Parkinson's disease: medical and surgical treatment

Do we really improve life quality after total knee arthroplasty in patients with Parkinson's disease?

INTRODUCTION

The knee in Parkinson's disease (PD) patients is a problematic joint due to pain, stiffness and gait instability. The aim of this study is to evaluate the functional outcome and degree of pain relief achieved after total knee arthroplasty (TKA) in PD patients.

MATERIALS AND METHODS

This is a retrospective review of 26 PD patients (32 knees) with osteoarthritis who underwent a TKA between 1994 and 2013. Comorbidities, anesthetic procedures and complications were recorded. Patient functional status was assessed with the Knee Society Function Score (KFS) and the Knee Society Score (KSS). PD stage was classified with the Hoehn and Yahr Scale.

RESULTS

The mean follow-up was 3.5 years (range 2-9). The mean age was 71 years (range 61-83) with a mean time since PD diagnosis of 11.8 years (range 4-24). PD severity on the Hoehn and Yahr Scale was 1.5 points before surgery and 2 points postoperatively. Pain on the visual analogic scale improved from 8 points preoperatively to 5 points at 1-year follow-up; function improved from 32 (range 20-45) to 71 (range 50-81) and from 34 (range 28-52) to 59 (range 25-76) on the KSS and KFS, respectively. The mean postoperative hospital stay was 9.8 days (range 5-21). Confusion and flexion contracture were the most frequent perioperative complications.

CONCLUSION

TKA successfully provided pain relief in PD patients. However, the functional outcome is related to disease progression and, therefore, variable. Perioperative complications are difficult to avoid and manage.

A non-linear deterministic model of action selection in the basal ganglia to simulate motor fluctuations in Parkinson's disease

Motor fluctuations and dyskinesias are severe complications of Parkinson's disease (PD), especially evident at its advanced stage, under long-term levodopa therapy. Despite their strong clinical prevalence, the neural origin of these motor symptoms is still a subject of intense debate. In this work, a non-linear deterministic neurocomputational model of the basal ganglia (BG), inspired by biology, is used to provide more insights into possible neural mechanisms at the basis of motor complications in PD. In particular, the model is used to simulate the finger tapping task. The model describes the main neural pathways involved in the BG to select actions [the direct or Go, the indirect or NoGo, and the hyperdirect pathways via the action of the sub-thalamic nucleus (STN)]. A sensitivity analysis is performed on some crucial model parameters (the dopamine level, the strength of the STN mechanism, and the strength of competition among different actions in the motor cortex) at different levels of synapses, reflecting major or minor motor training. Depending on model parameters, results show that the model can reproduce a variety of clinically relevant motor patterns, including normokinesia, bradykinesia, several attempts before movement, freezing, repetition, and also irregular fluctuations. Motor symptoms are, especially, evident at low or high dopamine levels, with excessive strength of the STN and with weak competition among alternative actions. Moreover, these symptoms worsen if the synapses are subject to insufficient learning. The model may help improve the comprehension of motor complications in PD and, ultimately, may contribute to the treatment design.

Comparison of the structure, function and autophagic maintenance of mitochondria in nigrostriatal and tuberoinfundibular dopamine neurons

A pathological hallmark of Parkinson׳s disease (PD) is progressive degeneration of nigrostriatal dopamine (NSDA) neurons, which underlies the motor symptoms of PD. While there is severe loss of midbrain NSDA neurons, tuberoinfundibular (TI) DA neurons in the mediobasal hypothalamus (MBH) remain intact. In the present study, confocal microscopic analysis revealed that mitochondrial content and numbers of mitophagosomes were lower in NSDA neuronal cell bodies in the substantia nigra pars compacta (SNpc) compared to TIDA neuronal cell bodies in the arcuate nucleus (ARC) of C57BL/6J male mice. Mitochondrial respiration, mass, membrane potential and morphology were determined using bioenergetic, flow cytometric and transmission electron microscopic analyses of synaptosomes isolated from discrete brain regions containing axon terminals of NSDA and TIDA neurons. Maximum and spare respiratory capacities, and mitochondrial mass were lower in synaptosomal mitochondria derived from the striatum (ST) as compared with the MBH, which correlated with lower numbers of mitochondria per synaptosome in these brain regions. In contrast, there was no regional difference in mitochondrial basal, maximum or spare respirations following inhibition of Complex I activity with rotenone. These results reveal that higher numbers of viable mitochondria are correlated with more extensive autophagic mitochondrial quality maintenance in TIDA neurons as compared with NSDA neurons.

