Endothelin in Status Epilepticus
Abstract number :
2.133
Submission category :
Year :
2001
Submission ID :
907
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
E. Tayag, MD, Neurology, USC, Los Angeles, CA; A. Jeng, PhD, Novartis Inst. Biomed. Res, Summit, NJ; P. Savage, MS, Novartis Inst. Biomed. Res, Summit, NJ; P. Gott, PhD, Neurology, USC, Los Angeles, CA; C. DeGiorgio, MD, Neurology, UCLA, Los Angeles, CA;
RATIONALE: Endothelin (ET) is a peptide that is found throughout the body including brain. ET has many functions including being a potent vasoconstrictor as well as having neurotransmitter action in the brain. ET has been demonstrated to lead to efflux of cellular calcium, release of intracellular stored calcium, activation of phospholipase C, and inhibition of Na/K ATPase. ET has three isoforms ET-1, ET-2, and ET-3. The role of ET in the brain is not well known with only sparse literature, some which suggest ET-1 is pro-convulsant and another study suggesting ET-3 has an anticonvulsant effect in animals. There has only been one study of ET-1 in seizures in rats induced by bicucline demonstrating elevated ET-1. ET levels in human seizures has not been measured.
METHODS: Serum samples from some of the patients (n = 89) who participated in the DVA Cooperative Study, [dsquote]A comparison of four treatments for generalized convulsive status epilepticus[dsquote] ([italic]NEJM [/italic]339:792-798, 1998) were randomly selected and analyzed for ET. A group of 15 healthy subjects without epilepsy served as a control group. The patients with status epilepticus may have had up to 4 blood samples each and the peak ET was used. The ET was measured in a blinded fashion to the classification of overt vs subtle status.
RESULTS: The peak ET levels for the patients with status epilepticus had a mean of 1.35 pg/ml vs 0.31 pg/ml for the controls which on Wilcoxon 2 sample test had a T-Test approx significance = 0.0001. The breakdown of the status group between overt (n=84) and subtle (n=5) showed no difference in peak ET. There was also no change of ET levels over the 12 hour sampling period, although the 12 hour sampling period was highly variable for the duration of seizure at the time of entry into the study.
CONCLUSIONS: ET levels appeared to be elevated in status epilepticus compared to controls. The significance of ET elevation is not known. The serum samples were old when the ET was measured in status patients as opposed to control samples, which may be a confounding variable. Further prospective studies with baseline ET levels as well measurement of the three isoforms before seizures where the patients act as their own controls may be more informative.