The false fontanel.

In the neonate, palpation of the anterior fontanel is recognized as a simple and reliable means for estimating intracranial pressure. With closure of the fontanel this aspect of the clinical examination is lost. The authors report a series of 15 shunted infants and children in whom a false fontanel was created by making a 2-cm craniectomy in the right parietal region and excising the underlying internal pericranium. This produces a cranial opening which, like the anterior fontanel, can be used for palpation and real-time ultrasound imaging of the brain. By removing the internal pericranium, reossification of the defect is delayed by more than 12 months. Sparing the dura propria avoids the risks of cerebrospinal fluid leak or brain herniation into the cranial window. This procedure is reported to be simple, reliable, and of value in assessing shunt function in hydrocephalic infants and young children. An illustrative case report is presented.