[Transitory headaches caused by a colloid cyst of the third ventricle].

A 34-year-old man had a history of short-lasting episodes of rotatory vertigo followed by severe headache, provoked by sudden movements of the head and body. MRI of the brain revealed hydrocephalus secondary to a colloid cyst at the level of the foramen of Monro. The patient underwent microsurgery, after which he remained without symptoms. Colloid cysts are rare, benign tumours accounting for 0.5-1.0% of all primary brain tumours. They are attached by a stalklike appendage to the roof of the third ventricle between the fornices. Typical symptoms include intermittent headache, vomiting, occasional dizziness and blurred vision. These symptoms may be secondary to intermittent obstruction of cerebrospinal-fluid outflow through the foramen of Monro. The results of clinical and neurological examination are usually normal. In any patient with short-lasting episodes of severe headache, provoked by changes in position, an MRI of the brain should be done to exclude a colloid cyst. In general, these patients do not fulfil the criteria of the International Headache Society for migraine because of the short-lasting nature of the pain.