The method was found to be well suited to clinical studies of movement pattern and disturbances in elderly subjects. The design of specific tests measuring different aspects of the age-related change in motor function may be of value for sociomedical planning of care and prevention.

Non-motor symptoms of Parkinson's disease A review…from the past

Although Parkinson's disease (PD) has been classically defined as a motor disorder, a range of non-motor symptoms (NMS) including cognitive, mood, autonomic and sleep disturbances occur with the passage of time. Although it seems that the non-motor aspect of PD is a recent observation, classic authors (James Parkinson, Charcot, Gowers, Oppenheim and Wilson) had described many NMS including pain, fatigue, bladder dysfunction, cognitive decline and delusion. In this review we have collated the classic literature of NMS in PD.

The Effect of Balance Training by Tetraks Interactive Balance System on Balance and Fall Risk in Parkinson's Patients: A Report of Four Cases

This pilot study aimed to investigate the effect of balance training by Tetraks Interactive Balance System (TIBS) on balance and fall risk in patients with mild to moderate Parkinson's disease. Four patients with Parkinson's disease between the ages of 56 and 70 years (61.25±6.70) were applied balance training for 3 weeks by TIBS. Sociodemographic features and physical properties of the subjects were recorded. Their motor performance was evaluated by the Unified Parkinson's Disease Rating Scale (UPDRS), balance was measured using the Berg Balance Scale (BBS), Functional Reach Test (FRT), Timed Up and Go Test (TUG), and the Standing on One Leg Balance Test (SOL) and, their fall risks were evaluated by TIBS. Evaluations were performed twice, before and after treatment. Following training, Parkinson's patients showed improvements in UPDRS, TUG, BBS, FRT, SOL and fall risk. Balance training by TIBS has positive effects on balance and decreases fall risk in Parkinson's disease patients.

Rate of clinical progression in Parkinson's disease. A prospective study

Few prospective data on the clinical progression of Parkinson's disease (PD) in patient groups outside treatment trials in selected patients are available, and controversy exists on the rate of clinical disease progression with advancing disease. In this study, we investigated the rate of clinical progression of PD in a clinic-based sample of 145 patients over 1 year and in a community-based sample of 124 patients over 4 years. Depending on the sample and clinical scale used, mean deterioration of motor and disability scores ranged from 2.4 to 7.4% of the maximum possible score per year, and standard deviations indicated that there was considerable variability of progression rates between individuals. The progression of motor scores decreased with follow-up over 4 years and significantly decreased in more advanced disease stages. Deterioration of disability scores did not differ between disease stages; this may reflect the increasing rate of disease complications, which contribute to increasing disability in addition to motor impairment alone, in more advanced disease. Thus, motor fluctuations, hallucinations, depression, memory problems, and bladder symptoms were all reported more often at follow-up in the community-based sample (all P < 0.01), and dyskinesias, motor fluctuations, falls, and hallucinations were more common and cognitive and depression scores worse in higher disease stages in the clinic-based sample (all P < 0.001). We conclude that progression of motor scores in PD decreases with advancing disease in PD. However, disability continues to deteriorate with advancing disease and with the development of disease complications that are likely to be related to additional extrastriatal pathology.

Memory Deficits in Parkinson’s Disease

The purpose of this study was to investigate deficits in recognition, recall, and prospective memory among Parkinson's disease (PD) patients, and to ascertain whether task difficulty and disease severity moderate these deficits. Comparisons were made between 41 nondemented PD participants, divided into early-stage and advanced-stage groups, and 41 matched controls. PD participants exhibited deficits in recognition, recall, and prospective memory. The advanced-stage PD group produced greater deficits than the early-stage PD group in all tasks, suggesting that these deficits increase in step with overall disease severity. The results of the task difficulty manipulation provide a partial explanation for the inconsistencies in the literature concerning the existence of recognition memory deficits in PD.

Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations

The Movement Disorder Society Task Force for Rating Scales for Parkinson's disease (PD) prepared a critique of the Hoehn and Yahr scale (HY). Strengths of the HY scale include its wide utilization and acceptance. Progressively higher stages correlate with neuroimaging studies of dopaminergic loss, and high correlations exist between the HY scale and some standardized scales of motor impairment, disability, and quality of life. Weaknesses include the scale's mixing of impairment and disability and its non-linearity. Because the HY scale is weighted heavily toward postural instability as the primary index of disease severity, it does not capture completely impairments or disability from other motor features of PD and gives no information on nonmotor problems. Direct clinimetric testing of the HY scale has been very limited, but the scale fulfills at least some criteria for reliability and validity, especially for the midranges of the scale (Stages 2-4). Although a "modified HY scale" that includes 0.5 increments has been adopted widely, no clinimetric data are available on this adaptation. The Task Force recommends that: (1) the HY scale be used in its original form for demographic presentation of patient groups; (2) when the HY scale is used for group description, medians and ranges should be reported and analysis of changes should use nonparametric methods; (3) in research settings, the HY scale is useful primarily for defining inclusion/exclusion criteria; (4) to retain simplicity, clinicians should "rate what you see" and therefore incorporate comorbidities when assigning a HY stage; and (5) because of the wide usage of the modified HY scale with 0.5 increments, this adaptation warrants clinimetric testing. Without such testing, however, the original five-point scales should be maintained.

Psychosocial problems in Parkinson's disease: evaluation of a disease-specific questionnaire

Our objective was to evaluate the BELA-P-k, a questionnaire for measuring psychosocial problems and need for help in Parkinson's disease (PD) patients. The Belastungsfragebogen Parkinson kurzversion (BELA-P-k) was translated from German into Dutch. It consists of 19 items distributed over four subscales: achievement capability/physical symptoms, fear/emotional functioning, social functioning and partner-bonding/family, with a "Bothered by" (Bb) and a "Need for Help" (NfH) score. The BELA-P-k was tested for cultural differences, relevance, and feasibility in a pilot study (n = 10) and compared in a validation study (n = 54) with the Sickness Impact Profile, the COOP/WONCA Functional Health Assessment Charts and the Loneliness Questionnaire. All questionnaires were administered in person at home, in a prescribed order. The BELA-P-k was completed by 64 patients with PD. The internal-consistency reliability coefficients for the total Bb (0.90) and NfH (0.93) scales were excellent. The internal consistency of the subscales exceeded the 0.70 standard except for the "Bothered by partner-bonding/family scale" (0.61). Almost all BELA-P-k subscales correlated highly (P < 0.001) with the corresponding scales of the standard quality-of-life indices. There was no significant relationship between disease severity (Hoehn and Yahr) and the BELA-P-k. We conclude that the BELA-P-k is a relevant, reliable and valid measure for assessing psychosocial problems and need for help of PD patients.

Reliability of measurements of patient health status: a comparison of physician, patient, and caregiver ratings

The purpose of this preliminary study was to investigate the inter-rater reliability among physician, patient, and caregiver ratings on the Hoehn & Yahr (H & Y) and Schwab & England (S & E) rating instruments. We also examined differences in ratings between patients who attended clinic with and without caregivers (spouses and adult children). Patients and caregivers coming for an appointment at Colorado Neurological Institute were asked to independently complete the H & Y and S & E scales. Physicians rated the patients during the exam. In the group of patients who came to clinic with caregivers, there was significant agreement on both the H & Y and S & E (P<0.001). For patients not accompanied by caregivers, patients rated themselves as more debilitated on the S & E than physicians (P<0.001). Patients without caregivers rated themselves as more functional than patients with caregivers on both scales (P<0.001). Physicians also rated patients without caregivers as more functional on both scales (P<0.001). Results indicated there was consistency among ratings of physicians and patients accompanied by caregivers on both scales. Patients attending clinic alone rated themselves as worse on the S & E than physicians. Patients alone were rated as more functional than patients accompanied by caregivers on both scales regardless of rater.

The internal consistency and validity of the Self-Assessment Parkinson's Disease Disability Scale

OBJECTIVE

To test the consistency and validity of the Self-assessment Parkinson's Disease Disability Scale in patients with Parkinson's disease living at home.

