Severe injury of the head in relation to the development of dementia paralytica is of considerable medicolegal importance. This relation is constantly being discussed in courts of law and before industrial accident boards. In 1822 when Bayle first isolated dementia paralytica as an organic brain disease, trauma was mentioned as a cause. Since that time the rôle of trauma in the production of dementia paralytica runs like a red streak through the history of the disease.
The problem of the relation between head trauma and dementia paralytica may be stated as follows: Granted that dementia paralytica is a syphilitic disease of the brain, what rôle does an injury to the head play in the production of initial symptoms of the disease appearing subsequent to such injury and how long delayed may such symptoms be in order to be ascribed to the trauma? What is the rôle of trauma when symptoms