Tremor at onset. Predictor of cognitive and motor outcome in Parkinson's disease?

The Ventral Intermediate Nucleus Differently Modulates Subtype-Related Networks in Parkinson's Disease

Background: Posture instability gait difficulty-dominant (PIGD) and tremor-dominant (TD) are two subtypes of Parkinson's disease (PD). The thalamus is involved in the neural circuits of both subtypes. However, which subregion of the thalamus has an influence on the PD subtypes remains unclear. Objective: To explore the core subregion of the thalamus showing a significant influence on the PD subtypes and its directional interaction between the PD subtypes. Methods: A total of 79 PD patients (43 TD and 36 PIGD) and 31 normal controls (NC) were enrolled, and the gray matter volume and perfusion characteristics in the thalamus were compared between the three groups. The subregion of the thalamus with significantly different perfusion and volume among three groups was used as the seed of a Granger causality analysis (GCA) to compare the causal connectivity between different subtypes. Results: Perfusion with an increased gradient among the three groups (TD > PIGD > NC) in the bilateral ventral intermediate nucleus (Vim) was observed, which was positively correlated with the clinical tremor scores. The GCA revealed that TD patients had enhanced causal connectivity from the bilateral Vim to the bilateral paracentral gyrus, M1 and the cerebellum compared with the NC group, while the PIGD subtype revealed an increased causal connectivity from the bilateral Vim to the bilateral premotor cortex (preM) and putamen. Additionally, there were positive correlations between the tremor scores and a causal connectivity from the Vim to the cerebellum. The connectivity from the right Vim to the right preM and the right putamen was positively correlated with the PIGD scores. Conclusion: This multilevel analysis showed that the Vim had a significant influence on the PD subtypes and that it differentially mediated the TD and PIGD-related causal connectivity pattern in PD.

Lower levels of uric acid and striatal dopamine in non-tremor dominant Parkinson's disease subtype

Parkinson’s disease (PD) patients who present with tremor and maintain a predominance of tremor have a better prognosis. Similarly, PD patients with high levels of uric acid (UA), a natural neuroprotectant, have also a better disease course. Our aim was to investigate whether PD motor subtypes differ in their levels of UA, and if these differences correlate with the degree of dopamine transporter (DAT) availability. We included 75 PD patients from whom we collected information about their motor symptoms, DAT imaging and UA concentration levels. Based on the predominance of their motor symptoms, patients were classified into postural instability and gait disorder (PIGD, n = 36), intermediate (I, n = 22), and tremor-dominant (TD, n = 17) subtypes. The levels of UA and striatal DAT were compared across subtypes and the correlation between these two measures was also explored. We found that PIGD patients had lower levels of UA (3.7 vs 4.5 vs 5.3 mg/dL; P<0.001) and striatal DAT than patients with an intermediate or TD phenotype. Furthermore, UA levels significantly correlated with the levels of striatal DAT. We also observed that some PIGD (25%) and I (45%) patients had a predominance of tremor at disease onset. We speculate that UA might be involved in the maintenance of the less damaging TD phenotype and thus also in the conversion from TD to PIGD. Low levels of this natural antioxidant could lead to a major neuronal damage and therefore influence the conversion to a more severe motor phenotype.

The Profile of Long-term Parkinson's Disease Survivors with 20 Years of Disease Duration and Beyond

BACKGROUND

Parkinson's disease (PD) patients with 20 years or more survival (PD-20) are not well characterized.

OBJECTIVE

To evaluate PD-20 patient characteristics and identify areas for improvement of their health care.

METHODS

The international, multicenter National Parkinson's Foundation Quality Improvement Initiative (NPF-QII) study database was queried to identify PD-20 subjects. Demographic and clinical data were analyzed.

RESULTS

We identified 187 PD-20 subjects (55% men) representing 4% (187/4,619) of all NPF-QII participants. Subjects were mean age 69.5 years; mean age at PD onset was 44.0 years. The majority (75% ) had 20-25 years of PD duration, the longest duration being 49 years. They were median Hoehn and Yahr stage 3, and 75% had motor fluctuations. Half (54% ) reported exercising. The majority (89% ) were living at home and required a caregiver (88% ). They were mildly cognitively impaired for age (Montreal Cognitive Assessment estimate 22.6±3.7), with most deficits in verbal fluency and delayed recall. Quality of life (Parkinson's Disease Quality of Life Questionnaire index 36±15% ) was mild to moderately impaired, with most impairment in mobility and activities of daily living. Caregiver strain measured by the Multidimensional Caregiver Strain Index (27±16% ), recorded highest subscores in social constraint. PD-20 subjects aged <70 years versus ≥70 only differed significantly by worse cognition (P <  0.0001).

