Prognostic utility of MicroRNA-221 and interleukin-6 in cerebral ischemic stroke.

Cerebral ischemic stroke has a significant mortality rate and persistent impairment. The initial diagnosis of stroke occurs by magnetic resonance imaging and computed tomography. There is a strong need for more accessible, less expensive, and non-invasive methods besides the neuroimaging methods. MicroRNAs (miRNAs) are critical regulators for ischemic stroke as they are involved in stroke pathophysiology. The goal of the current study was to determine whether microRNA-221 (miR-221) could be used as a diagnostic biomarker for patients with ischemic stroke, and whether it can serve as a promising indicator of the disease severity especially if combined with interleukin-6 (IL-6). The study included 90 subjects, 45 cerebral ischemic stroke patients and 45 controls. MiR-221 was evaluated by quantitative real-time polymerase chain reaction (q-PCR) and IL-6 by enzyme-linked immunosorbent assay (ELISA). Our study results revealed that the serum miR-221 level was significantly reduced in cerebral ischemic stroke patients when compared to the control group (p<0.0001). In addition, serum miR-221 showed a significant negative correlation with cerebral stroke severity (p<0.0001), whereas serum IL-6 showed a significant positive correlation with cerebral stroke severity (p < 0.0001). We also analyzed the receiver operator characteristic (ROC) curve and found that area under the ROC curve (AUC) for severity of ischemic stroke by miR-221 was 0.97 (95% confidence intervall0.93-1, p<0.001). Notably, the combination of serum miR-221 with IL-6 for prediction of ischemic stroke severity showed both increased sensitivity/specificity (AUC=0.99, 95% confidence interval 0.96-1, p<0.001) than miR-221 alone. We concluded that miR-221 constituted a non-invasive, sensitive, and specific biomarker that could be used for diagnosis of ischemic stroke and for prediction of its severity.

Evaluation of Heart Rate Variability Parameters During Awake and Sleep in Refractory and Controlled Epileptic Patients.

Background: Alterations of heart rate variability (HRV) in epileptic patients were the field of interest of several studies for many reasons, particularly the contribution toward sudden unexpected death in epilepsy (SUDEP). Aim: We aimed at evaluation of autonomic dysfunction in epileptic patients during awake and sleep in addition to studying the association between SUDEP risk with different Holter parameters. Patients and Methods: The study included eighty epileptic patients (40 controlled epileptic patients and 40 refractory epileptic patients) compared to 30 volunteers as control group. They underwent detailed epileptic history, Chalfont seizure severity scale, sudden unexpected death in epilepsy (SUDEP)-7 risk score and 24 hour Holter monitoring to assess HRV parameters. Results: Patients with refractory epilepsy had longer duration of epilepsy with increased number of used AEDs compared to controlled epileptic group. Both controlled and refractory epileptic patients had significantly higher average heart rate (AV.HR), sympatho-vagal ratio (low-frequency/high-frequency (LF/HF) ratio in 24 hours, daytime, and nighttime), and LF and HF values compared to controls. The rMSSD (the root mean square of difference between successive normal intervals), Tri.Index (triangular index), and pNN50 (percentage of the number of pairs of consecutive beat-to-beat intervals that varied by 50 ms) were significantly reduced in both epileptic groups compared to controls. Among refractory epileptic patients, patients with generalized epilepsy had significantly higher severity epileptic scale, average heart rate, minimum heart rate, and LF/HF night, in addition to lower rMSSD and pNN50 compared to patients with focal epilepsy. We found positive correlation between the following Holter indices (LF/HF 24, LF/HF day, and LF/HF night) and the duration of the epilepsy, while negative correlations between Tri.Index, LF, and HF and the epileptic duration were detected. SUDEP-7 risk was negatively correlated with pNN50 and rMSSD; meanwhile, it was positively correlated with LF/HF 24. The severity of epilepsy among refractory epileptic patients was positively correlated with average heart rate but negatively correlated with pNN50 and rMSSD. Using linear regression analysis, we found that pNN50 and rMSSD could predict SUDEP-7 risk and severity of epilepsy in refractory epileptic patients. Conclusion: Epileptic patients (particularly refractory patients with generalized EEG findings and long duration) had reduced heart rate variability and hence impairment of parasympathetic activity with increased susceptibility for adverse outcomes. Moreover, pNN50 and rMSSD could be used as predictors for SUDEP-7 risk as well as severity of epilepsy in refractory epileptic patients.

Evaluation of QT dispersion in epileptic patients and its association with SUDEP risk.

BACKGROUND: Mortality in epileptic patients was attributed to sudden unexpected death in epilepsy (SUDEP). The precise pathophysiology of SUDEP is not fully understood, yet prolongation of ventricular repolarization particularly QTc interval suggested to be one of the contributing risk factor for SUDEP. OBJECTIVES: We aimed at evaluation of QTc and QT dispersion (QTD) in patients with epilepsy (both refractory and well-controlled epilepsy) and their association with the epileptic severity and sudden unexplained death (SUDEP) risk. PATIENTS AND METHODS: The study included eighty epileptic patients (40 controlled epileptic patients and 40 refractory epileptic patients) compared to thirty non-epileptic volunteers as the control group (patients with history of cardiovascular comorbidities or exposure to antiarrhythmic drugs were excluded from the study). All participants were subjected to clinical evaluation including detailed epileptic history with assessment of SUDEP 7 risk, severity scale, 12 leads surface ECG to measure QTc & QTD, 24 h Holter monitoring to assess heart rate variability (HRV) parameters. RESULTS: Controlled and refractory epileptic patients demonstrated increased average QTc and QTD values compared to control group (450.1 ± 18.9 vs. 412.3 ± 12.3 ms, p < 0.0001, 452.1 ± 19.0 vs. 412.3 ± 12.3 ms, p < 0.0001 respectively) (45.6 ± 14.9 vs. 15.4 ± 6.8 ms, p < 0.001, 70.6 ± 18.1 vs. 15.4 ± 6.8 ms, p < 0.0001 respectively). Refractory epileptic patients had a significantly higher incidence of abnormal QTD > 50 ms compared to controlled epileptic patients (32.5% vs. 90%, p < 0.005). Refractory epileptic patients with generalized form had significantly higher severity scale in addition to significantly impaired rMSSD and pNN50 compared to those with focal form (1072.7 ± 722.7 vs. 429.1 ± 180.4, p < 0.03, 17.11 ± 4.6 vs. 26.4 ± 7.9 ms, p < 0.004 and 2.9 ± 1.8 vs. 7.8 ± 4.1%, p < 0.003 respectively). Among refractory epileptic patients, the duration of epilepsy, rMSSD and QTD significantly correlated with SUDEP-7 risk (r2 =0.199, p < 0.005, r2 =0.623, p < 0.0001 and r2=0.44, p < 0.0001 respectively). CONCLUSIONS: The current study stands out the importance of evaluating QTc and QTD in 12-lead ECG recordings in epileptic patients and signifying their association with SUDEP-7 risk among refractory epileptic patients.