Multiple skull base defects in the setting of spontaneous cerebrospinal fluid rhinorrhea; a dual institution view

Am J Otolaryngol. 2024 Jan-Feb;45(1):104048. doi: 10.1016/j.amjoto.2023.104048. Epub 2023 Sep 22.


Purpose: Idiopathic intracranial hypertension (IIH) is a condition of high cerebrospinal fluid (CSF) pressure that presents with CSF leak. The implications of multiple skull base defects (SBD) and associated synchronous CSF leaks have not been previously explored.

Materials and methods: A dual institutional case-control study examined multiple SBD's and encephaloceles on the risk of CSF leak and postoperative failures post-repair. IIH patients with CSF leaks and IIH controls without leaks were selected retrospectively. Chi square analysis evaluated for statistically significant alterations in probability with CSF leak development.

Results: 192 patients were selected with 108 IIH controls and 84 spontaneous CSF leak cases. Signs and symptoms for IIH controls and CSF leak cases respectively were pulsatile tinnitus (60.2 % and 29.8 %), headaches (96.3 % and 63.1 %), papilledema (74.1 % and 12.5 %), visual field defects (60.8 % and 13 %) (p < 0.001). Encephalocele formation in controls was 3.7 % compared to cases at 91.6 % (p < 0.001). Multiple SBD's in controls compared cases was 0.9 % and 46.4 % respectively (p < 0.001). Subgroup analysis of CSF leak cases showed 15 patients with two CSF leak repairs due to a recurrence. 27 (39.1 %) single leak cases had multiple SDB's while 12 (80 %) recurrent leaks had multiple SDB's (p = 0.004).

Conclusions: Patients with radiographic evidence of multiple SBD's and encephaloceles represent a high-risk population with a propensity for CSF leaks. Secondary SBD's are common in patients with spontaneous CSF rhinorrhea and higher in patients with a recurrence.

Keywords: Encephalocele; Idiopathic intracranial hypertension; Skull base dehiscence; Spontaneous CSF leak; Transverse sinus stenosis stenting.

MeSH terms

  • Case-Control Studies
  • Cerebrospinal Fluid Leak / diagnosis
  • Cerebrospinal Fluid Leak / epidemiology
  • Cerebrospinal Fluid Rhinorrhea* / etiology
  • Cerebrospinal Fluid Rhinorrhea* / surgery
  • Encephalocele / complications
  • Encephalocele / surgery
  • Humans
  • Intracranial Hypertension*
  • Neoplasm Recurrence, Local
  • Retrospective Studies
  • Skull Base / diagnostic imaging
  • Skull Base / surgery
  • Treatment Outcome