Hydrocephalus which appears not to originate within the brain, is described as external hydrocephalus. Normal Pressure Hydrocephalus (NPH) because nowhere in the head has raised pressure been found. Nevertheless, it produces abnormal skull growth (macrocephaly) and
other abnormalities typical of other forms of hydrocephalus. There appears to be some genetic factor involved. The interventricular foramina and the cerebral aqueduct are physically vulnerable to closure, blocking flow and causing pressure to build in ventricles upstream. This all occurs within the brain and the resultant forms of hydrocephalus are classed as internal hydrocephalus. Recently it has been proposed that external hydrocephalus is actually produced by pressure like other forms of hydrocephalus, but that the pressure is transient, Transient Venous Hypertension Hydrocephalus (TVHH) . It is produced when blood is forced retrograde up the SVC into the cerebral vasculature by high intra-abdominal pressures during vomiting and retching or paroxysmal coughing.
David G Talbert, Is âShaken Baby Syndromeâ The Malignant Peak of a âBenign
Hydrocephalus of Infancyâ Iceberg?
Last date updated on June, 2014