CONCLUSIONS

PD-20 subjects reflect an elite group of PD survivors with early-onset disease and relatively mild cognitive disability despite long disease duration. Interventions for caregivers, mobility, and activities of daily living are areas that could improve caregiver burden and patient quality of life.

The impact of nonmotor symptoms on quality of life in patients with Parkinson's disease in Taiwan

PURPOSE

The nonmotor symptoms (NMS) of Parkinson's disease (PD) are important factors for quality of life (QoL). Few studies on NMS have been conducted in Asian PD patients. Additionally, effects of anti-PD drugs on risk of NMS are still controversial. We therefore conducted this hospital-based cross-sectional study to examine the clinical factors, including concomitant anti-PD medication use, on the occurrence of NMS and QoL in Taiwanese PD patients.

PATIENTS AND METHODS

PD patients who received long-term follow-up in the movement disorders clinics were enrolled and received NMS questionnaire (NMSQuest) and the 39-item Parkinson's Disease Questionnaire (PDQ-39). Spearman's rank correlation coefficient was checked for the correlation between clinical factors and NMSQT/PDQSI. Multiple linear regressions were applied to assess the influence of clinical factors on NMSQT/PDQSI.

RESULTS

A total of 210 PD patients (mean age 66.1±9.86 years, Hoehn and Yahr stage 2.2±0.9) were included in this study. Up to 98% of patients reported at least one symptom of NMS. The most prevalent symptom was urinary complaints (56%), followed by memory/apathy (30%) and depression/anxiety (28%). The correlation between NMSQT and PDQSI was strong (r s=0.667), especially the item of depression/anxiety (r s=0.607). The regression model for NMSQT indicated that disease duration and severity, but not pharmacological therapy, were major predictors of NMS.

CONCLUSION

Our data indicated a high prevalence rate of NMS in PD patients. Among symptoms of NMS, depression and anxiety had the greatest impact on QoL. Concomitant anti-PD medication use did not affect the occurrence of NMS and QoL.

Examining the motor phenotype of patients with both essential tremor and Parkinson's disease

Background

The subset of patients with essential tremor (ET) that develops Parkinson's disease (PD) has not been fully clinically characterized.

Methods

Motor features were retrospectively reviewed in 18 ET patients who developed PD (ET→PD), 20 ET and 30 PD patients with similar ages and disease durations.

Results

Fewer ET→PD than ET patients had widespread postural and/or action tremor (2/17 [11.8%] vs. 11/17 [64.7%]; p = 0.001) and marginally fewer had cerebellar signs (1/15 [6.7%] vs. 6/18 [33.3%], p = 0.06). ET→PD patients required fewer ET medications than did their counterparts with ET (p = 0.001). ET→PD patients and PD patients did not differ in UPDRS, Hoehn and Yahr, or Schwab and England scores (each p≥0.14).

Discussion

ET patients who develop PD may have distinct pre-PD motor features compared to their counterparts with ET who do not develop co-existing PD. Prospective studies are needed to evaluate the predictive value of these clinical features for the emergence of PD.

A double-blind, delayed-start trial of rasagiline in Parkinson's disease (the ADAGIO study): prespecified and post-hoc analyses of the need for additional therapies, changes in UPDRS scores, and non-motor outcomes

BACKGROUND

The ADAGIO study investigated whether rasagiline has disease-modifying effects in Parkinson's disease. Rasagiline 1 mg per day, but not 2 mg per day, was shown to be efficacious in the primary analysis. Here, we report additional secondary and post-hoc analyses of the ADAGIO study.