DESIGN

Patients with Parkinson's disease responded to a set of questionnaires. In addition, an observation of the performance of daily activities was carried out on a subgroup.

SETTING AND SUBJECTS

Patients with Parkinson's disease living at home (n = 142).

MEASURES

The Self-assessment Parkinson's Disease Disability Scale (SPDDS), the Hoehn & Yahr Rating Scale (H&Y), and the Sickness Impact Profile (SIP68). The observation concerned nine activities that correspond to items of the SPDDS questionnaire.

RESULTS

Internal consistency of the SPDDS was very high (Cronbach's alpha = 0.97; reliability rho = 0.97). The items of the SPDDS are hierarchical (Loevinger's H = 0.64): patients had least difficulty with 'washing' and 'brushing teeth' and most difficulty with 'turning in bed', 'travelling by public transport' and 'writing a letter'. Validity of the SPDDS was good: the relationship between the SPDDS questionnaire and the H&Y rating scale, the SIP68 and the results of the observation was strong and significant.

CONCLUSION

The SPDDS is a unidimensional instrument measuring disabilities in Parkinson's disease patients living at home.

Chronic electrostimulation of ventroposterolateral pallidum: follow-up

Introduced in 1992, and first published with report of 3 cases in 1994, the ventroposterolateral electrostimulation of the pallidum raised exciting prospects. The follow-up of this new approach will be presented in 19 cases with at least 6 months control, and up to 42 months. The very favorable effects observed in the first series could be confirmed and extended to a larger group of patients during a longer period.

Quality of life in patients with Parkinson's disease: development of a questionnaire

OBJECTIVES

To develop and test a questionnaire for measuring quality of life in patients with Parkinson's disease.

METHODS

An item pool was developed based on the experience of patients with Parkinson's disease and of neurologists; medical literature on the problems of patients with Parkinson's disease; and other quality of life questionnaires. To reduce the item pool, 13 patients identified items that were a problem to them and rated their importance. Items which were most often chosen and rated most important were included in the Parkinson's disease quality of life questionnaire (PDQL). The PDQL consists of 37 items. To evaluate the discriminant validity of the PDQL three groups of severity of disease were compared. To test for convergent validity, the scores of the PDQL were tested for correlation with standard indices of quality of life.

RESULTS

The PDQL was filled out by 384 patients with Parkinson's disease. It consisted of four subscales: parkinsonian symptoms, systemic symptoms, emotional functioning, and social functioning. The internal-consistency reliability coefficients of the PDQL subscales were high (0.80-0.87). Patients with higher disease severity had significantly lower quality of life on all PDQL subscales (P < 0.05). Almost all PDQL subscales correlated highly (P < 0.001) with the corresponding scales of the standard quality of life indices.

CONCLUSION

The PDQL is a relevant, reliable, and valid measure of the quality of life of patients with Parkinson's disease.

Computational analysis of open loop handwriting movements in Parkinson's disease: a rapid method to detect dopamimetic effects

We used a computational analysis of open loop handwriting movements and a clinical rating scale for monitoring the effect of apomorphine in 16 patients with early untreated parkinsonism [subsequently L-DOPA responsive, probable Parkinson's disease (PD)], six patients with long-standing PD with L-DOPA associated motor fluctuations, and seven patients with known L-DOPA unresponsive parkinsonism. Subjects were instructed to write fluently concentric circles of approximately 12 mm in diameter. Movements were recorded for two periods of 3 s each, using a digitizing tablet. Mean peak velocity (Vmax) and mean peak acceleration (Amax) were determined. In addition, two sensitive indices describing the degree of automation of handwriting were derived: (a) NCV, calculated as the mean Number of Changes in direction of Velocity per half circle, and (b) NCA, the mean Number of Changes in the direction of Acceleration. Clinical rating was performed according to the Unified Parkinson's Disease Rating Scale part III (UPDRS III). After apomorphine injection, the patients with early untreated probable PD showed significant improvement of Vmax, Amax, NCV, NCA, and UPDRS III scores. Likewise, the patients with long-standing PD improved significantly in all kinematic parameters and UPDRS III scores. Patients with L-DOPA unresponsive parkinsonism failed to change significantly in any of the parameters tested. These observations suggest that the computer-assisted analysis of automated handwriting movements can be used as an objective quick method for quantifying dopamimetic effects on the kinematics of handwriting movements in parkinsonian patients.

