Treatment of Parkinson's disease

Does Impaired Plantar Cutaneous Vibration Perception Contribute to Axial Motor Symptoms in Parkinson's Disease? Effects of Medication and Subthalamic Nucleus Deep Brain Stimulation

OBJECTIVE

To investigate whether impaired plantar cutaneous vibration perception contributes to axial motor symptoms in Parkinson's disease (PD) and whether anti-parkinsonian medication and subthalamic nucleus deep brain stimulation (STN-DBS) show different effects.

METHODS

Three groups were evaluated: PD patients in the medication "on" state (PD-MED), PD patients in the medication "on" state and additionally "on" STN-DBS (PD-MED-DBS), as well as healthy subjects (HS) as reference. Motor performance was analyzed using a pressure distribution platform. Plantar cutaneous vibration perception thresholds (VPT) were investigated using a customized vibration exciter at 30 Hz.

RESULTS

Motor performance of PD-MED and PD-MED-DBS was characterized by greater postural sway, smaller limits of stability ranges, and slower gait due to shorter strides, fewer steps per minute, and broader stride widths compared to HS. Comparing patient groups, PD-MED-DBS showed better overall motor performance than PD-MED, particularly for the functional limits of stability and gait. VPTs were significantly higher for PD-MED compared to those of HS, which suggests impaired plantar cutaneous vibration perception in PD. However, PD-MED-DBS showed less impaired cutaneous vibration perception than PD-MED.

CONCLUSIONS

PD patients suffer from poor motor performance compared to healthy subjects. Anti-parkinsonian medication in tandem with STN-DBS seems to be superior for normalizing axial motor symptoms compared to medication alone. Plantar cutaneous vibration perception is impaired in PD patients, whereas anti-parkinsonian medication together with STN-DBS is superior for normalizing tactile cutaneous perception compared to medication alone. Consequently, based on our results and the findings of the literature, impaired plantar cutaneous vibration perception might contribute to axial motor symptoms in PD.

Anticipatory Postural Adjustments and Compensatory Postural Responses to Multidirectional Perturbations-Effects of Medication and Subthalamic Nucleus Deep Brain Stimulation in Parkinson's Disease

BACKGROUND

Postural instability is one of the most restricting motor symptoms for patients with Parkinson's disease (PD). While medication therapy only shows minor effects, it is still unclear whether medication in conjunction with deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves postural stability. Hence, the aim of this study was to investigate whether PD patients treated with medication in conjunction with STN-DBS have superior postural control compared to patients treated with medication alone.

METHODS

Three study groups were tested: PD patients on medication (PD-MED), PD patients on medication and on STN-DBS (PD-MED-DBS), and healthy elderly subjects (HS) as a reference. Postural performance, including anticipatory postural adjustments (APA) prior to perturbation onset and compensatory postural responses (CPR) following multidirectional horizontal perturbations, was analyzed using force plate and electromyography data.

RESULTS

Regardless of the treatment condition, both patient groups showed inadequate APA and CPR with early and pronounced antagonistic muscle co-contractions compared to healthy elderly subjects. Comparing the treatment conditions, study group PD-MED-DBS only showed minor advantages over group PD-MED. In particular, group PD-MED-DBS showed faster postural reflexes and tended to have more physiological co-contraction ratios.

CONCLUSION

medication in conjunction with STN-DBS may have positive effects on the timing and amplitude of postural control.

