Hyrtl fissure

Last revised by Daniel J Bell on 4 Jun 2020

Hyrtl fissure (also known as tympanomeningeal fissure) is a congenital infralabyrinthic fissure through the petrous temporal bone. It is a very rare cause of spontaneous CSF otorrhea and meningitis.

This fissure is present in the developing fetal petrous temporal bone and is typically ossified by 24 weeks.

  • the fissure can be seen on thin axial slices and coronal reformations
  • CT cisternography can also help diagnose this rare condition
  • heavily T2 weighted images are helpful

Once the diagnosis is established, attempts to surgically close the fissure can be planned 1.

Hyrtl described his eponymous fissure in 1936 1.

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.