Multivariate analysis of risk factors for QT prolongation following subarachnoid hemorrhage

BACKGROUND: Subarachnoid hemorrhage (SAH) often causes a prolongation of the corrected QT (QTc) interval during the acute phase. The aim of the present study was to examine independent risk factors for QTc prolongation in patients with SAH by means of multivariate analysis. METHOD: We studied 100 patients who were admitted within 24 hours after onset of SAH. Standard 12-lead electrocardiography (ECG) was performed immediately after admission. QT intervals were measured from the ECG and were corrected for heart rate using the Bazett formula. We measured serum levels of sodium, potassium, calcium, adrenaline (epinephrine), noradrenaline (norepinephrine), dopamine, antidiuretic hormone, and glucose. RESULTS: The average QTc interval was 466 ± 46 ms. Patients were categorized into two groups based on the QTc interval, with a cutoff line of 470 ms. Univariate analyses showed significant relations between categories of QTc interval, and sex and serum concentrations of potassium, calcium, or glucose. Multivariate analyses showed that female sex and hypokalemia were independent risk factors for severe QTc prolongation. Hypokalemia (<3.5 mmol/l) was associated with a relative risk of 4.53 for severe QTc prolongation as compared with normokalemia, while the relative risk associated with female sex was 4.45 as compared with male sex. There was a significant inverse correlation between serum potassium levels and QTc intervals among female patients. CONCLUSION: These findings suggest that female sex and hypokalemia are independent risk factors for severe QTc prolongation in patients with SAH

Complex and continuous change in hypothetic risk of rupture of intracranial cerebral aneurysms – Bleb mandala –

Background: This study of the intraoperative microscopic findings indicated complex behavior of aneurysmal bleb affects the rupture risk. Methods: A total of 300 consecutive relatively small (mean 6.2 mm) unruptured ICAs were clipped from July 2005 to January 2019. Microscopically identified blebs were divided into four types based on external appearances. Type A bleb was a thick-walled bleb. Type B bleb was a thin-walled reddish bleb. Type C bleb was a healing organized bleb. Type D was a hemosiderin-laden bleb. Type B and D blebs were considered to be risky blebs for rupture. ICAs with bleb(s) were further categorized into two types, stable aneurysms and unstable aneurysms with Type B and/or D bleb(s). The number and nature of the blebs were compared with the demographic data of the patients and radiological findings of the ICAs to evaluate possible predictors of the hypothetic rupture risk. Results: Aneurysms tended to enlarge as the number of blebs increased (p = 0.073). High risk Type B bleb had significantly larger number of blebs (p < 0.05). Healing Type C bleb was significantly more common in the group with two blebs than one bleb (p < 0.01). No significant differences were found between stable and unstable aneurysms in aneurysm multiplicity, size, and radiological bleb. Conclusions: Aneurysm state continuously changes due to the dynamic change of bleb number and nature. Our data suggests the necessity of new repeatable vessel-wall imaging technology to select risky unstable ICAs for treatment

Photomechanical wave-driven delivery of siRNAs targeting intermediate filament proteins promotes functional recovery after spinal cord injury in rats.

The formation of glial scars after spinal cord injury (SCI) is one of the factors inhibiting axonal regeneration. Glial scars are mainly composed of reactive astrocytes overexpressing intermediate filament (IF) proteins such as glial fibrillary acidic protein (GFAP) and vimentin. In the current study, we delivered small interfering RNAs (siRNAs) targeting these IF proteins to SCI model rats using photomechanical waves (PMWs), and examined the restoration of motor function in the rats. PMWs are generated by irradiating a light-absorbing material with 532-nm nanosecond laser pulses from a Q-switched Nd:YAG laser. PMWs can site-selectively increase the permeability of the cell membrane for molecular delivery. Rat spinal cord was injured using a weight-drop device and the siRNA(s) solutions were intrathecally injected into the vicinity of the exposed SCI, to which PMWs were applied. We first confirmed the substantial uptake of fluorescence-labeled siRNA by deep glial cells; then we delivered siRNAs targeting GFAP and vimentin into the lesion. The treatment led to a significant improvement in locomotive function from five days post-injury in rats that underwent PMW-mediated siRNA delivery. This was attributable to the moderate silencing of the IF proteins and the subsequent decrease in the cavity area in the injured spinal tissue

Effectiveness of Keyhole Clipping of Unruptured Intracranial Aneurysms Detected by “Brain Dock” in Healthy Japanese Adults

In Japan, brain docking has enhanced the detection of unruptured intracranial aneurysms in healthy adults. At our institution, surgical clipping is the first-line treatment for unruptured intracranial aneurysms (UIA). In this study, the differences in neurological and radiological outcomes, as well as cognitive and psychological results, between standard clipping and keyhole clipping for these aneurysms detected via brain docking were evaluated. The study included 131 aneurysms detected via “brain dock.” Of these, 65 were treated with keyhole clipping surgery (keyhole clipping group), and 66 were treated with standard clipping surgery (standard clipping group). Evaluations at 3 months included the National Institutes of Health Stroke Scale, modified Rankin Scale, Mini-Mental State Examination, Hasegawa's Dementia Scale-revised, Beck Depression Inventory, Hamilton Rating Scale for Depression, and radiological abnormalities. The mean operative time and postoperative hospitalization period were significantly shorter in the keyhole clipping group than in the standard clipping group (p < 0.001). Between the groups, no significant differences in postoperative neurological complications or radiological abnormalities were found. The keyhole clipping group demonstrated slightly but significantly better Beck Depression Inventory and Hamilton Rating Scale for Depression scores than the standard clipping group (Beck Depression Inventory, p = 0.046; Hamilton Rating Scale for Depression, p < 0.01). Both the Beck Depression Inventory and Hamilton Rating Scale for Depression scores at 3 months were significantly enhanced (p < 0.001) in the keyhole clipping group. These findings propose that keyhole clipping could be considered a new therapeutic option for small UIA detected via brain docking