Cortical damage from Zenker's solution applied to the dura mater.

An experimental and clinical study was undertaken to determine whether Zenker's solution without glacial acetic acid (modified Zenker's solution) applied to the external surface of the dura mater can penetrate to injure the underlying cortex. Adult cats and dogs, the dura of which had an average thickness of 0.2 and 0.25 mm, respectively, were given intravenous Evans blue dye as an indicator of blood-brain barrier breakdown. This was followed by the application of modified Zenker's solution to the dura in a manner identical to the clinical practice. When the animals were killed 1 or 2 hours later, the cortex beneath the dura painted with modified Zenker's solution was stained massively. The thickness of human dura was measured; it varied from 0.22 to 0.28 mm in infants of 3 months or less, 0.27 to 0.42mm in infants 4 months to 12 months of age, and 0.32 to 0.45 mm in children to 1 to 18 years of age. Modified Zenker's solution applied to fresh dura for 3 minutes at autopsy gave visual evidence 1 hour later of penetration to the cortex beneath. In operative procedures for craniosynostosis, 69 patients were treated with modified Zenker's solution; of these, 7 developed seizures in the immediate postoperative period. No seizures occurred among the 39 patients on whom modified Zenker's solution was not used. It is concluded that modified Zenker's solution applied to the dura can damage the cortex beneath.