A 45-year-old man presented with nausea and new-onset headache. He had a history of congenital obstructive hydrocephalus due to Chiari II malformation, treated during infancy with a ventriculoperitoneal shunt. CT scan of head confirmed ventricular enlargement from shunt failure. Following shunt replacement, his symptoms resolved. MR scan of brain after the procedure showed that the ventricles had reduced in size, but there was an extensive callosal lesion, without diffusion restriction or contrast enhancement. The patient remained asymptomatic. Repeat MR scan of brain 2 weeks later showed the callosal abnormality had completely resolved (figure 1). We diagnosed corpus callosum impingement syndrome based on the imaging findings and history of a recent ventricular decompression.
Corpus callosum impingement syndrome is a rare complication of ventricular shunting for severe hydrocephalus. It is caused by impingement of the corpus callosum against the inferior border of the cerebral falx.1 2<cross-ref type="bib"…