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Introduction: Spinocerebellar ataxia type 3 (SCA-ATXN3) is a genetic neurodegenerative disease characterized by progressive cerebellar ataxia and other variable findings, including Parkinsonian syndrome. There is no disease-modifying treatment for SCA-ATXN3, so symptom-based management predominates. We aim to illustrate the disease's phenotypic variability and describe the effectiveness of advanced therapies in Parkinsonian symptoms.Cases: We present two patients with a predominant levodopa-responsive Parkinsonian phenotype, combined with cerebellar features. We achieved an optimal control of Parkinsonian symptoms with a carbidopa-levodopa intestinal gel infusion pump.Conclusions: We should suspect an SCA-ATXN3 etiology in patients with syndromes resembling an early-onset Parkinson disease with an autosomal dominant pattern. These patients could benefit from anti-Parkinsonian treatments, including levodopa intestinal gel infusion pump. [ABSTRACT FROM AUTHOR]

Introduction: Dopamine replacement via levodopa (LD) remains the most effective treatment for Parkinson's disease (PD), yet its use is often associated with motor complications within several years of continued use. The Accordion Pill® (AP-CD/LD) is a novel drug delivery system based on gastric retention of multilayer films containing immediate-release (IR) carbidopa (CD) and immediate- and controlled-release LD. The AP-CD/LD was designed to improve the consistency of LD in the bloodstream while offering patients with PD more consistent symptom management.Methods: This phase 2, multicenter, open-label, two-way randomized crossover study included 4 cohorts of participants with PD, each receiving AP-CD/LD (50/250 mg, 50/375 mg or 50/500 mg) twice daily in one treatment period and an active comparator in the other treatment period. Pharmacokinetics (PK) and efficacy were evaluated for AP-CD/LD vs IR-CD/LD. Treatment-emergent adverse events (TEAEs) and patient- and investigator-reported measures were also evaluated.Results: Compared with IR-CD/LD, treatment with either AP-CD/LD dose resulted in more stable LD plasma concentrations in both fluctuating and non-fluctuating PD patients, and significantly decreased Cmax (57.1% and 66.8% decreases among fluctuating and non-fluctuating patients, respectively). Both AP doses significantly improved standard measures of motor symptoms: (daily OFF time, total ON time, and good ON time), as well as patient- and investigator-assessed measures, versus IR-CD/LD. The safety and tolerability profile of AP-CD/LD was consistent with the known properties of IR-CD/LD.Conclusions: AP technology demonstrated effective controlled-release PK performance and reduced motor response fluctuations in advanced PD patients. A phase 3 randomized controlled trial is currently underway. [ABSTRACT FROM AUTHOR]

Dissociation of vasomotor and metabolic responses to levodopa has been observed in human subjects with Parkinson's disease (PD) studied with PET and in autoradiograms from 6-hydroxydopamine (6-OHDA) rat. In both species, acute levodopa administration was associated with increases in basal ganglia cerebral blood flow (CBF) with concurrent reductions in cerebral metabolic rate (CMR) for glucose in the same brain regions. In this study, we used a novel dual-tracer microPET technique to measure CBF and CMR levodopa responses in the same animal. Rats with unilateral 6-OHDA or sham lesion underwent sequential 15O-water (H215O) and 18F-fluorodeoxyglucose (FDG) microPET to map CBF and CMR following the injection of levodopa or saline. A subset of animals was separately scanned under ketamine/xylazine and isoflurane to compare the effects of these anesthetics. Regardless of anesthetic agent, 6-OHDA animals exhibited significant dissociation of vasomotor (ΔCBF) and metabolic (ΔCMR) responses to levodopa, with stereotyped increases in CBF and reductions in CMR in the basal ganglia ipsilateral to the dopamine lesion. No significant changes were seen in sham-lesioned animals.These data faithfully recapitulate analogous dissociation effects observed previously in human PD subjects scanned sequentially during levodopa infusion. This approach may have utility in the assessment of new drugs targeting the exaggerated regional vasomotor responses seen in human PD and in experimental models of levodopa-induced dyskinesia.

