The safety and efficacy of levetiracetam versus phenytoin for seizure prophylaxis after traumatic brain injury: A systematic review and meta-analysis.

BACKGROUND: The standard for early traumatic brain injury (TBI) seizure prophylaxis is phenytoin (PHT). Levetiracetam (LEV) has been proposed as an alternative to PHT. The aim of this study was to evaluate the safety and efficacy of LEV on TBI seizure when compared with PHT. METHODS: A search was carried out based on the databases from Pubmed, Embase and the Cochrane database up to May 2015. The relative risk (RR) and the relevant 95% confidence intervals (CI) were determined. RESULTS: Eight observational studies and one randomized controlled trial involving 2035 cases were included. The results indicated that no significant differences in terms of overall seizure (RR = 0.90; 95% CI = 0.51-1.53; p = 0.68), early seizure (RR = 1.06; 95% CI = 0.37-3.07; p = 0.92) and late seizure (RR = 1.10; 95% CI = 0.43-2.79; p = 0.85) occurrence. However, LEV was associated with a lower adverse drug reaction rate (RR = 0.43; 95% CI = 0.23-0.81; p = 0.01). Moreover, there were no significant differences in terms of mortality, length of ICU or hospital stay between groups. CONCLUSIONS: The meta-analysis suggests that LEV appears to have a similar efficacy to PHT on TBI. A better safety profile of LEV is supported by this analysis.

Specific knockdown of hippocampal astroglial EphB2 improves synaptic function via inhibition of D-serine secretion in APP/PS1 mice.

Increasing evidence emphasizes the protective role of Eph receptors in synaptic function in the pathological development of Alzheimer's disease (AD); however, their roles in the regulation of hippocampal astrocytes remain largely unknown. Here, we directly investigated the function of astroglial EphB2 on synaptic plasticity in APP/PS1 mice. Using cell isolation and transgene technologies, we first isolated hippocampal astrocytes and evaluated the expression levels of ephrinB ligands and EphB receptors. Then, we stereotaxically injected EphB2-Flox-AAV into the hippocampus of GFAP-cre/APP/PS1 mice and further evaluated hippocampal synaptic plasticity and astroglial function. Interestingly, astrocytic EphB2 expression was significantly increased in APP/PS1 mice in contrast to its expression profile in neurons. Moreover, depressing this astroglial EphB2 upregulation enhanced hippocampal synaptic plasticity, which results from harmful D-serine release. These results provide evidence of the different expression profiles and function of EphB2 between astrocytes and neurons in AD pathology.