METHODS

ADAGIO was a placebo-controlled, double-blind, multicentre, delayed-start study, in which 1176 patients with untreated early Parkinson's disease were randomly assigned to receive rasagiline 1 mg or 2 mg per day for 72 weeks (early-start groups) or placebo for 36 weeks followed by rasagiline 1 mg or 2 mg per day for 36 weeks (delayed-start groups). We assessed the need for additional antiparkinsonian therapy and changes in non-motor experiences of daily living and fatigue scales (prespecified outcomes) and changes in unified Parkinson's disease rating scale (UPDRS) scores and subscores in placebo and active groups (post-hoc outcomes). The ADAGIO study is registered with ClinicalTrials.gov, number NCT00256204.

FINDINGS

The need for additional antiparkinsonian therapy was reduced with rasagiline 1 mg (25 of 288 [9%] patients) and 2 mg (26 of 293 [9%]) versus placebo (108 of 593 [18%]; odds ratio for 1 mg rasagiline vs placebo 0·41, 95% CI 0·25-0·65, p=0·0002; 2 mg rasagiline vs placebo 0·41, 0·26-0·64, p=0·0001). At week 36, both doses significantly improved UPDRS motor subscores compared with placebo (1 mg rasagiline mean difference -1·88 [SE 0·35]; 2 mg rasagiline -2·18 [0·35]; both p<0·0001) and activities of daily living subscores (ADL; 1 mg rasagiline -0·86 [0·18]; 2 mg rasagiline -0·88 [0·18]; both p<0·0001), and 1 mg rasagiline significantly improved UPDRS mentation subscore (-0·22 [0·08]; p=0·004). At week 72, the only significant difference between early-start and delayed-start groups was for ADL subscore with the 1 mg dose (-0·62 [0·29]; p=0·035). When assessed for the effect on non-motor symptoms at week 36, both doses showed benefits on the Parkinson fatigue scale versus placebo (1 mg rasagiline mean difference -0·14 [SE 0·05], p=0·0032; 2 mg rasagiline -0·19 [0·05], p<0·0001), and the 1 mg dose showed benefits on the scale for non-motor experiences of daily living compared with placebo (mean difference -0·33 [0·17]; p=0·049). The rate of progression of total UPDRS score for patients in the placebo group was 4·3 points [SE 0·3] over 36 weeks, with extrapolation to about 6 units per year. In the placebo group, patients with the lowest quartile of baseline UPDRS scores (≤14; n=160) progressed more slowly than did those with highest scores (>25·5; n=145; mean difference -3·46 [SE 0·77]; p<0·0001).

INTERPRETATION

These findings show that rasagiline delayed the need for symptomatic antiparkinsonian drugs and emphasise the contribution of the UPDRS ADL in the response of the rasagiline 1 mg per day early-start versus delayed-start group. The rate of UPDRS deterioration was less than was anticipated from previous studies and correlated with baseline severity. Understanding of the pattern of UPDRS deterioration is essential to assess disease modification.

FUNDING

Teva Pharmaceutical Industries and H Lundbeck A/S.

The effect of onset age on the clinical features of Parkinson's disease

Many clinicians view age at onset as an important determinant of clinical phenotype in Parkinson's disease (PD) and this has been reinforced by the identification of Mendelian genes that account for some cases of younger onset PD. A systematic review of OVID Medline for articles relevant to the relationship between clinical features and age at onset in PD published in English between 1950-2007 was performed. There are very few prospective community based studies which focus on the relationship between age at onset and the features of PD and a variety of case definitions are used in the literature. Most studies of young onset PD are based on specialist clinic referral series. The available evidence suggests that PD patients with a younger age at onset have: (i) a slower disease progression, (ii) an increased rate of dystonia at onset and during treatment, (iii) a lower rate of dementia and (iv) an increased rate of dyskinesias in response to L-DOPA treatment. The majority of the available studies do not report patient genotype data, but it is probably that the clinical heterogeneity of PD will be further refined with detailed clinico-genetic studies.

