Effect of duodenal levodopa infusion on blood pressure and sweating

Parkinson's disease and skin

Parkinson's disease is associated with a variety of dermatologic disorders and the study of skin may provide insights into pathophysiological mechanisms underlying this common neurodegenerative disorder. Skin disorders in patients with Parkinson's disease can be divided into two major groups: 1) non-iatrogenic disorders, including melanoma, seborrheic dermatitis, sweating disorders, bullous pemphigoid, and rosacea, and 2) iatrogenic disorders related either to systemic side effects of antiparkinsonian medications or to the delivery system of antiparkinsonian therapy, including primarily carbidopa/levodopa, rotigotine and other dopamine agonists, amantadine, catechol-O-methyl transferase inhibitors, subcutaneous apomorphine, levodopa/carbidopa intestinal gel, and deep brain stimulation. Recent advances in our understanding of the role of α-synuclein in peripheral tissues, including the skin, and research based on induced pluripotent stem cells derived from skin fibroblasts have made skin an important target for the study of Parkinson's disease pathogenesis, drug discovery, novel stem cell therapies, and diagnostics.

Different response to instrumental tests in relation to cognitive demand after dopaminergic stimulation in previously treated patients with Parkinson's disease

Instrumental measurement of response assets and movement behaviour gained importance as addition to rating procedures to determine the efficacy of therapeutic interventions in patients with Parkinson's disease. Objectives were to determine the response to standardised 100 mg levodopa application with repeat performance of complex and simple instrumental tests in relation to scored motor behaviour in 53 previously treated patients. Levodopa improved rating scores of motor impairment, execution of complicated movement patterns and complex reaction time. Computed improvements in these instrumental test results correlated with each other. Execution of the simple reaction time paradigm and of plain movement sequences did not ameliorate after levodopa. The changes of these simple test results were not associated to each other. These different response patterns result from the higher cognitive demand of dopamine sensitive association areas of the prefrontal cortex and mesolimbic system for the complex test execution in contrast to the simple task performance.

Lipid-based nanodelivery approaches for dopamine-replacement therapies in Parkinson's disease: From preclinical to translational studies

The incidence of Parkinson's disease (PD), the second most common neurodegenerative disorder, has increased exponentially as the global population continues to age. Although the etiological factors contributing to PD remain uncertain, its average incidence rate is reported to be 1% of the global population older than 60 years. PD is primarily characterized by the progressive loss of dopaminergic (DAergic) neurons and/or associated neuronal networks and the subsequent depletion of dopamine (DA) levels in the brain. Thus, DA or levodopa (l-dopa), a precursor of DA, represent cardinal targets for both idiopathic and symptomatic PD therapeutics. While several therapeutic strategies have been investigated over the past decade for their abilities to curb the progression of PD, an effective cure for PD is currently unavailable. Even DA replacement therapy, an effective PD therapeutic strategy that provides an exogenous supply of DA or l-dopa, has been hindered by severe challenges, such as a poor capacity to bypass the blood-brain barrier and inadequate bioavailability. Nevertheless, with recent advances in nanotechnology, several drug delivery systems have been developed to bypass the barriers associated with central nervous system therapeutics. In here, we sought to describe the adapted lipid-based nanodrug delivery systems used in the field of PD therapeutics and their recent advances, with a particular focus placed on DA replacement therapies. This work initially explores the background of PD; offers descriptions of the most recent molecular targets; currently available clinical medications/limitations; an overview of several lipid-based PD nanotherapeutics, functionalized nanoparticles, and technical aspects in brain delivery; and, finally, presents future perspectives to enhance the use of nanotherapeutics in PD treatment.

