[The unusual origin of an acute cephalalgia, a colloid cyst of the third ventricle (author's transl)].

An unusual acute cephalalgia might reveal a vascular or tumoral cerebral disease. The authors report a case of cephalalgia of such a type following upon a colloid cyst of the third ventricle, an exceptional but serious cause, whose symptomatology they are discussing; in this connection, they are studying the problems concerning three other cases of acute cephalalgia. In these four patients, cephalalgia is almost the only symptom. A recent unique relapsing acute cephalalgia, without appreciable previous history, should induce to perform thorough paraclinical investigations and, above all at present, a tomodensitometric test.