Value and appropriate use of rating scales and apparative measurements in quantification of disability in Parkinson's disease

Despite widespread use in pharmacotherapeutical trials, in the majority of rating scales used in Parkinson's disease (PD) validity, reliability and appropriate use have never been confirmed by statistical data. For this reason 350 unselected PD-pats. were investigated by an extensive standardized test-battery including registration of basis data, Columbia University Rating Scale (CURS), scale for assessment of functional disability (ADL), SCAG-scale, Hoehn & Jahr-scale (HY), mod. Webster step second-test (WSST), Purdue-pegboard, questionnaire for subjective complaints (SC), WDG, LPS1/2, 3/4, 6, 7, 10, clinical assessment of dementia, v. Zerssen-scale and orthostatic hypotension (60 degrees tilt up). For CURS, SCAG and ADL instrumental reliability was calculated by Cronbach's alpha. For CURS, SCAG, ADL and the total data of complete test battery (CTB) principal component analysis (PCA) was performed for data reduction. CURS, SCAG and ADL showed high internal consistency (alpha approximately > or = 0.9). For CURS 5 factors accounting for 66% total variance could be extracted by PCA. They represent gait, rigidity, tremor, right/left dexterity (eigenvalues > 1). For SCAG 3 factors (61% of total variance) representing dementia, depression and change of personality were extracted. For ADL 3 factors (67% of total variance) could be extracted, representing overall functional disability, handwriting and disability by pain. PCA of the CTB identified 8 interpretable factors (66% of total variance) characterizing at least partially the clinical profile of PD: 1. motor disability (assessment by rating-scales) 2. dementia, 3. motor-disability (assessment by apparative measurements), 4. depression, 5. orthostatic hypotension, 6. WDG, 7. tremor and 8. pain. Our data confirm the suitability of the investigated scales and give a rational base for their appropriate use in a sense of data reduction and economical evaluation.

Single-dose L-dopa response in early Parkinson's disease: measurements with optoelectronic recording technique

Twenty-five patients with suspected Parkinson's disease were submitted to optoelectronic movement analysis with the Posturo-Locomotor-Manual (PLM) test before and 60 min after a single dose of L-Dopa. They were then examined clinically for diagnosis. Two patients were excluded due to L-Dopa intolerance. Seventeen of the remaining patients were classified as having Parkinson's disease. The movement time (MT) in the PLM test was increased for all these patients, and they improved their performance after L-Dopa. The degree of improvement was roughly proportional to the pretreatment augmentation of MT in comparison to healthy subjects of the same age. The PLM phase analysis showed a specific disability profile for each individual. Six patients were given diagnoses other than PD. Some improvement was found in one patient with suspected olivopontocerebellar atrophy and one patient with multiple brain injury. Two patients with progressive supranuclear palsy, one with suspected striatonigral degeneration, and one with functional disturbance deteriorated after L-Dopa. In conclusion, truly objective and fully reproducible evaluation of the motor performance before and after a single L-Dopa dose is easily accomplished with computer-assisted modern optoelectronic recording equipment. The technique is a valuable tool for the quantitative measurement of treatment effects and contributes to the differential diagnosis.

A controlled, longitudinal study of dementia in Parkinson's disease

Serial assessments of cognition, mood, and disability were carried out at nine month intervals over a 54 month period on a cohort of 87 patients with Parkinson's disease (PD) and a matched cohort of 50 control subjects. Dementia was diagnosed from data by rigorously applying DSM-III-R criteria. Initially, 6% (5/87) PD patients were demented, compared with none of the 50 control subjects. A further 10 PD patients met the dementia criteria during the follow up period; this was equivalent, with survival analysis, to a cumulative incidence of 19%. With the number of person years of observation as the denominator, the incidence was 47.6/1000 person years of observation. None of the control subjects fulfilled dementia criteria during the follow up period. The patients with PD who became demented during follow up were older at onset of Parkinson's disease than patients who did not become demented, had a longer duration of Parkinson's disease, and were older at inclusion to the study.

