A novel super-resolution microscopy platform for cutaneous alpha-synuclein detection in Parkinson's disease.

Alpha-synuclein (aSyn) aggregates in the central nervous system are the main pathological hallmark of Parkinson's disease (PD). ASyn aggregates have also been detected in many peripheral tissues, including the skin, thus providing a novel and accessible target tissue for the detection of PD pathology. Still, a well-established validated quantitative biomarker for early diagnosis of PD that also allows for tracking of disease progression remains lacking. The main goal of this research was to characterize aSyn aggregates in skin biopsies as a comparative and quantitative measure for PD pathology. Using direct stochastic optical reconstruction microscopy (dSTORM) and computational tools, we imaged total and phosphorylated-aSyn at the single molecule level in sweat glands and nerve bundles of skin biopsies from healthy controls (HCs) and PD patients. We developed a user-friendly analysis platform that offers a comprehensive toolkit for researchers that combines analysis algorithms and applies a series of cluster analysis algorithms (i.e., DBSCAN and FOCAL) onto dSTORM images. Using this platform, we found a significant decrease in the ratio of the numbers of neuronal marker molecules to phosphorylated-aSyn molecules, suggesting the existence of damaged nerve cells in fibers highly enriched with phosphorylated-aSyn molecules. Furthermore, our analysis found a higher number of aSyn aggregates in PD subjects than in HC subjects, with differences in aggregate size, density, and number of molecules per aggregate. On average, aSyn aggregate radii ranged between 40 and 200 nm and presented an average density of 0.001-0.1 molecules/nm2. Our dSTORM analysis thus highlights the potential of our platform for identifying quantitative characteristics of aSyn distribution in skin biopsies not previously described for PD patients while offering valuable insight into PD pathology by elucidating patient aSyn aggregation status.

CT-guided thrombolytic treatment of patients with wake-up strokes.

BACKGROUND: Observational studies of thrombolysis outcomes in wake-up acute ischemic stroke patients selected based on non-contrast brain CT criteria suggested that treated patients did as well as or better than those not treated, after adjustment for baseline characteristics. We began offering thrombolytic treatment (IVTPA) to patients presenting with wake-up strokes and normal non-contrast brain CTs, who could be treated within 4.5 h of being found. DESIGN/METHODS: A retrospective chart review was performed in patients presenting with AIS between November 2014 and December 2017 who received IVTPA. A planned subgroup analysis compared patients with wake-up strokes and normal non-contrast brain CTs to patients with witnessed stroke treated within 4.5 h of being found, or of witnessed onset, respectively. RESULTS: Three hundred and six patients were treated, 279 with witnessed-onset and 27 with wake-up strokes. The latter were not candidates for endovascular intervention. Efficacy and safety were similar in both groups. Discharges home, respectively, were 143(53%) and 13(48%); facility discharges were 112(40.1%) and 11(40.7%) and in-hospital mortality was 19 (6.8%) and 3 (11%). Treatment-related symptomatic bleeds were: 5(1.8%) and 1 (3.7%), respectively. CONCLUSIONS: The findings affirm, in a new clinical series reflecting routine practice, that it is safe to treat with IVTPA patients with wake-up strokes and a normal brain CT scan, who are not candidates for endovascular intervention. We hypothesize, that when the non-contrast brain CT scan is normal, it may be safe to extend beyond 4.5 h the IVTPA treatment eligibility window in similar patients with witnessed-onset stroke.