Telomeres, which are repetitive sequences that cap the end of the chromosomes, shorten with each cell division. Besides cellular aging, there are several other factors that influence telomere length (TL), in particular, oxidative stress and inflammation, which play an important role in the pathogenesis of neurodegenerative brain diseases including Parkinson’s disease (PD). So far, the majority of studies have not demonstrated a significant difference in TL between PD patients and healthy individuals. However, studies investigating the effect of TL on the symptomatology and disease progression of PD are scarce, and thus, warranted. We analyzed TL of peripheral blood cells in a sample of 204 PD patients without concomitant autoimmune diseases and analyzed its association with several PD related phenotypes. Monochrome multiplex quantitative PCR (mmqPCR) was used to determine relative TL given as a ratio of the amount of DNA between the telomere and albumin as the housekeeping gene. We found a significant difference in the relative TL between PD patients with and without dementia, where shorter TL presented higher risk for dementia (p = 0.024). However, the correlation was not significant after adjustment for clinical factors (p = 0.509). We found no correlations between TLs and the dose of dopaminergic therapy when the analysis was adjusted for genetic variability in inflammatory or oxidative factors. In addition, TL influenced time to onset of motor complications after levodopa treatment initiation (p = 0.0134), but the association did not remain significant after adjustment for age at inclusion and disease duration (p = 0.0781). Based on the results of our study we conclude that TL contributes to certain PD-related phenotypes, although it may not have a major role in directing the course of the disease. Nevertheless, this expends currently limited knowledge regarding the association of the telomere attrition and the disease severity or motor complications in Parkinson’s disease.

ABSTRACT: L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesias (LIDs) represent the main side effect of Parkinson's Disease (PD) therapy. Among the various pharmacological targets for novel therapeutic approaches, the serotonergic system represents a promising one. In experimental models of PD and in PD patients the development of abnormal involuntary movements (AIMs) and LIDs, respectively, is accompanied by the impairment of bidirectional synaptic plasticity in key structures such as striatum. Recently, it has been shown that the 5-HT1A/1B receptor agonist, eltoprazine, significantly decreased LIDs in experimental PD and human patients. Despite the fact that several papers have tested this and other serotonergic drugs, nothing is known about the electrophysiological consequences on this combined serotonin receptors modulation at striatal neurons.The present study demonstrates that activation of 5-HT1A/1B receptors reduces AIMs via the restoration of Long-Term Potentiation (LTP) and synaptic depotentiation in a sub-set of striatal spiny projection neurons (SPNs). This recovery is associated with the normalization of D1 receptor-dependent cAMP/PKA and ERK/mTORC signaling pathways, and the recovery of NMDA receptor subunits balance, indicating these events as key elements in AIMs induction. Moreover, we analyzed whether the manipulation of the serotonergic system might affect motor behavior and cognitive performances. We found that a defect in locomotor activity in parkinsonian and L-DOPA-treated rats was reversed by eltoprazine treatment. Conversely, the impairment in the striatal-dependent learning was found exacerbated in L-DOPA-treated rats and eltoprazine failed to recover it.

Objective: Recent studies showed high plasma homocysteine levels in patients treated with Levodopa for Parkinson’s disease (PD). Homocysteine, due to its exotoxic effect, might be the cause of polyneuropathy seen in PD. In this study, our aim was to show the correlation between high concentration of plasma homocysteine levels and polyneuropathy associated with PD.. Material and Methods: Forty-one patients with PD receiving levodopa treatment (patient group) and 30 healthy subjects (control group) were included in this study. We compared the two groups in terms of electrophysiological findings. Twelve patients had high plasma homocysteine levels and 29 of them had low plasma homocysteine levels. Results: Six of the 41 patients had sensorial polyneuropathy and decreased compound muscle action potantiel amplitude compared to controls. Two patients had high plasma homocysteine levels, two patients had nearly high plasma homocysteine levels, two patients had low plasma homocysteine levels who had sensorial polyneuropathy. Conclusion: Although in our study, we did not show any correlation between polyneuropathy and high plasma homocysteine levels, further studies including homogeneous groups of younger patients with PD are needed. (The Me di cal Bul - le tin of Ha se ki 2012; 50: 53-8)

