To the Editor.
—We We were interested to read the article by Weiss et al (Archives 1983;40:7-10) on the use of mathematic formulas to predict post-traumatic epilepsy (PTE) after missile-induced head trauma. However, missile wounds are not common among civilians with head injuries. As for closed head trauma, many studies have been performed to define the factors that may allow us to predict the risk of PTE at the time of head trauma itself. Factors generally accepted to increase significantly the risk of PTE are loss of consciousness for more than 24 hours, focal neurologic signs, early seizures, depressed skull fracture, intracranial hematoma, and dural lacerations.1-3 The risk is higher when two or more of these factors are associated.4 As for clinical risk factors (ie, loss of consciousness for more than 24 hours, focal neurologic signs, early seizures, and depressed skull fracture), the main problem is whether the