Lipidomic signature of stroke recurrence after transient ischemic attack

While TIA patients have transient symptoms, they should not be underestimated, as they could have an underlying pathology that may lead to a subsequent stroke: stroke recurrence (SR). Previously, it has been described the involvement of lipids in different vascular diseases. The aim of the current study was to perform a lipidomic analysis to identify differences in the lipidomic profile between patients with SR and patients without. Untargeted lipidomic analysis was performed in plasma samples of 460 consecutive TIA patients recruited < 24 h after the onset of symptoms. 37 (8%) patients suffered SR at 90 days. Lipidomic profiling disclosed 7 lipid species differentially expressed between groups: 5 triacylglycerides (TG), 1 diacylglyceride (DG), and 1 alkenyl-PE (plasmalogen) [specifically, TG(56:1), TG(63:0), TG(58:2), TG(50:5), TG(53:7, DG(38:5)) and PE(P-18:0/18:2)]. 6 of these 7 lipid species belonged to the glycerolipid family and a plasmalogen, pointing to bioenergetics pathways, as well as oxidative stress response. In this context, it was proposed the PE(P-18:0/18:2) as potential biomarker of SR condition.The observed changes in lipid patterns suggest pathophysiological mechanisms associated with lipid droplets metabolism and antioxidant protection that is translated to plasma level as consequence of a more intensive or high-risk ischemic condition related to SR.

A parsimonious score with a free web tool for predicting disability after an ischemic stroke: the Parsifal Score

BACKGROUND

Most of the models to predict prognosis after an ischemic stroke include complex mathematical equations or too many variables, making them difficult to use in the daily clinic. We want to predict disability 3 months after an ischemic stroke in an independent patient not receiving recanalization treatment within the first 24 h, using a minimum set of variables and an easy tool to facilitate its implementation. As a secondary aim, we calculated the capacity of the score to predict an excellent/devastating outcome and mortality.

METHODS

Eight hundred and forty-four patients were evaluated. A multivariable ordinal logistic regression was used to obtain the score. The Modified Rankin Scale (mRS) was used to estimate disability at the third month. The results were replicated in another independent cohort (378 patients). The "polr" function of R was used to perform the regression, stratifying the sample into seven groups with different cutoffs (from mRS 0 to 6).

RESULTS

The Parsifal score was generated with: age, previous mRS, initial NIHSS, glycemia on admission, and dyslipidemia. This score predicts disability with an accuracy of 80-76% (discovery-replication cohorts). It has an AUC of 0.86 in the discovery and replication cohort. The specificity was 90-80% (discovery-replication cohorts); while, the sensitivity was 64-74% (discovery-replication cohorts). The prediction of an excellent or devastating outcome, as well as mortality, obtained good discrimination with AUC > 0.80.

CONCLUSIONS

The Parsifal Score is a model that predicts disability at the third month, with only five variables, with good discrimination and calibration, and being replicated in an independent cohort.

Valproate-induced hyperammonemic encephalopathy

Valproate-induced hyperammonemic encephalopathy (VHE) is an unusual complication characterized by a decreasing level of consciousness, focal neurological deficits, cognitive slowing, vomiting, drowsiness, and lethargy. We have thoroughly reviewed the predisposing factors and their screening, the biochemical and physiopathological mechanisms involved, the different treatments described, and those that are being investigated. Etiopathogenesis is not completely understood, although hyperammonemia has been postulated as the main cause of the clinical syndrome. The increase in serum ammonium level is due to several mechanisms, the most important one appearing to be the inhibition of carbamoylphosphate synthetase-I, the enzyme that begins the urea cycle. Polytherapy with several drugs, such as phenobarbital and topiramate, seems to contribute to hyperammonemia. Hyperammonemia leads to an increase in the glutamine level in the brain, which produces astrocyte swelling and cerebral edema. There are several studies that suggest that treatment with supplements of carnitine can lead to an early favorable clinical response due to the probable carnitine deficiency induced by a valproate (VPA) treatment. Development of the progressive confusional syndrome, associated with an increase in seizure frequency after VPA treatment onset, obliges us to rule out VHE by screening for blood ammonium levels and the existence of urea cycle enzyme deficiency, such as ornithine carbamoyltransferase deficiency. Electroencephalography (EEG) is characterized by signs of severe encephalopathy with continuous generalized slowing, a predominance of theta and delta activity, occasional bursts of frontal intermittent rhythmic delta activity, and triphasic waves. These EEG findings, as well as clinical manifestations and hyperammonemia, tend to normalize after VPA withdrawal.