Diet with LPP for renal patients increases daily energy expenditure and improves motor function in parkinsonian patients with motor fluctuations

Objective

To establish whether a diet based on the usage of low-protein products for renal patients (LPP) is associated with higher energy expenditure (EE) than a free low-protein diet (NO-LPP) by calculating 24 h EE by indirect calorimetry using an electronic armband monitor.

Design

Randomized, cross-over, single-blind, pilot clinical trial performed comparing two different low-protein dietary regimens.

Subjects

Forty-two days with LPP and 42 days with NO-LPP regimen in six patients with Parkinson's disease with levodopa.

Methods

Monitoring patient response to two different nutritional schemes through indirect calorimetry (armband), BMI, Patient Global Improvement Scale.

Results

Mean total EE was 1731 ± 265 kcal/day with NO-LPP vs. 1903 ± 265 kcal/day with LPP (p = 0.02).

Conclusions

The usage of LPP increases EE and improves motor function in PD patients to a greater extent than NO-LPP dietary regimen. Calorie intake should be increased to prevent malnutrition in the long-term.

Sponsorship

Fondazione Grigioni per il Morbo di Parkinson.

The Degenerative Dysarthrias: A Window into Critical Clinical and Research Issues

Although diversity of symptoms and urgency of needs pose many challenges, management of the degenerative dysarthrias is a crucial aspect of clinical practice. The purpose of this article is to review current research literature on selected degenerative dysarthrias including those associated with Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis. These dysarthrias are prevalent yet represent distinct patterns of underlying neuropathology, symptoms, age of onset, and rate of progression. Literature searches including the period 1997-2006 yielded 148 different studies reporting data on communication issues related to dysarthria. By far the largest category of studies was that which provided a basic description of speech production including the neurophysiologic, acoustic, or perceptual properties of dysarthria. Other categories included management (assessment and treatment) and the psychosocial consequences of dysarthria. While the topic of management of degenerative dysarthria is a focused one, it provides a window into many issues critical to the field of communication disorders including fundamental properties of speech production, development of evidence-based treatment techniques, the staging of these techniques into an effective management sequence, and the psychosocial consequences of communication disorders along with techniques to maintain communicative participation in the face of degenerative conditions.

In vivo induction of heat shock proteins in the substantia nigra following L-DOPA administration is associated with increased activity of mitochondrial complex I and nitrosative stress in rats: regulation by glutathione redox state

Increasing evidence suggests a critical role for oxidative and nitrosative stress in the pathogenesis of most important neurodegenerative disorders. Parkinson's disease (PD) is a neurodegenerative disease characterized by a severe depletion in number of dopaminergic cells of the substantia nigra (SN). Administration of L-DOPA (LD) is the more effective treatment for patients with PD. However, the vast majority of patients suffer LD-related complications, which represent the major problem in the clinical management of PD. In the present study, LD administration to rats resulted in a significant dose-dependent increase in Hsp70 synthesis which was specific for the SN. The amount of 70 kDa protein increased after 6 h treatment reaching the maximal induction after 24-48 h. Induction of Hsp70 in the SN was associated with a significant increase in constitutive Hsc70 and mitochondrial Hsp60 stress proteins, and with increased expression of mitochondrial complex I whereas no significant changes were found in the activity of complex IV. In the same experimental conditions, a significant decrease in reduced glutathione was observed, which was associated with an increased content of oxidized glutathione content as well as nitric oxide (NO) synthase activity, NO metabolites and nitrotyrosine immunoreactivity. Interestingly, Hsp70 induction, iNOS up-regulation and nitrotyrosine formation have been confirmed also in SN and striatum of rats treated with LD and carbidopa, this latter being an inhibitor of the peripheral DOPA decarboxylase. Our data are in favor of the importance of the heat shock signal pathway as a basic mechanism of defense against neurotoxicity elicited by free radical oxygen and nitrogen species produced in aging and neurodegenerative disorders.

Medical management of advanced Parkinson's disease

The management of advancing Parkinson's disease (PD) is a daunting task, complicated by dynamic medication responses, side effects, and treatment-refractory symptoms in an aging patient population. The motor and nonmotor complications of advancing PD are reviewed, and practical treatment strategies are provided. Careful assessment in the context of the known natural history of advancing PD and rational treatment choices can create significant improvement in the lives of patients who have advancing PD.