The long-term replacement therapy with the dopamine (DA) precursor 3,4-dihydroxy-l-phenylalanine (L-DOPA) is a milestone in the treatment of Parkinson's disease (PD). Although this drug precursor can be metabolized into the active neurotransmitter DA throughout the brain, its therapeutic benefit is due to restoring extracellular DA levels within the dorsal striatum, which lacks endogenous DA as a consequence of the neurodegenerative process induced by the disease. In the early phases of PD, L-DOPA treatment is able to restore both long-term depression (LTD) and long-term potentiation (LTP), two major forms of corticostriatal synaptic plasticity that are altered by dopaminergic denervation. However, unlike physiological DA transmission, this therapeutic approach in the advanced phase of the disease leads to abnormal peaks of DA, non-synaptically released, which are supposed to trigger behavioural sensitization, namely L-DOPA-induced dyskinesia. This condition is characterized by a loss of synaptic depotentiation, an inability to reverse previously induced LTP. In the advanced stages of PD, L-DOPA can also induce non-motor fluctuations with cognitive dysfunction and neuropsychiatric symptoms such as compulsive behaviours and impulse control disorders. Although the mechanisms underlying the role of L-DOPA in both motor and behavioural symptoms are still incompletely understood, recent data from electrophysiological and imaging studies have increased our understanding of the function of the brain areas involved and of the mechanisms implicated in both therapeutic and adverse actions of L-DOPA in PD patients. [ABSTRACT FROM AUTHOR]

Objective: Recent studies showed high plasma homocysteine levels in patients treated with Levodopa for Parkinson's disease (PD). Homocysteine, due to its exotoxic effect, might be the cause of polyneuropathy seen in PD. In this study, our aim was to show the correlation between high concentration of plasma homocysteine levels and polyneuropathy associated with PD.. Material and Methods: Forty-one patients with PD receiving levodopa treatment (patient group) and 30 healthy subjects (control group) were included in this study. We compared the two groups in terms of electrophysiological findings. Twelve patients had high plasma homocysteine levels and 29 of them had low plasma homocysteine levels. Results: Six of the 41 patients had sensorial polyneuropathy and decreased compound muscle action potantiel amplitude compared to controls. Two patients had high plasma homocysteine levels, two patients had nearly high plasma homocysteine levels, two patients had low plasma homocysteine levels who had sensorial polyneuropathy. Conclusion: Although in our study, we did not show any correlation between polyneuropathy and high plasma homocysteine levels, further studies including homogeneous groups of younger patients with PD are needed. (The Medical Bulletin of Haseki 2012; 50: 53-8) [ABSTRACT FROM AUTHOR]

Abstract: Objective: Few studies confirm that pharmacological treatments support post-stroke recovery. The purpose of this study was to determine whether the combination of levodopa with language therapy improves aphasia rehabilitation. Methods: We did a prospective, randomized, placebo-controlled, double-blind study in which twenty patients received levodopa before each language therapy session, and an additional 19 received a placebo. Language training was provided during a 3-week period. The efficacy variables were changes from baseline in Boston Diagnostic Aphasia Examination (BDAE) scores. Results: Patients receiving levodopa experienced greater language improvement in verbal fluency and repetition, compared to patients receiving placebo. Improvement was particularly distinct in patients with anterior lesions. Conclusions: Supplementing language therapy with levodopa may improve recovery from aphasia in patients with frontal lesions. [Copyright &y& Elsevier]

We compared the metabolic and neurovascular effects of levodopa (LD) therapy for Parkinson's disease (PD). Eleven PD patients were scanned with both [15O]-H2O and [18F]-fluorodeoxyglucose positron emission tomography in the unmedicated state and during intravenous LD-infusion. Images were used to quantify LD-mediated changes in the expression of motor- and cognition-related PD covariance patterns in scans of cerebral blood flow (CBF) and cerebral metabolic rate for glucose (CMR). These changes in network activity were compared with those occurring during subthalamic nucleus (STN) deep brain stimulation (DBS), and those observed in a test-retest PD control group. Separate voxel-based searches were conducted to identify individual regions with dissociated treatment-mediated changes in local cerebral blood flow and metabolism. We found a significant dissociation between CBF and CMR in the modulation of the PDmotor-related network by LD treatment (p<0.001). This dissociation was characterized by reductions in network activity in the CMR scans (p<0.003) occurring concurrently with increases in the CBF scans (p<0.01). Flow-metabolism dissociation was also evident at the regional level, with LD-mediated reductions in CMR and increases in CBF in the putamen/globus pallidus, dorsal midbrain/pons, STN, and ventral thalamus. CBF responses to LD in the putamen and pons were relatively greater in patients exhibiting drug-induced dyskinesia. In contrast, flow-metabolism dissociation was not present in the STN DBS treatment group or in the PD control group. These findings suggest that flow-metabolism dissociation is a distinctive feature of LD treatment. This phenomenon may be especially pronounced in patients with LD-induced dyskinesia. [ABSTRACT FROM AUTHOR]

