Retinal functional and structural changes in patients with Parkinson's disease.

BACKGROUND: Visual dysfunction have been well reported as one of the non-motor symptoms in Parkinson's disease (PD). The aim of this study was to evaluate the functional and structural changes in the retina in patients with PD, and to correlate these changes with disease duration and motor dysfunction. METHODS: For this case-control study, we recruited patients fulfilling the diagnostic criteria for idiopathic PD according to British Brain Bank criteria, aged between 50 and 80 years. Age- and sex-matched healthy controls aged between 50 and 80 years were also recruited. Motor function for PD patients was assessed using Modified Hoehn and Yahr staging scale (H & Y staging) and Unified Parkinson's Disease Rating Scale (UPDRS). Optical Coherence Tomography (OCT) and full field electroretinogram (ff-ERG) were done to all participants. RESULTS: Data from 50 patients and 50 healthy controls were included in the analysis. Patients with idiopathic Parkinson's had significantly reduced peripapillary retinal nerve fiber layer (RNFL) thickness and macular ganglion cell complex (GCC) thickness compared to healthy controls (P-value < 0.05 in all parameters). They also had significantly delayed latency and reduced amplitude in both dark-adapted rods and the light-adapted cone for both a & b waves compared to healthy controls (P-value < 0.001 in all parameters). There were statistically significant negative correlations between disease duration, and left superior, right inferior and right & left average RNFL thickness [(r) coef. = -0.327, -0.301, -0.275, and -0.285 respectively]. UPDRS total score was negatively correlated with the amplitude of light-adapted of both RT and LT a & b wave and with dark-adapted RT b-wave latency [(r) coef. = -0.311, -0.395, -0.362, -0.419, and -0.342]. CONCLUSION: The retinal structure and function were significantly affected in patients with PD in comparison to healthy controls. There was a significant impact of disease duration on retinal thickness, and there was a significant negative correlation between the degree of motor dysfunction in patients with PD and retinal function.

The potential role of micro-RNA 125b-5p level in predicting outcome from thrombolytic therapy in patients with acute ischemic stroke.

Several studies highlighted a significant role of specific miRNA as diagnostic and prognostic biomarkers for acute ischemic stroke. The aim of this work was to study micro-RNA 125b-5p level in patients with acute ischemic stroke in relation to stroke etiology, risk factors, severity and outcome. This case-control study was conducted on 40 patients with acute ischemic stroke eligible for receiving rt-PA and 40 age and sex matched healthy controls, Patients were submitted to neurological and radiological assessment. Functional outcome after 3 months was assessed using the modified Rankin Scale (mRS). Plasma micro-RNA 125b-5p levels were measured for both patients and control groups by quantitative real time PCR. MiRNA-125b-5p was extracted from the plasma samples then Real-time quantitative reversed transcription PCR (RT-qPCR) analysis was done. To analyze miRNA-125b-5p expression in plasma, the ∆Cq value of miRNA-125b-5p was calculated by subtracting Cq of miRNA-125b-5p from the average Cq of MiRNA RNU6B. Stroke patients had significantly higher circulating micro-RNA 125b-5p levels in comparison to healthy controls (P value = 0.01). The circulating levels of micro-RNA 125b-5p were positively correlated with stroke severity assessed by National Institutes of Health Stroke Scale (NIHSS) and infarction size. Stroke patients with poor outcome had significantly higher circulating levels of micro-RNA 125b-5p in comparison to those with good outcome (P value ≤ 0.001). The circulating levels of micro-RNA 125b-5p were significantly higher in patients who developed complications after receiving rt-PA (P value ≤ 0.001). Logistic regression model revealed that each unit increase in micro-RNA125b-5p decreased the odds of good outcome by 0.095 (95% CI 0.016-0.58, P value = 0.011). Plasma micro-RNA 125b-5p is significantly elevated is ischemic stroke patients. It is positively correlated with stroke severity and strongly associated with poor outcome and complications after thrombolytic therapy.