Movement disorders : official journal of the Movement Disorder Society
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Randomized Controlled Trial Multicenter Study
Droxidopa for the short-term treatment of symptomatic neurogenic orthostatic hypotension in Parkinson's disease (nOH306B).
Neurogenic orthostatic hypotension (nOH) results from failure of norepinephrine responses to postural change to maintain standing systolic blood pressure (s-SBP). Droxidopa is an oral prodrug of norepinephrine. Study nOH306 enrolled patients with Parkinson's disease (PD) and symptomatic nOH. ⋯ Adverse-event (AE) incidence was similar across groups, but 12.4% of droxidopa and 6.1% of placebo subjects withdrew because of AEs. The most common AEs on droxidopa (vs. placebo) were headache (13.5% vs. 7.3%) and dizziness (10.1% vs. 4.9%). Study nOH306B demonstrated subjective (OHSA item 1) and objective (s-SBP) evidence of short-term droxidopa efficacy (vs. placebo) for symptomatic nOH in PD.
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Spinocerebellar ataxias (SCAs) belong to polyglutamine repeat disorders and are characterized by a predominant atrophy of the cerebellum and the pons. Proton magnetic resonance spectroscopy ((1) H MRS) using an optimized semiadiabatic localization by adiabatic selective refocusing (semi-LASER) protocol was performed at 3 T to determine metabolite concentrations in the cerebellar vermis and pons of a cohort of patients with SCA1 (n=16), SCA2 (n=12), SCA3 (n=21), and SCA7 (n=12) and healthy controls (n=33). Compared with controls, patients displayed lower total N-acetylaspartate and, to a lesser extent, lower glutamate, reflecting neuronal loss/dysfunction, whereas the glial marker, myoinositol (myo-Ins), was elevated. ⋯ The neurometabolic profiles detected in patients underlie cell-specific changes in neuronal and astrocytic compartments that cannot be assessed by other neuroimaging modalities. The inverse correlation between metabolites from these two compartments suggests a metabolic attempt to compensate for neuronal damage in SCAs. Because these biomarkers reflect dynamic aspects of cellular metabolism, they are good candidates for proof-of-concept therapeutic trials. © 2015 International Parkinson and Movement Disorder Society.
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An inverse association between Parkinson disease (PD) and total vitamin D levels has been reported, but whether vitamin D from different sources, that is, 25(OH)D2 (from diet and supplements) and 25(OH)D3 (mainly from sunlight exposure), all contribute to the association is unknown. Plasma total 25(OH)D, 25(OH)D2, and 25(OH)D3 levels were measured by liquid chromatography-tandem mass spectrometry in PD patients (n = 478) and controls (n = 431). Total 25(OH)D was categorized by clinical insufficiency or deficiency; 25(OH)D2 and 25(OH)D3 were analyzed in quartiles. ⋯ Our data confirm the association between vitamin D deficiency and PD, and for the first time demonstrate an inverse association of 25(OH)D2 with PD. Given that 25(OH)D2 concentration is independent of sunlight exposure, this new finding suggests that the inverse association between vitamin D levels and PD is not simply attributable to lack of sunlight exposure in PD patients with impaired mobility. The current study, however, cannot exclude the possibility that gastrointestinal dysfunction, a non-motor PD symptom, contributes to the lower vitamin D2 levels in PD patients.