Patients with Parkinson's disease (PD) by definition benefit from treatment with the dopamine precursor levodopa. However, after 5 years of therapy 50% of patients experience motor response complications (MRC's): the benefit from each dose becomes shorter (wearing-off fluctuations), more unpredictable (on-off fluctuations) and associated with involuntary movements (dyskinesias). In addition these patients suffer from fluctuations in motor function that are inherent to the disease itself. Recent findings have lead to the suggestion that hyperfunction of NMDA receptors on striatal efferent neurons, as a consequence of chronic non-physiologic dopaminergic stimulation, contributes to the pathogenesis of MRC's. In PD patients blockade of striatal glutamate receptors with several NMDA-antagonists improve MRC's. With progression of PD the severity and complexity of MRC's magnify, obfuscating their pattern and their relation to the medication cycle. Only through detailed history taking and patient education will the physician be able to clarify the situation and establish a rational, targeted approach to the treatment of patients with advanced PD complicated by motor fluctuations and dyskinesias. [ABSTRACT FROM AUTHOR]

Centrally and locally elicited sympathetic vasoconstrictor responses were examined in 12 patients with symptoms and signs of cardiovascular autonomic dysfunction due to Parkinson's disease. The sympathetic reflex mechanisms were measured in skeletal muscle and subcutaneous tissue of the arm and leg using the 133-Xenon washout technique. This method allows differentiation between local and central sympathetic reflexes in different tissues. The results indicate an abolished centrally mediated vasoconstrictor response in skeletal muscle in the arm and a decreased response in skeletal muscle in the leg and in subcutaneous tissue. This is in agreement with an autonomic dysfunction located in the central nervous system. A possible spinal sympathetic reflex controlling blood flow in subcutaneous tissue and leg muscles is considered. The sympathetic vasoconstrictor responses in parkinsonian patients without autonomic failure were of normal magnitude and the responses were not affected by long-term levodopa treatment. [ABSTRACT FROM AUTHOR]

High-speed memory scanning (Sternberg paradigm) was tested in a collective of 20 parkinsonian patients (10 newly diagnosed, untreated patients, duration of the disease 0.5-3.8, mean 1.5 years; 10 levodopa-treated patients, duration of the disease 4.2 to 11, mean 7.6 years). The levodopa-treated patients stopped taking levodopa before the test. There was a tendency towards retarded memory scanning in the patients' collective compared with 20 healthy controls with similar ages and verbal IQs (p=0.076, Mann-Whitney U test). The mental slowing correlated significantly with bradykinesia and the sum-score of the Columbia University Parkinson Rating Scale (p=0.021 and 0.019; Spearman rank correlation). Kruskal-Wallis ANOVA revealed a significant mental slowing in the subgroup of patients with Parkinson's disease for >4 years compared with the newly diagnosed patients and the controls (H=8.54; p=0.019 and 0.006, Mann-Whitney U test). The findings suggest a mental slowing in Parkinson's disease, which is associated with the progression of parkinsonian motor symptoms and not with depression. [ABSTRACT FROM AUTHOR]

Telomeres, which are repetitive sequences that cap the end of the chromosomes, shorten with each cell division. Besides cellular aging, there are several other factors that influence telomere length (TL), in particular, oxidative stress and inflammation, which play an important role in the pathogenesis of neurodegenerative brain diseases including Parkinson's disease (PD). So far, the majority of studies have not demonstrated a significant difference in TL between PD patients and healthy individuals. However, studies investigating the effect of TL on the symptomatology and disease progression of PD are scarce, and thus, warranted. We analyzed TL of peripheral blood cells in a sample of 204 PD patients without concomitant autoimmune diseases and analyzed its association with several PD related phenotypes. Monochrome multiplex quantitative PCR (mmqPCR) was used to determine relative TL given as a ratio of the amount of DNA between the telomere and albumin as the housekeeping gene. We found a significant difference in the relative TL between PD patients with and without dementia, where shorter TL presented higher risk for dementia (p = 0.024). However, the correlation was not significant after adjustment for clinical factors (p = 0.509). We found no correlations between TLs and the dose of dopaminergic therapy when the analysis was adjusted for genetic variability in inflammatory or oxidative factors. In addition, TL influenced time to onset of motor complications after levodopa treatment initiation (p = 0.0134), but the association did not remain significant after adjustment for age at inclusion and disease duration (p = 0.0781). Based on the results of our study we conclude that TL contributes to certain PD-related phenotypes, although it may not have a major role in directing the course of the disease. Nevertheless, this expends currently limited knowledge regarding the association of the telomere attrition and the disease severity or motor complications in Parkinson's disease. [ABSTRACT FROM AUTHOR]