Interaction of excitatory amino acid agonists with cortical afterdischarges in developing rats

Association between methylenetetrahydrofolate reductase C677T polymorphism and epilepsy susceptibility: a meta-analysis

PURPOSE

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism has been implicated as a potential risk factor for epilepsy. To date, many case-control studies have investigated the association between MTHFR C677T polymorphism and epilepsy susceptibility. However, those findings were inconsistent. The objective of this study is to evaluate the precise association between MTHFR C677T polymorphism and epilepsy.

METHODS

An electronic search of PubMed, EMBASE for papers on the MTHFR C677T polymorphism and epilepsy susceptibility was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association.

RESULTS

Ten case-control studies containing 1713 cases and 1867 controls regarding MTHFR C677T polymorphism were selected. A significant association between the MTHFR C677T polymorphism and epilepsy susceptibility was revealed in this meta-analysis (for T vs. C: OR=1.19, 95% CI=1.08-1.32; for TT+CT vs. CC: OR=1.20, 95% CI=1.05-1.38; for TT vs. CC: OR=1.48, 95% CI=1.20-1.83; for TT vs. CT+CC: OR=1.35, 95% CI=1.12-1.64). In subgroup analysis by ethnicity, the results also indicated the association between the MTHFR C677T polymorphism and epilepsy susceptibility within the Asian populations (for T vs. C: OR=1.55, 95% CI=1.15-2.07; for TT+CT vs. CC: OR=1.67, 95% CI=1.08-2.59; for TT vs. CC: OR=2.33, 95% CI=1.30-4.20; for TT vs. CT+CC: OR=1.89, 95% CI=1.12-3.18).

CONCLUSION

The results indicated that MTHFR C677T polymorphism was associated with an increased risk of epilepsy. However, further studies in various regions are needed to confirm the findings from this meta-analysis.

Two types of seizures in homocysteine thiolactone-treated adult rats, behavioral and electroencephalographic study

D,L-homocysteine thiolactone (H), a reactive homocysteine metabolite, contributes to total homocysteine pool. The aim of the present study was to determine the effects of H after acute application in increasing doses to rats. Adult Wistar rat were intraperitoneally administered saline or H in increasing doses (5.5, 8.0, or 11.0 mmol/kg). For electroencephalographic (EEG) recordings, three gold-plated screws were implanted into the skull and animals were supervised. We observed H-induced two types of seizures, the coexistence of convulsive and nonconvulsive epilepsy. Dose-related increase in the number and severity (0-4) of displaying convulsions was recorded. In H(5.5) group, the majority of seizure episodes were grade 1 (62.5 and 0% lethality), in H(8) 40% grade 2, and in H(11) grade 4 in 42.11% (100% lethal outcome). EEGs recordings in convulsive animals showed a high-voltage spike-wave and polyspikes complexes. The second, absence-like, nonconvulsive seizures were accompanied by the EEGs mostly with 6-8 Hz spikes-and-wave discharges (SWD). Latency time to the generalized clonic-tonic seizures overlapped with the time of the maximal median number and median duration of the SWD per 15 min during 90-min observing period. The results show that acute H administration significantly changes neurons, EEG tracings, and behavioral responses and suggests a possible model for studying petit mal epilepsy.