The epileptic attack has been attributed to various and even opposite influences, thus to both cerebral anemia and cerebral hypermia, local or general, to both increase and diminution in intracranial pressure, to accumulation and discharge of nervous energy, but no one explanation is entirely sufficient or satisfactory for all cases. Sometimes the one, sometimes the other influence appears to be effective or at least provocative. Having observed in two cases of traumatic porencephaly with epileptic convulsions that long-continued drainage of the lateral ventricle, which communicated with the porencephalic cyst, was attended with a cessation of the attacks, and a like result in a case of traumatic epilepsy. Koche<sup>1</sup>concluded that the increased pressure of the cerebrospinal fluid was of considerable influence in exciting the convulsive seizures, the drainage acting as a regulator for sudden variations in pressure. Similar observations have been made by others, and Stadelmann<sup>2</sup>by means