Amy Vickers, Nov 2006

The most frequently suggested reason for the abnormal bossing (expansion) of the Starchild's parietal bones is hydrocephaly.

Description

Hydrocephaly (also called Hydrocephalus [1]) is a condition where abnormal accumulation of cerebrospinal fluid (CSF) in the cranium causes an increase in CSF pressure [2]. This fluid accumulation can occur at any time in life, and has various potential causes including congenital defect, hemorrhage into the brain, infection, meningitis, tumor, or head injury [3]. The CSF can collect inside the tissues of the brain, externally, between the brain and the cranial wall, or both [4]. In infants and children with unfused cranial sutures, the increased internal cranial pressure from hydrocephaly causes the skull to enlarge by forcing the sutures to expand in all directions [5][6] (as shown right). In adults, suture fusion means there is no cranial expansion, thus the pressure is exerted fully on the brain[7].

In addition to standard hydrocephaly, there are two classifications of hydrocephaly that do not result in abnormal CSF pressure: "Hydrocephalus ex vacuo," which occurs as the result of damage to the brain [8], and Normal pressure hydrocephalus, which can occur due to a gradual blockage of the CSF drainage pathways in the brain [9].

Various experts have suggested that the Starchild was hydrocephalic as an infant, causing the abnormal parietal expansion and cranial shape now evident in the skull. However, cranial expansion caused by hydrocephalus results in a widening of the cranial sutures [10] (as shown above), and there is no evidence of this in the Starchild skull. It was examined by respected craniofacial surgeon Dr. Ted Robinson in consultation with ten other specialists [a], who could find no evidence of widening or other abnormality of the cranial sutures [11]. Dr. Bachynsky found no signs of erosion by CSF on the internal surfaces of the skull, and supported Dr. Robinson in his conclusion that the Starchild was not hydrocephalic [12].