Paramethadione is an anticonvulsant in the oxazolidinedione class. It is associated with fetal trimethadione syndrome, which is also known as paramethadione syndrome. (en)
# Hoffman DJ, Chun AH: Paramethadione and metabolite serum levels in humans after a single oral paramethadione dose. J Pharm Sci. 1975 Oct;64(10):1702-3. "Pubmed":http://www.ncbi.nlm.nih.gov/pubmed/1185541 # Feldman GL, Weaver DD, Lovrien EW: The fetal trimethadione syndrome: report of an additional family and further delineation of this syndrome. Am J Dis Child. 1977 Dec;131(12):1389-92. "Pubmed":http://www.ncbi.nlm.nih.gov/pubmed/412416 (en)
Dione anticonvulsants such as paramethadione reduce T-type calcium currents in thalamic neurons (including thalamic relay neurons). This inhibits corticothalamic transmission and raises the threshold for repetitive activity in the thalamus. This results in a dampening of the abnormal thalamocortical rhythmicity proposed to underlie the 3-Hz spike-and-wave discharge seen on electroencephalogram (EEG) during absence seizures. (en)