Utility of the sickness impact profile in Parkinson's disease

The Sickness Impact Profile (SIP) is a questionnaire consisting of 136 items grouped into 12 categories and two dimensions (physical and psychosocial). To characterize its utility in Parkinson's disease (PD), we administered the SIP to 44 consecutive clinic patients with PD. Compared to 44 age- and sex-matched control subjects, PD patients had their greatest dysfunction in the categories of mobility, communication, and home management. The two items that PD patients most commonly endorsed were, "I am having trouble writing or typing" (75%) and, "My sexual activity is decreased" (61%). In general, these treated PD patients had greater dysfunction in the psychosocial than physical dimensions. Two simple PD-specific scales correlated well with the physical dimension score but less so with the psychosocial dimension, suggesting that the SIP assesses more functional domains than the PD-specific scales used. The SIP holds some promise as a broad measure of functional status in PD patients.

Cognitive impairment and dementia in Parkinson's disease: a controlled study

The performance of 47 patients with Parkinson's disease on a battery of tests of cognition, motor function, disability and mood was compared with the performance of 47 healthy control subjects who were matched to the patients on the basis of age, sex and pre-morbid IQ. An increased prevalence of impairment over a range of cognitive functions was observed in the Parkinson's disease patients as compared with their matched controls. The differences between the Parkinson's disease patients and controls could not be accounted for by factors such as depressed mood, effects of medication or motor impairment. Our findings are discussed in relation to the methodology of previous studies in this area and to the need for a comprehensive clinico-pathological longitudinal study.

Effects of withdrawal of antiparkinson medication on gait and clinical score in the Parkinson patient

Objective testing of medication is needed in Parkinson's disease. Gait analysis and clinical evaluation were done before and after a 24-h withdrawal of Parkinson medication. Twelve patients with stable, mild to moderate idiopathic parkinsonism (Hoehn and Yahr 1-3; seven men and five women mean age 59.9 years, mean duration of disease 6 years) were tested with gait analysis walking in five different paces. Velocity of gait, stride length and stride frequency, as well as stride length at constant velocity were calculated. Regression coefficients for the relation between stride length and stride frequency were also calculated. Clinical scoring according to the Webster rating scale and Hoehn and Yahr were performed for each test. Clinical functional assessment with a specially designed rise and gait test, an arm cycle test and the wooden rods test were done. Evaluated clinical score increased significantly (p less than 0.05) using both clinical tests. Maximum gait velocity (p less than 0.01), stride length at max. velocity (p less than 0.01), and stride length at constant velocity (p less than 0.03) were significantly decreased without medication. Stride frequency did not change. In the functional assessment tests only performance on the arm cycle test (p less than 0.03) was less well performed without medication. There was correlation between clinical score, gait and clinical functional assessment. The methods used detected significant changes in variables of gait as well as clinical scoring and some of the clinical functional assessments when medication was withdrawn for a 24-h period. The methods were useful in evaluation of pharmacological treatment.

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.

Scales for rating motor impairment in Parkinson's disease: studies of reliability and convergent validity

Study 1 examined the reliability of the ratings assigned to the performance of five sign-and-symptom items drawn from tests of motor impairment in Parkinson's disease. Patients with Parkinson's disease of varying severity performed gait, rising from chair, and hand function items. Video recordings of these performances were rated by a large sample of experienced and inexperienced neurologists and by psychology undergraduates, using a four point scale. Inter-rater reliability was moderately high, being higher for gait than hand function items. Clinical experience proved to have no systematic effect on ratings or their reliability. The idiosyncrasy of particular performances was a major source of unreliable ratings. Study 2 examined the intercorrelation of several standard rating scales, comprised of sign-and-symptom items as well as activities of daily living. The correlation between scales was high, ranging from 0.70 to 0.83, despite considerable differences in item composition. Inter-item correlations showed that the internal cohesion of the tests was high, especially for the self-care scale. Regression analysis showed that the relationship between the scales could be efficiently captured by a small selection of test items, allowing the construction of a much briefer test.

