Debate is ongoing regarding when, why, and how to initiate pharmacotherapy for Parkinson's disease. Early initiation of dopaminergic therapies does not convey disease-modifying effects but does ...reduce disability. Concerns about the development of motor complications arising from the early initiation of levodopa, which led to misconceived levodopa-sparing strategies, have been largely mitigated by the outcomes of the PD MED and Levodopa in Early Parkinson's Disease (LEAP) studies. The LEAP study also showed the potential for early improvement in quality of life, even when disability is negligible. Until more effective methods of providing stable dopamine concentrations are developed, current evidence supports the use of levodopa as initial symptomatic treatment in most patients with Parkinson's disease, starting with low doses and titrating to therapeutic threshold. Monoamine oxidase-B inhibitors and dopamine agonists can be reserved as potential adjunct treatments later in the disease course. Future research will need to establish effective disease-modifying treatments, address whether patients’ quality of life is substantially improved with early initiation of treatment rather than a wait and watch strategy, and establish whether new levodopa formulations will delay onset of dyskinesia.
Summary Background Levodopa is the most effective therapy for Parkinson's disease, but chronic treatment is associated with the development of potentially disabling motor complications. Experimental ...studies suggest that motor complications are due to non-physiological, intermittent administration of the drug, and can be reduced with continuous delivery. We aimed to assess efficacy and safety of levodopa-carbidopa intestinal gel delivered continuously through an intrajejunal percutaneous tube. Methods In our 12-week, randomised, double-blind, double-dummy, double-titration trial, we enrolled adults (aged ≥30 years) with advanced Parkinson's disease and motor complications at 26 centres in Germany, New Zealand, and the USA. Eligible participants had jejunal placement of a percutaneous gastrojejunostomy tube, and were then randomly allocated (1:1) to treatment with immediate-release oral levodopa-carbidopa plus placebo intestinal gel infusion or levodopa-carbidopa intestinal gel infusion plus oral placebo. Randomisation was stratified by site, with a mixed block size of 2 or 4. The primary endpoint was change from baseline to final visit in motor off-time. We assessed change in motor on-time without troublesome dyskinesia as a prespecified key secondary outcome. We assessed efficacy in a full-analysis set of participants with data for baseline and at least one post-baseline assessment, and imputed missing data with the last observation carried forward approach. We assessed safety in randomly allocated patients who underwent the percutaneous gastrojejunostomy procedure. This study is registered with ClinicalTrials.gov , numbers NCT00660387 and NCT0357994. Findings From baseline to 12 weeks in the full-analysis set, mean off-time decreased by 4·04 h (SE 0·65) for 35 patients allocated to the levodopa-carbidopa intestinal gel group compared with a decrease of 2·14 h (0·66) for 31 patients allocated to immediate-release oral levodopa-carbidopa (difference −1·91 h 95% CI −3·05 to −0·76; p=0·0015). Mean on-time without troublesome dyskinesia increased by 4·11 h (SE 0·75) in the intestinal gel group and 2·24 h (0·76) in the immediate-release oral group (difference 1·86 95% CI 0·56 to 3·17; p=0·0059). In the safety analyses 35 (95%) of 37 patients allocated to the levodopa-carbidopa intestinal gel group had adverse events (five 14% serious), as did 34 (100%) of 34 patients allocated to the immediate-release oral levodopa-carbidopa group (seven 21% serious), mainly associated with the percutaneous gastrojejunostomy tube. Interpretation Continuous delivery of levodopa-carbidopa with an intestinal gel offers a promising option for control of advanced Parkinson's disease with motor complications. Benefits noted with intestinal gel delivery were of a greater magnitude than were those obtained with medical therapies to date, and our study is, to our knowledge, the first demonstration of the benefit of continuous levodopa delivery in a double-blind controlled study. Funding AbbVie.
Functional tremor Schwingenschuh, Petra; Espay, Alberto J.
Journal of the neurological sciences,
04/2022, Letnik:
435
Journal Article
Recenzirano
Odprti dostop
Functional tremor is the most common functional movement disorder. It can be diagnosed with clinically definite certainty at the bedside by ascertaining its inconsistent (distractibility, frequency ...variability) and incongruent features (entrainment, ballistic suppression), requiring no additional neurological investigations except, in selected cases, those serving to elevate the diagnostic category to laboratory supported using accelerometry and surface electromyography. In the background of excessive attention to the affected body part and abnormal beliefs and expectations, functional correlates include the impairment of emotion processing, sense of agency, and abnormal connectivity between limbic and motor regions. While the treatment options remain under-studied, promising interventions in physiotherapy, cognitive behavioral therapy, and other psychotherapies are under evaluation to assessing their efficacy in attenuating this important source of neurological disability.
This article is part of the Special Issue “Tremor” edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.
•Highly reliable clinical signs allow an inclusionary diagnosis of functional tremor.•Neurophysiology can provide a laboratory-supported diagnostic certainty in unclear cases.•Pathophysiological abnormalities include excessive attentional focus, discrepant beliefs / expectations, and abnormal sense of agency.•Psychological abnormalities are neither necessary nor sufficient for the diagnosis.•Early individually-tailored multidisciplinary treatment should be offered.
This Viewpoint makes a case for changing the approach in Parkinson disease research efforts from one of proteinopathy (accrual of amyloids) to proteinopenia (depletion of normal proteins).
Published diagnostic criteria for functional (psychogenic) movement disorders (FMDs) include psychiatric symptoms and some historical variables to affect the threshold between categories of ...diagnostic certainty. Clinically
probable
and
possible
categories, however, do not suffice to rule in FMD or rule out complex organic movement disorders and therefore are of little practical help. In contrast, a handful of
unequivocal and reliably incongruent or inconsistent
clinical features in each functional movement phenotype, when present, allow a
clinically definite
diagnosis of FMD, regardless of any psychiatric symptom. We suggest that the use of phenotype-specific clinically definite FMD diagnostic criteria will increase inter-rater reliability and minimize false-positive diagnostic errors. This process involves the ascertainment of core (mandatory) examination features instead of supportive but insufficiently sensitive historical, psychiatric, and inconsistent examination features.
The gold standard for a definitive diagnosis of Parkinson disease (PD) is the pathologic finding of aggregated α-synuclein into Lewy bodies and for Alzheimer disease (AD) aggregated amyloid into ...plaques and hyperphosphorylated tau into tangles. Implicit in this clinicopathologic-based nosology is the assumption that pathologic protein aggregation at autopsy reflects pathogenesis at disease onset. While these aggregates may in exceptional cases be on a causal pathway in humans (e.g., aggregated α-synuclein in SNCA gene multiplication or aggregated β-amyloid in APP mutations), their near universality at postmortem in sporadic PD and AD suggests they may alternatively represent common outcomes from upstream mechanisms or compensatory responses to cellular stress in order to delay cell death. These 3 conceptual frameworks of protein aggregation (pathogenic, epiphenomenon, protective) are difficult to resolve because of the inability to probe brain tissue in real time. Whereas animal models, in which neither PD nor AD occur in natural states, consistently support a pathogenic role of protein aggregation, indirect evidence from human studies does not. We hypothesize that (1) current biomarkers of protein aggregates may be relevant to common pathology but not to subgroup pathogenesis and (2) disease-modifying treatments targeting oligomers or fibrils might be futile or deleterious because these proteins are epiphenomena or protective in the human brain under molecular stress. Future precision medicine efforts for molecular targeting of neurodegenerative diseases may require analyses not anchored on current clinicopathologic criteria but instead on biological signals generated from large deeply phenotyped aging populations or from smaller but well-defined genetic–molecular cohorts.
PDF