Side and type of motor symptom influence cognition in Parkinson's disease

It is well known that many patients with Parkinson's disease experience neuropsychological decline. However, the nature and extent of mental status change varies widely, with some patients showing mild or no cognitive impairments and others exhibiting frank dementia. Research has shown that several clinical disease parameters may differentially correlate with patterns of neuropsychological dysfunction. The present study examined side and type of motor symptom at disease onset and their relationship to cognition in idiopathic Parkinson's disease (PD). We identified 58 patients who initially presented with one of the following symptom profiles: right-side tremor onset (RSO-T; n = 15), right-side bradykinesia/rigidity onset (n = 12), left-side tremor onset (n = 19), and left-side bradykinesia/rigidity onset (n = 12). There were no differences between groups in disease duration, overall mental status, education, or depression severity. We administered a battery of neuropsychological measures to the four PD subgroups and a group of matched control subjects (n = 40). MANCOVAs controlling for age revealed patients with RSO-T performed significantly better than the other three PD subgroups across the entire neuropsychological battery. Further, the RSO-T subgroup performed comparably to controls. In contrast, the other three PD subgroups showed widespread cognitive deficits. These findings suggest an intricate relationship between motor symptom and side of disease onset and it is the combination of these factors that may influence the disease course and extent of cognitive deterioration. Furthermore, patients who develop tremor on the right side of their body represent a distinct subgroup of PD patients who exhibit relative sparing of cognitive function.

Extrapyramidal features in Parkinson's disease with and without dementia and dementia with Lewy bodies: A cross-sectional comparative study

Risk factors predicting an increased risk of dementia in Parkinson's disease (PD) are not fully established. The dementia associated with PD (PDD) closely resembles dementia with Lewy bodies (DLB). Based upon a high frequency of non-dopaminergic mediated clinical features in DLB, we predicted that a motor subtype comprising postural instability and balance problems would be more common in PDD. We examined extrapyramidal, cognitive, and affective features in 38 PD, 43 PDD, and 26 DLB patients in a cross-sectional study design. Motor subtype was subdivided into postural-instability gait difficulty (PIGD) or tremor (TD) dominant. The PIGD-subtype was more common in PDD (88% of cases) and DLB (69% of cases) groups compared with the PD group (38% of cases), in which TD and PIGD sub-types were more equally represented (P < 0.001). Although the mean depression scores overall were modest, PDD patients scored significantly higher than PD, but not DLB patients (Cornell; P = 0.006, and Geriatric Depression scale, GDS-15; P = 0.001), while within the PD group, those patients with a PIGD subtype had greater depression scores than the TD subtype (GDS-15; P < 0.05). We conclude that non-dopaminergic motor features are frequent in PDD. Neurodegeneration within the cholinergic system is likely to mediate many of these motor problems, as well as playing a significant role in determining the neuropsychiatric symptomatology of both PDD and DLB.

Impairment of post-movement beta synchronisation in parkinson's disease is related to laterality of tremor

OBJECTIVE

Post-movement beta synchronisation (PMBS) is a physiological indicator of the activity of movement related neural networks. To investigate the pathophysiology of this phenomenon, we examined its characteristics in patients with unilateral tremor-dominant Parkinson's disease (PD).

METHODS

Movement duration and PMBS was measured after self-paced movement of the thumb at movement-reactive beta frequencies, over the supplementary motor area in 10 PD patients and 8 control subjects.

RESULTS

Movement duration in PD patients was longer than in controls. In left hand tremor patients, movement of the left hand was significantly longer compared to the right hand. When PD patients moved their non-affected hand, similarly to the controls, PMBS was higher contralateral to the movement. After movement of the tremulous hand, the contralateral PMBS decreased significantly and the contralateral preponderance disappeared. In the same hemisphere, PMBS was higher after contralateral to the non-affected hand movement, than after ipsilateral to the tremulous hand after movement.

CONCLUSIONS

PMBS in PD is affected by the activity of tremor related neural networks, suggesting that both cortical and subcortical sources are responsible for its generation. Examination of PMBS in various neurological diseases might provide further data on its physiological significance.

Medical services utilization and prognosis in Parkinson disease: a population-based study

OBJECTIVES

To investigate prognostic outcomes and utilization of medical services by patients with Parkinson disease (PD) and to identify predictors of such use.

PATIENTS AND METHODS

Using the medical records linkage system of the Rochester Epidemiology Project, we identified an incidence cohort of 89 PD cases (Olmsted County, Minnesota, 1979-1988) and a reference group of 89 subjects without PD of the same age and sex and from the same population. Both patients with PD and reference subjects were followed up historically by medical record review from onset of PD (or index year) through death, last contact with the system, or end of study.