Boxing with Parkinson's Disease: findings from a qualitative study using self-determination theory

PURPOSE

Adults with Parkinson's disease (PD) experience debilitating symptoms that may be mitigated by boxing. Yet, attrition from boxing programs is problematic. Understanding whether PD-specific boxing programs can enhance motivation to remain physically active is important. This study investigated adults' experiences within a PD-specific boxing program and explored their perspectives on how the program has influenced physical activity motivational processes using a self-determination theory (SDT) lens. Methods: Nine adults with PD who took part in the Boxing 4 Health PD-specific boxing program completed face-to-face, semi-structured interviews. Data were analyzed using a hybrid approach of inductive and deductive thematic analysis. Results: The analysis yielded five themes: (1) I made an informed decision to participate and it feels good, (2) Boxing helps me stay active and keep moving, (3) To keep me going, the boxing program needs to have variety and allow for input, (4) A program that can be adapted to me is important, and (5) The instructor and the group facilitate my continued participation in the program. Conclusion: Providing participants with adapted exercises, varied sessions, and opportunities to provide input in a group-based PD-specific boxing program may be conducive to enhancing motivation for physical activity. Further, SDT may be a useful theoretical framework for developing and evaluating PD-specific programs.IMPLICATIONS FOR REHABILITATIONAdults with Parkinson's disease (PD) have many reasons for not engaging in physical activity, including a lack of motivation.A group-based PD-specific boxing program may be conducive to increasing motivation for physical activity.Professionals should consider: (1) educating adults with PD on the benefits of boxing, (2) offering group-based PD-specific boxing programs that are adaptable, varied, and open to input, and (3) fostering social support and networking opportunities within such programs.

Pioglitazone use and Parkinson's disease: a retrospective cohort study in Taiwan

OBJECTIVES

Many researchers have expected pioglitazone to serve as an effective neuroprotective agent against Parkinson's disease (PD). Therefore, we conducted this cohort study to investigate the association between pioglitazone use and PD by using a large Asian population-based dataset in Taiwan.

DESIGN

Retrospective cohort study.

SETTING

Taiwan.

PARTICIPANTS

7906 patients with diabetes who had received pioglitazone were defined as the study cohort, and 7906 matched patients with diabetes who had not received pioglitazone were defined as the comparison cohort.

PRIMARY AND SECONDARY OUTCOME MEASURES

We tracked each patient individually over a 5-year follow-up period to identify those diagnosed as having PD during this period. We performed Cox proportional hazard regression analyses to evaluate the HRs for PD between the study and comparison cohorts.

RESULTS

The findings indicated that among the sampled patients, PD occurred in 257 (1.63%): 119 (1.51%) pioglitazone users and 138 (1.75%) non-users. The adjusted HR for PD within the follow-up period was 0.90 (95% CI: 0.68 to 1.18) in the patients who had received pioglitazone compared with the matched patients who had not received pioglitazone. Moreover, this study revealed that pioglitazone use was not associated with PD incidence in men (HR: 1.06, 95% CI: 0.71 to 1.59) or women (HR: 0.84, 95% CI: 0.61 to 1.15).

CONCLUSIONS

This study did not find the relationship between pioglitazone use and PD incidence, regardless of sex, among an Asian population of patients with diabetes.

Group Education with Personal Rehabilitation for Idiopathic Parkinson's Disease

Objective:

To evaluate the effect of a group education program with personal rehabilitation for idiopathic Parkinson's disease (IPD).

Methods:

A single-blind, randomized, controlled clinical trial, with a pre-test/post-test quasi-experimental design. Fortyfour stable, non-demented patients with IPD were randomly assigned to an intervention group (n=23) and control group (n=21). Three group lectures on health education specific to IPD were delivered to the intervention group. The theme of lectures was “Not a lonely journey, as your friend, we—experts specializing in IPD— would love to join with you.” Three domains of the management of IPD were mentioned: “How to manage your routine Meal, Moving and Mood after suffering from IPD” Each lecture was scheduled for 45 minutes (excluding breaks), and designed as an interactive dialogue rather than a traditional lecture. To strengthen the impact of the lectures, relevant information was published on a website: http://www.parkinsonism.cn/. Following the group lecture, individualized and tailored rehabilitation made up of 24 half-hour sessions over eight weeks were provided for the intervention group.

Results:

The program ran smoothly and IPD patients were satisfied with this program. After only eight weeks, the health-related quality of life (HR-QOL) in the intervention group improved significantly (p<0.001). Patients and their caregivers in this group also reported their mood elevations following the program.