Body weight gain rate in patients with Parkinson's disease and deep brain stimulation

We evaluated body weight changes in patients with Parkinson's disease (PD) after electrode implantation for deep brain stimulation (DBS) in the subthalamic nucleus (STN) in relation to clinical improvement. Thirty PD patients who received STN DBS were included (22 men, 8 women; mean age, 60.0 +/- 7.1 years; mean PD duration, 13.5 +/- 3.7 years; mean body mass index [BMI], 21.6 +/- 3.0 kg/m2). Body weight, physical activity, and Unified Parkinson's Disease Rating Scale (UPDRS) scores were noted before and 3 and 12 months after the procedure. Significant weight gain occurred in 29 patients; the mean increase was 14.8 +/- 9.8% of initial body weight in 1 year. Of the patients, 46.5% reported weight gain in the first 3 months, 21.4% gradual weight gain in the first 6 months, and 32.1% a slow increase for 1 year. Mean BMI increased up to 24.7 +/- 3.7 kg/m2. After 1 year, mean UPDRS motor score improved significantly in off and in on; and therapy complications improved by 91.0 +/- 17.0%. BMI changes at 3 and 12 months were significantly correlated to dyskinesia score changes, and levodopa dosage was not. In PD, STN DBS produces not only symptom control, but also weight gain. DBS candidates should be given nutritional counseling before the intervention to prevent rapid and/or excessive weight gain.

Parkinson's disease: is the initial treatment established?

Recent studies have suggested that initial dopamine agonist therapy with pramipexole or ropinirole may slow the progression of Parkinson's disease (PD) and also reduce the subsequent risk of levodopa motor complications. This presumed effect on PD progression, however, could be artifactual, resulting from the influence of chronic drug treatment on regulation of dopamine system proteins. With respect to levodopa motor complications, there is no dispute that pramipexole and ropinirole are effective in reducing levodopa dyskinesias and motor fluctuations; however, it is not clear that they must be started early, as opposed to initiation only after the levodopa complications develop. Levodopa therapy has numerous advantages that include greater efficacy, much lesser expense, simpler administration, and a lower frequency of hallucinosis and somnolence. Carbidopa/levodopa, pramipexole, and ropinirole are all appropriate first choices in the treatment of PD.

Is underweightness still a major problem in Parkinson's disease patients?

OBJECTIVE

To evaluate the current rate of underweightness amongst Parkinson's disease (PD) patients at an Italian referral centre.

DESIGN

Epidemiological study on consecutive patients presenting for the first time in a 16-month period.

SETTING

Nutritional service of PD referral centre in Milan, Italy.

SUBJECTS

Three-hundred and sixty-four PD patients diagnosed according to CAPIT criteria.

METHODS

Anthropometric assessments: BMI and waist-to-hip ratio; evaluation of therapeutic physical activity (h/week).

RESULTS

Three-hundred and sixty-four patients were included (180 female, 184 male), mean (s.d.) age 65.9 (8.9) y, mean (s.d.) duration of PD 10.6 (5.3) y; 134 patients (37%) were overweight and 92 (25%) were obese; 11 (3%) were underweight; 127 (35%) had normal BMI. No important differences in BMI according to sex and smoking status were observed. There was highly significant inverse correlation between duration of disease and BMI (P<0.001): mean (s.d.) duration of disease was 9.7 (4.7) y in overweight+obese patients, 11.1 (5.5) y in patients with normal BMI and 14.1 (7.2) y in underweight patients (P=0.0059). The waist-to-hip ratio was a cardiovascular risk factor in 47.7% of men and 73.8% of women. Mean (s.d.) therapeutic physical activity was 1.07 (1.59) h/week in overweight and obese patients vs 1.61 (2.04) h/week in patients with normal BMI (50.5% increase; P=0.03).

CONCLUSIONS

At present underweightness is uncommon in PD patients in Italy; this may be due to the increase in the prevalence of overweightness in the Italian population and to modern antiparkinsonian therapy.

Cellular polyamines promote the aggregation of alpha-synuclein

The cellular polyamines putrescine, spermidine, and spermine accelerate the aggregation and fibrillization of alpha-synuclein, the major protein component of Lewy bodies associated with Parkinson's disease. Circular dichroism and fluorometric thioflavin T kinetic studies showed a transition of alpha-synuclein from unaggregated to highly aggregated states, characterized by lag and transition phases. In the presence of polyamines, both the lag and transition times were significantly shorter. All three polyamines accelerated the aggregation and fibrillization of alpha-synuclein to a degree that increased with the total charge, length, and concentration of the polyamine. Electron and scanning force microscopy of the reaction products after the lag phase revealed the presence of aggregated particles (protofibrils) and small fibrils. At the end of the transition phase, alpha-synuclein formed long fibrils in all cases, although some morphological variations were apparent. In the presence of polyamines, fibrils formed large networks leading ultimately to condensed aggregates. In the absence of polyamines, fibrils were mostly isolated. We conclude that the polyamines at physiological concentrations can modulate the propensity of alpha-synuclein to form fibrils and may hence play a role in the formation of cytosolic alpha-synuclein aggregates.