No abstract

Background Levodopa is the most effective therapy for Parkinson's disease (PD), but chronic treatment is associated with the development of potentially disabling motor complications. Experimental studies suggest that motor complications are due to non-physiologic, intermittent administration of the drug, and can be reduced with continuous delivery. Levodopa-carbidopa intestinal gel (LCIG) is a form of levodopa that can be delivered continuously through an intrajejunal percutaneous tube. Methods We performed a 12-week double-blind, double-dummy, double-titration, multi-center trial to evaluate the efficacy and safety of LCIG compared to optimized, oral, immediate-release levodopa-carbidopa (LC-IR) in advanced PD patients with motor complications. The primary endpoint was change from baseline to final visit in motor “Off” time. Motor “On” time without troublesome dyskinesia was the key secondary endpoint. Findings 71 patients with advanced PD were randomized to receive continuous LCIG infusion plus placebo LC-IR capsules (n=37) or to receive LC-IR capsules plus continuous placebo LCIG infusion (n=34). Both groups were titrated to optimal effect. 93% of subjects (n=66) completed the trial. In comparison to LC-IR, LCIG significantly reduced “Off” time by a mean (±SE) of 1·91±0·57 hours (P=0·0015) and increased “On” time without troublesome dyskinesia by a mean of 1·86±0·65 hours (P=0·006). Adverse events were primarily related to the surgical procedure and the device, and while potentially serious, were not associated with residual deficit or mortality. Interpretation In comparison to standard oral LC-IR, LCIG significantly reduced “Off” time and increased “On” time without troublesome dyskinesia in patients with advanced PD. Adverse events were largely due to the procedure and the device. Benefits are of greater magnitude than have been obtained with medical therapies to date, and represent the first demonstration of the benefit of continuous levodopa delivery in a double-blind controlled study.

Progressive supranuclear palsy (PSP) is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common being Alzheimer’s disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 PSP cases and 3,247 controls (Stage 1) followed up by a second stage where 1,051 cases and 3,560 controls were genotyped for Stage 1 SNPs that yielded P ≤ 10−3. We found significant novel signals (P < 5 × 10−8) associated with PSP risk at STX6, EIF2AK3, and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response, and for a myelin structural component.

Huntington's disease (HD) is an inherited neurodegenerative disease caused by expansion of a polyglutamine tract in the huntingtin protein. Transcriptional dysregulation has been implicated in HD pathogenesis. Here, we report that huntingtin interacts with the transcriptional activator Sp1 and coactivator TAFII130. Coexpression of Sp1 and TAFII130 in cultured striatal cells from wild-type and HD transgenic mice reverses the transcriptional inhibition of the dopamine D2 receptor gene caused by mutant huntingtin, as well as protects neurons from huntingtin-induced cellular toxicity. Furthermore, soluble mutant huntingtin inhibits Sp1 binding to DNA in postmortem brain tissues of both presymptomatic and affected HD patients. Understanding these early molecular events in HD may provide an opportunity to interfere with the effects of mutant huntingtin before the development of disease symptoms.