Conclusion:

Group education combined with personal rehabilitation program appears to be a beneficial and practical intervention, not only complementing the medical treatment for IPD patients but also meeting the growing demand for long-term care.

Nanoprobing of α-synuclein misfolding and aggregation with atomic force microscopy

Atomic force microscopy (AFM) force spectroscopy is a technique with broad nanomedical applications, widely used for the characterization of molecular interactions on the nanoscale. Here we test this technique to evaluate compounds for influencing the protein aggregation process. The results demonstrate that Zn(2+) or Al(3+) cations bring about a dramatic increase of α-synuclein interactions in unfavorable conditions for α-synuclein misfolding (neutral pH). We did not observe the effect of dopamine at favorable conditions for α-synuclein misfolding (acidic pH). We also found that electrostatic interactions do not play a significant role at acidic pH. These findings are generally in line with previous studies by various techniques. The high sensitivity of AFM force spectroscopy as well as its ability to test compounds for the same experimental system makes AFM an efficient nanotool for rapid analysis of compounds inhibiting early protein aggregation studies and quantitative selection of potential therapeutics for neurodegenerative diseases.

FROM THE CLINICAL EDITOR

Atomic force microscopy is used to interrogate the influence of cations and α-synuclein on the protein aggregation process. The report illustrates an application of AFM to unravel the potential of novel therapeutics on early protein aggregation intrinsic in neurodegenerative diseases.

Spectroscopy of human plasma for diagnosis of idiopathic Parkinson’s disease

Background: No established chemical biomarkers of idiopathic Parkinson’s disease (PD) currently exist. Augmented oxidative stress (OS) has been implicated in both neural and peripheral PD tissues. Methods: In this study, Raman scattering and near-infrared spectroscopy were used to detect and quantify oxidative substrate modifications in blood plasma samples from PD and normal elderly control (NEC) subjects. Results:Hypothesis-driven preselection of OS-sensitive bandwidths distinguished PD from NEC subjects with approximately 75% sensitivity and specificity using both complementary spectroscopic techniques. Conclusion: Biospectroscopy of plasma may provide a rapid, minimally invasive and inexpensive chemical biomarker of idiopathic PD.

Calcitriol protection against dopamine loss induced by intracerebroventricular administration of 6-hydroxydopamine

Calcitriol has been implicated as an agent that has neuroprotective effects in various animal models of diseases, possibly by upregulating glial cell line-derived neurotrophic factor (GDNF). The present study examined the neuroprotective effects of calcitriol in a model of early Parkinson's disease. Rats were treated daily with calcitriol or saline for 7 days before an intraventricular injection of 6-hydroxydopamine (6-OHDA), and then for 1 day or daily for 3(1/2) to 4 weeks after lesioning. Evoked overflow and tissue content of dopamine (DA) were determined 3(1/2) to 4 weeks post lesion. The 8-day calcitriol treatment did not attenuate 6-OHDA-induced decreases in evoked overflow of DA, nor did it protect against 6-OHDA-induced reductions in tissue levels of DA in the striatum or substantia nigra. However, the long-term calcitriol treatment did significantly increase evoked overflow of DA, as well as the amount of DA in the striatum, compared to saline treated animals. GDNF was significantly increased in the substantia nigra, but not in the striatum, of non-lesioned, calcitriol treated rats. These results suggest that long-term treatment with calcitriol can provide partial protection for dopaminergic neurons against the effects of intraventricularly administered 6-OHDA.