Dopaminergic Therapies for Non-motor Symptoms in Parkinson's Disease

Apart from the typical motor symptoms, Parkinson's disease is characterized by a wide range of different non-motor symptoms, which are highly prevalent in all stages of the disease and have an incisive influence on quality of life. Moreover, their treatment continues to be challenging. In this review, we critically summarize the evidence for the impact of dopaminergic therapies on non-motor symptoms in Parkinson's disease. We performed a PubMed search to identify relevant clinical studies that investigated the response of non-motor symptoms to dopaminergic therapy. In the domain of neuropsychiatric disturbances, there is increasing evidence that dopamine agonists can ameliorate depression or anxiety. Other neuropsychiatric symptoms such as psychosis or impulse control disorders can also be worsened or even be induced by dopaminergic agents. For the treatment of sleep disturbances, it is essential to identify different subtypes of sleep pathologies. While there is for example profound evidence for the effectiveness of dopaminergic medication for the treatment of restless legs syndrome and sleep fragmentation, evidence for an improvement of rapid eye movement sleep behavior disorder is lacking. With regard to the broad spectrum of autonomic disturbances, response to dopaminergic treatment seems to differ largely, with on the one hand, some evidence for an improvement of sexual function or sweating with dopaminergic treatment, while on the other hand, constipation can be worsened. Finally, the analysis of sensory deficits reveals that some forms of pain, in particular fluctuation-dependent dystonic pain, can be well addressed by adapting the dopaminergic therapy, while no effect has been seen so far for hyposmia or visual deficits. Moreover, the occurrence of non-motor fluctuations is gaining increased attention, as they can be specifically addressed by a more continuous dopaminergic intake. Taken together, there is evidence of a good response of some (but not all) non-motor symptoms to dopaminergic therapy, which must be individually adapted to the special spectrum of symptoms.

Multifactorial sleep disturbance in Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder, ranking only behind Alzheimer's disease and affecting 2% of the population over the age of 65. Pathophysiologically, PD is characterized by selective degeneration of the dopaminergic neurons of the substantia nigra pars compacta (SNpc) and striatal dopamine depletion. Patients may also exhibit mild-to-severe degeneration of other central and peripheral nervous tissues. The most dramatic symptoms of the disease are profound dopamine-responsive motor disturbances, including bradykinesia, akinesia, rigidity, resting tremor, and postural instability. PD patients commonly present with debilitating non-motor symptoms, including cognitive impairment, autonomic nervous system dysfunction, and sleep disturbance. Of these, sleep disturbance is the most consistently reported, and likely represents a disorder integrative of PD-related motor impairment, autonomic nervous system dysfunction, iatrogenic insult, and central neurodegeneration. The pathophysiology of PD may also indirectly disrupt sleep by increasing susceptibility to sleep disorders, including sleep disordered breathing, periodic limb movements, and REM behavior disorder. In this review, we will discuss these systems representing a multifactorial etiology in PD sleep disturbance.

The Skin and Parkinson's Disease: Review of Clinical, Diagnostic, and Therapeutic Issues

BACKGROUND

Parkinson's disease (PD) and the skin are related in a number of ways, including clinical abnormalities of the disease itself and skin-related side effects of dopaminergic medication, pumps, and surgical therapies. Recent advances in understanding the role of α-synuclein suggest skin biopsies as a potential diagnostic or even a premotor marker of PD.

METHODS

The PubMed database was searched for publications up to October 2015, and the current evidence on skin-related issues in PD was comprehensively summarized.

RESULTS

The evidence was summarized on the prevalence, etiology, and management of seborrheic dermatitis, sweating dysfunctions, bullous pemphigoid, and malignant melanoma, as well as therapy-related skin disorders, especially those observed in amantadine, rotigotine, apomorphine, and levodopa/carbidopa intestinal gel therapies and deep-brain stimulation. Skin biopsies evaluating the presence of α-synuclein, the density and morphology of cutaneous nerves, and skin fibroblast functions also are discussed.

CONCLUSIONS

Skin disorders are a common manifestation of PD. However, the exact pathophysiology and prevalence of these disorders are not well understood, and more systematic research is needed in this regard. Peripheral tissue biopsies as a diagnostic marker of PD are an exciting avenue in future PD research, although multiple caveats and pending issues need to be solved before they can be used in routine clinical practice.

Long-term effectiveness of levodopa-carbidopa intestinal gel in 177 Spanish patients with advanced Parkinson's disease

AIM

To assess long-term effectiveness and tolerability of levodopa-carbidopa intestinal gel (LCIG) in Spanish patients with advanced Parkinson's disease.

PATIENTS & METHODS

This was an observational, multicenter, cross-sectional, retrospective study.

RESULTS

Data of 177 patients were analyzed. LCIG treatment led to a reduction in the percentage of daily 'off' time (16.2 vs 47.6% before LCIG), an increase in the percentage of daily 'on' time without disabling dyskinesia (55.6 vs 21.6%). Most patients experienced improvements in freezing of gait, tremor, dizziness, fatigue or flat mood. Adverse events related to levodopa, gastrostomy and technical issues were reported in 36.2, 42.4 and 43.5% of patients, respectively.