Disability profiles and objective quantitative assessment in Parkinson's disease

A new technique for quick objective and quantitative determination of important aspects of the motor handicap in movement disorders is presented. A compound, but natural, test movement was used to find out if the degree of dysfunction in postural, locomotor and manual motor functions differed among the patients and if medication influenced these functions differently. After 12 h without medication, 16 patients with Parkinson's disease showed a movement time between 1.5 and 13.6 times that of an age-matched normal subject and a greater performance variability on repeated examination. In some patients the increase of test movement time was caused mainly by the locomotion component while in others the time for the postural or manual part of the movement was more markedly augmented. Thus, a specific motor disability profile was found for each patient and expressed in quantitative terms. The effects of l-dopa treatment were quantified in each patient.

Optimum symptomatic control of Parkinson's disease with dopaminergic therapy

This paper presents a review of the literature on the therapeutic action and the side effects of the two main dopaminergic agents: L-DOPA/decarboxylase inhibitor (L-DOPA/DI) and bromocriptine (Parlodel used either as monotherapy or in combination in patients with Parkinson's disease. The combination of L-DOPA/DI and bromocriptine gives the best therapeutic efficacy (49% improvement) in the total score (bradykinesia, rigidity and tremor). However, treatment by monotherapy or combination gives the same pattern of activity: greatest improvement in tremor, followed by rigidity and bradykinesia. Improvement observed in the short term is not sustained over longer periods of time for monotherapy with either drug. The short-term side effects are similar for each treatment, whereas long-term complications (dyskinesia, end-of-dose deterioration and on-off phenomenon) appear only when levodopa is used, alone (high incidence) or in combination with bromocriptine (low incidence). The overall optimum treatment is obtained with a combination of L-DOPA/DI and bromocriptine.

Parkinsonism--drug treatment: Part I

The purpose of this two-part review is to explain current drug treatment in part I and discuss investigational drug therapy and miscellaneous drugs in the management of parkinsonism in part II. The medical approach to this disease is still based on the imbalance between a deficiency of dopamine and a functional increase in acetylcholine. Anticholinergic agents are used to treat the tremors in the early stages of the disease.

Saccade responses to dopamine in human MPTP-induced parkinsonism

Depletion of dopamine content in the substantia nigra resulting from 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) toxicity produces parkinsonism. Management of 3 patients with MPTP-induced parkinsonism required drug holidays during which there was a state of dopamine depletion followed by dopamine replacement. We used this opportunity to study the effect of the selective loss of pars compacta dopaminergic cells on vertical and horizontal saccade (fast) eye movements. During the drug holidays, visually guided saccades were hypometric and had long latencies but retained a normal saccade velocity-amplitude relationship. Dopamine agonists or precursors improved the accuracy and reaction times of saccades in all directions, but not their velocity. Two of the three patients also had intermittent blepharospasm during dopamine depletion. During the episodes of blepharospasm, saccade responses became slow eye movements. MPTP causes a dopaminergic-responsive disorder of saccade initiation that is similar to idiopathic parkinsonism. The inhibition of voluntary eyelid opening during MPTP-induced blepharospasm further increases this impairment of fast eye movements and altered saccade velocity, presumably via the pars reticulata of the substantia nigra.

Depression in Parkinson disease: a disabling but neglected factor

20 depressed and 20 non depressed patients with Parkinson disease were rated for disability on the Northwestern University Disability Scale and for severity of the "typical" motor symptoms on the Columbia University Rating Scale and were assessed for mental deterioration. The severity of the "typical" symptoms was practically equivalent in the two groups but the depressed patients not only presented mild mental deterioration but were significantly more disabled (less independent) than the patients without depression. A significant correlation was found between severity of depression and degree of disability but not between severity of depression and severity of "typical" motor symptoms. Depression was diagnosed much later than the "typical" symptoms. Only 25% of the depressed parkinsonians had received tricyclic antidepressants, about 20% had been treated with dopamine-antagonist psychotropic drugs and some 50% had received no treatment at all against depression. Timely diagnosis and appropriate treatment of depression in parkinsonian patients limits the effects of a major disabling factor.