RESULTS

Patients with PD had significantly more physician consultations per year (median, 7.9 vs 5.9; P=.001) and more emergency department visits per year (median, 0.6 vs 0.4; P=.05) than did reference subjects. Response to dopaminergic medications and higher education predicted more physician consultations among patients. The PD patients used neuroleptics and antidepressants significantly more frequently than reference subjects. The risk of nursing home placement was significantly increased for PD patients compared with reference subjects (relative risk, 6.7; 95% confidence interval, 3.7-12.1; P<.001). Poor response to dopaminergic medications, lower education level, older age at onset of PD, and dementia predicted a shorter time between onset and nursing home placement among PD patients. Survival was significantly reduced in PD patients compared with reference subjects (relative risk, 2.2; 95% confidence interval, 1.4-3.4; P<.001). Good response to dopaminergic medications, higher education, younger age at onset of PD, and absence of dementia predicted better survival among PD patients.

CONCLUSIONS

Patients with PD used outpatient and nursing home services more often than subjects without PD. Patients with PD also experienced a reduced survival time. Demographic and clinical characteristics influenced utilization patterns and outcomes.

Parkinson's disease subtypes: clinical classification and ventricular cerebrospinal fluid analysis

The current study presents preliminary data regarding the development and validation of a rating system designed to classify PD patients into clinical subgroups. Using portions of the Unified Parkinson's Disease Rating Scale, a ratio value was derived, yielding three patient subtypes: a tremor-dominant group (T), an akinetic-rigid group (AR), and a mixed group (MX). Validation of the schema was conducted by grouping PD surgical candidates into specific disease subtypes and evaluating differences in neurotransmitter profiles among disease subtypes and non-PD neurological controls. High pressure liquid chromatography analysis of ventricular cerebrospinal fluid indicated 5-hydroxyindoleacetic acid was significantly lower in the AR and MX groups compared to non-PD controls; whereas, glycine was significantly higher in the AR group compared to the T, MX, and control groups. The results suggest that an operational approach can be utilized to differentiate between PD subtypes with distinct neurochemical profiles.

A data-driven approach to the study of heterogeneity in idiopathic Parkinson's disease: identification of three distinct subtypes

Idiopathic Parkinson's disease (IPD) has been subclassified on the basis of predominant motor symptomatology, age at disease onset, depressive affect, and cognitive performance. However, subgroups are usually arbitrarily defined and not reliably based on qualitatively distinct neuropathology. We explored heterogeneity in IPD in a data-driven manner using comprehensive demographic, motor, mood, and cognitive information collected from 176 patients with IPD. Cluster analysis revealed three subgroups of patients at a disease duration of 5.6 years and two subgroups at 13.4 years. The subgroups may represent the clinical progression of three distinct subtypes of IPD. The "motor only" subtype was characterized by motor symptom progression in the absence of intellectual impairment. Equivalent motor symptom progression was shown by the "motor and cognitive" subtype which was accompanied by executive function deficits progressing to global cognitive impairment. The "rapid progression" subtype was characterized by an older age at disease onset and rapidly progressive motor and cognitive disability. There was no relationship between the motor and cognitive symptoms in any subtype of IPD. We conclude that the clinical heterogeneity of IPD is governed by distinct neuropathologic processes with independent etiologic influences.

Behavioral relaxation training for tremor disorders in older adults

Two adult men, aged 86 and 63, with essential tremor and Parkinson's-disease-related tremor, respectively, were provided Behavioral Relaxation Training in reclined and upright seated positions. Multiple measures were recorded, including the Behavioral Relaxation Scale (BRS), clinical and self-rated tremor severity, informant ratings, ratings of disability in activities of daily living (ADL), and forearm EMG. Results showed increased relaxation skills on the BRS, with reductions in EMG, tremor ratings, and some ADL disabilities. Upright BRS scores did not change during reclined training, but improved rapidly during upright training. The second man was found to suffer from dyskinesia when he relaxed during baseline, which declined markedly during training. A two-week follow-up indicated that most improvements were maintained by both men. Statistical analyses of data for each man showed significant changes. These results suggest that relaxation may be useful in the treatment of idiopathic and pathologic tremor disorders in older adults.