Gene-environment interactions in sporadic Parkinson's disease

Much has been learned in recent years about the genetics of familial Parkinson's disease. However, far less is known about those malfunctioning genes which contribute to the emergence and/or progression of the vast majority of cases, the 'sporadic Parkinson's disease', which is the focus of our current review. Drastic differences in the reported prevalence of Parkinson's disease in different continents and countries suggest ethnic and/or environmental-associated multigenic contributions to this disease. Numerous association studies showing variable involvement of multiple tested genes in these distinct locations support this notion. Also, variable increases in the risk of Parkinson's disease due to exposure to agricultural insecticides indicate complex gene-environment interactions, especially when genes involved in protection from oxidative stress are explored. Further consideration of the brain regions damaged in Parkinson's disease points at the age-vulnerable cholinergic-dopaminergic balance as being involved in the emergence of sporadic Parkinson's disease in general and in the exposure-induced risks in particular. More specifically, the chromosome 7 ACHE/PON1 locus emerges as a key region controlling this sensitive balance, and animal model experiments are compatible with this concept. Future progress in the understanding of the genetics of sporadic Parkinson's disease depends on globally coordinated, multileveled studies of gene-environment interactions.

Cardiovascular and electrocardiographic effects of the dopamine receptor agonists ropinirole, apomorphine, and PNU-142774E in conscious beagle dogs

To confirm recent in vitro findings, we examined the cardiovascular and electrocardiographic (ECG) effects of the dopamine receptor agonists ropinirole, apomorphine, and PNU-142774E in conscious dogs. Intravenous (i.v.) infusions of ropinirole totaling 20 microg/kg maximally reduced mean arterial pressure (MAP; -16 mm Hg) and the ECG PR interval (-13 milliseconds) and increased heart rate (HR; +29 b/min) and QTc length (+33 ms) at a peak plasma drug concentration (p[drug]) of 3.5 ng/ml. I.V. PNU-142774E was better tolerated through 66 microg/kg and a maximal p[drug] of 5.9 ng/ml with negligible cardiovascular changes and mild QTc reduction (13 ms). Apomorphine (25 microg/kg i.v.) was intermediate to ropinirole and PNU-142774E for emesis and peak changes in MAP (-6 mm Hg), HR (+24 b/min), and QTc (+15 milliseconds) at a mean p[drug] of 3.4 ng/ml. By comparison, the class III antiarrhythmic trecetilide (2.0 mg/kg bolus) increased QTc (+58 ms) without affecting mean arterial pressure or heart rate. This study establishes that in conscious dogs, the selective dopamine receptor agonist PNU-142774E has fewer cardiovascular and emetic effects than ropinirole and apomorphine and supports prior in vitro findings that ropinirole and apomorphine but not the PNU-142774E imidazoquinolin analog sumanirole reduces the delayed rectifier current in HERG transfected cells.

FDG PET in the differential diagnosis of parkinsonian disorders

The differential diagnosis of parkinsonian disorders can be challenging, especially early in the disease course. PET imaging with [(18)F]-fluorodeoxyglucose (FDG) has been used to identify characteristic patterns of regional glucose metabolism in patient cohorts with idiopathic Parkinson's disease (PD), as well as variant forms of parkinsonism such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBGD). In this study, we assessed the utility of FDG PET in the differential diagnosis of individual patients with clinical parkinsonism. 135 parkinsonian patients were referred for FDG PET to determine whether their diagnosis could be made accurately based upon their scans. Imaging-based diagnosis was obtained by visual assessment of the individual scans and also by computer-assisted interpretation. The results were compared with 2-year follow-up clinical assessments made by independent movement disorders specialists who were blinded to the original PET findings. We found that blinded computer assessment agreed with clinical diagnosis in 92.4% of all subjects (97.7% early PD, 91.6% late PD, 96% MSA, 85% PSP, 90.1% CBGD, 86.5% healthy control subjects). Concordance of visual inspection with clinical diagnosis was achieved in 85.4% of the patients scanned (88.4% early PD, 97.2% late PD, 76% MSA, 60% PSP, 90.9% CBGD, 90.9% healthy control subjects). This study demonstrates that FDG PET performed at the time of initial referral for parkinsonism accurately predicted the clinical diagnosis of individual patients made at subsequent follow-up. Computer-assisted methodologies may be particularly helpful in situations where experienced readers of FDG PET images are not readily available.