Alpha‐synuclein in peripheral tissues and body fluids as a biomarker for Parkinson's disease – a systematic review

Parkinson's disease (PD) is neuropathologically characterized as an alpha‐synucleinopathy. Alpha‐synuclein‐containing inclusions are stained as Lewy bodies and Lewy neurites in the brain, which are the pathological hallmark of PD. However, alpha‐synuclein‐containing inclusions in PD are not restricted to the central nervous system, but are also found in peripheral tissues. Alpha‐synuclein levels can also be measured in body fluids. The aim of this study was to conduct a systematic review of available evidence to determine the utility of alpha‐synuclein as a peripheral biomarker of PD. We searched PubMed (1948 to 26 May 2013), Embase (1974 to 26 May 2013), the Cochrane Library (up to 26 May 2013), LILACS (up to 26 May 2013) and CINAHL (up to 26 May 2013) for the studies of alpha‐synuclein in peripheral tissues or body fluids in PD. A total of 49 studies fulfilled the search criteria. Peripheral tissues such as colonic mucosa showed a sensitivity of 42–90% and a specificity of 100%; submandibular salivary glands showed sensitivity and specificity of 100%; skin biopsy showed 19% sensitivity and 80% specificity in detecting alpha‐synuclein pathology. CSF alpha‐synuclein had 71–94% sensitivity and 25–53% specificity for distinguishing PD from controls. Plasma alpha‐synuclein had 48–53% sensitivity and 69–85% specificity. Neither plasma nor CSF alpha‐synuclein is presently a reliable marker of PD. This differs from alpha‐synuclein in solid tissue samples of the enteric and autonomic nervous system, which offer some potential as a surrogate marker of brain synucleinopathy.     

State-Dependent Effects of Prefrontal Repetitive Transcranial Magnetic Stimulation on Emotional Working Memory

BackgroundA growing body of findings illustrates the importance of state-dependency in studies using brain stimulation.ObjectiveWe aimed to investigate the effects of tDCS priming followed by rTMS applied over the right dorsolateral prefrontal cortex (DLPFC) on emotional working memory.MethodsIn a randomized single-blind within-subjects design, participants performed an emotional 3-back task at baseline and after tDCS priming (anodal, cathodal) and subsequent low-frequency rTMS (active, sham) of the right DLPFC. Stimuli consisted of words related to the distinct emotion categories fear and anger as well as neutral words.ResultsTask accuracy increased for fear-related words and decreased for neutral words across stimulation conditions. No general state-dependent effects of prefrontal rTMS on working memory were found. We further showed a detrimental effect of negative emotional content on working memory performance.ConclusionsOur findings support a hemispheric lateralization of emotion processing by demonstrating that the withdrawal-related emotion fear is associated with the right DLPFC and contribute to clarifying the interaction between working memory and emotion.     

Does Concomitant Cholecystectomy at Time of Roux-en-Y Gastric Bypass Impact Adverse Operative Outcomes?

Background

We hypothesized that patients undergoing Roux-en-Y gastric bypass (RYGB) with concomitant cholecystectomy (RYGB + C) would be at greater risk for adverse events compared to patients undergoing RYGB alone.

Methods

Patients who underwent a RYGB were identified in the 2005–2009 American College of Surgeons National Surgical Quality Improvement Program Database. Multivariate logistic regression with adjustment for confounding variables was utilized to identify risk factors for mortality at 30 days, major adverse events, and prolonged length of stay (PLOS).

Results

We identified 32,946 patients who underwent RYGB; of these, 1,731 (5.2 %) underwent RYGB + C. Overall, RYGB + C was a risk factor for predicting major adverse events following laparoscopic but not open procedures. Regardless of approach, PLOS was more common among RYGB + C patients following adjustment. Overall mortality at 30 days was low and did not vary with concomitant cholecystectomy following adjustment.

Conclusions

The risk for major adverse events is significantly greater for RYGB + C patients following laparoscopic procedures, and the risk for PLOS is greater for RYGB + C patients following both open and laparoscopic procedures. The short-term risks identified in this study can assist in decision-making when considering concomitant cholecystectomy at the time of RYGB.     

Long-term outcomes following single-bundle transtibial arthroscopic posterior cruciate ligament reconstruction

Purpose

Posterior cruciate ligament (PCL) injury has a reported incidence of 3–20 %. PCL reconstruction is aimed at reducing onset of premature articular degeneration and improving function. Numerous operative techniques have been described with varying degrees of result consistency.

Methods

We evaluated 15 patients treated for isolated primary posterior cruciate ligament injury with a mean follow-up of 4.1 years (range one to nine). Post-reconstruction clinical assessment included the Lysholm and Tegner knee scoring scale, international knee documentation committee (IKDC) ligament evaluation, and KT2000 arthrometer assessment.

Results

On the Lysholm knee score 11 patients (73 %) had excellent results, three patients (20 %) had good results and one patient (7 %) had a poor result. On the Tegner activity score the majority of patients scored 7–8 with a return to high level sports. At the final follow-up, the post-reconstruction IKDC score was normal or nearly normal (A and B) in 14 (93 %) patients, and abnormal (C) in one (7 %) patient. According to KT-2000 arthrometer measurements at final follow-up review, 11 patients (73 %) were rated as normal (A, 0–2 mm), and four patients (27 %) as nearly normal (B, 3–5 mm). These results were independent of age, mechanism of injury, time elapsed to surgical reconstruction, and length of follow-up.

Conclusions

Despite being a technically demanding procedure, the outcomes reported in this study show that single bundle transtibial arthroscopic PCL repair using four strands hamstring autograft provides satisfactory and consistent functional outcomes.