CONCLUSION

This study confirms the long-term effectiveness and safety profile of LCIG in patients with advanced Parkinson's disease.

Clinical management of patients with advanced Parkinson's disease treated with continuous intestinal infusion of levodopa/carbidopa

Patients with Parkinson's disease often have a good initial response to dopaminergic therapy but later usually develop motor fluctuations and dyskinesia. In these patients, continuous infusion of levodopa-carbidopa intestinal gel (LCIG) allows for maintaining adequate dopamine levels and for improving motor and nonmotor symptoms, as well as quality of life and autonomy. Adequate candidate selection and follow-up are crucial for treatment success. Management should be multidisciplinary, and patient and caregiver education is a priority. This expert consensus document has been developed by a team of neurologists, gastroenterologists and nurses who have a vast experience in LCIG therapy, with an intention to provide knowledge and tools to facilitate patient management throughout all phases of LCIG treatment process.

Parkinson's disease and the cardio-ankle vascular stiffness index

OBJECTIVE

To investigate the relationship between Parkinson's disease (PD) and the cardio-ankle vascular stiffness index (CAVI), a novel non-invasive measurement of vascular stiffness.

METHODS

A total of 63 PD subjects who underwent CAVI measurement were enrolled, including 30 men and 33 women 69.1±7.5 years of age (range: 46-79 years). Sixty-three non-PD subjects (30 men, 33 women, mean age: 68.7±7.6 years [range: 43-79 years]) served as controls. Comparisons between the control and PD subjects were made using Fisher's protected least significant difference, the Bonferroni-Dunn test, Scheffe's test and the unpaired t-test.

RESULTS

1) The average CAVI values were as follows: control, 9.3±0.9; PD, 9.0±1.0 (p=0.049). The differences in the CAVI values between the groups and the index values (normative data provided internally in the VaSera system) were as follows: control, 0.4±0.8; PD, 0.03±0.9 (p=0.011). The CAVI values of the PD patients were significantly smaller than those of the control subjects. 2) Among the control subjects, the CAVI values in the subjects with atherosclerotic risk factors (hypertension, dyslipidemia and/or diabetes) were significantly higher than those observed in the subjects without risk factors. In contrast, among the PD patients, the CAVI values in the subjects with atherosclerotic risk factors were equivalent to those observed in the subjects without risk factors. 3) Among the PD patients, the CAVI values did not change with the motor stage.

CONCLUSION

The results of the present study show that, compared with control subjects, PD patients exhibit normal CAVI values despite having mild but significant atherosclerotic risk factors, e.g., hypertension and diabetes. These findings suggest that PD patients are less vulnerable to systemic atherosclerosis than their risk factors may suggest.

Orthostatic hypotension in Parkinson’s disease

SUMMARY Orthostatic hypotension (OH) is a frequent non-motor symptom in Parkinson’s disease (PD), affecting between 22.9 and 38.4% of patients. In PD, OH is related to an increased risk of falls, and possibly to cognitive dysfunction and increased mortality. These data emphasize the importance of its prompt recognition and treatment. OH is related to pre- and post-ganglionic adrenergic denervation, but other factors, such as drugs, heat, meals or alcohol intake, might also induce or aggravate it. Evidence about the efficacy and safety of pharmacological or nonpharmacological strategies for OH treatment in PD is weak. Nonpharmacological measures include liberal addition of salt to the diet, exercise, compression stockings or physical maneuvers. Severe cases may be treated with midodrine or fludrocortisone. Some results suggest that droxidopa and fipamezole may be effective treatments. We finish this review article by discussing the most important unanswered questions about PD-related OH, which may be the focus of future research.

The management of orthostatic hypotension in Parkinson's disease

Orthostatic hypotension (OH) is a common and disabling symptom affecting Parkinson's disease (PD) patients. We present the effect of the different therapies commonly used to manage PD on this clinical manifestation. For this purpose, we describe the relationship between OH and the current treatments employed in PD, such as L-DOPA, dopaminergic agonists, and continuous dopaminergic stimulation therapies. Additionally, we review the therapeutic measures that could be used to ameliorate OH. There are different approaches to deal with this manifestation, including pharmacological and non-pharmacological treatments, although none of them is specifically aimed for treating OH in PD.