An animal model of corpus callosum impingement as seen in patients with normal pressure hydrocephalus

Rationale and Objectives: Callosal impingement has been postulated to cause the symptoms associated with normal pressure hydrocephalus. The authors developed an animal model for the investigation of corpus callosum impingement by the falx cerebriMETHODS.The corpus callosum was compressed from above by a plastic blade and surgically placed in the interhemispheric fissure in adult Sprague-Dawley rats. Magnetic resonance imaging (MRI) was performed both preoperatively and postoperatively. The brains of the rats also were examined grossly at the time of autopsy. Results: All rats survived the surgical procedure. MRI proved to be a suitable method to image the corpus callosum, to confirm the location of the blade, and to demonstrate the corpus callosum impingement. MRI correlated well with necroscopy sections. Conclusions: It was possible to surgically produce callosal impingement in rats, and this impingement could be confirmed by MRI. In the future, this rat model of callosal impingement will be used to search for evidence of changes in metabolism, neuroelectrical activity, behavior, and neuronal anatomy which are known or are thought to be associated with hydrocephalus.