HYDROCEPHALUS AND ACHONDROPLASIA - A STUDY OF 25 OBSERVATIONS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 7  (4) , 205-219
Abstract
The following 2 series of achondroplastic patients were studied: 5 patients referred for macrocranium and/or mental retardation, and 20 patients arbitrarily chosen from a medical group. Macrocranium was observed in 60% of the patients and was related to hydrocephalus in all but 2 cases. Radiologically, the posterior fossa was deformed and narrowed in its 3 planes; its volume was conserved because of an abnormal ascension of the tentorium. The conflict between normal brain development and the craniostenosis at the base of the skull is responsible for an upward tilt of the petrous pyramids, a lowering of the mastoid process and the illusion of a basilar invagination. Ventriculographies, pneumoencephalographies and isotopic transits demonstrated normal CSF circulation. Hydrocephalus apparently is related to the stenosis of the sigmoid sinus at the level of narrowed jugular foramina with a resulting raise in intracranial venous pressure. The majority of patients with macrocranium stabilizes spontaneously. A surgical indication should be extremely limited.