Temporal bone encephalocele and cerebrospinal fluid fistula repair utilizing the middle cranial fossa or combined mastoid–middle cranial fossa approach

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The goals of this study were to report the clinical presentation, radiographic findings, operative strategy, and outcomes among patients with temporal bone encephaloceles and cerebrospinal fluid fistulas (CSFFs) and to identify clinical variables associated with surgical outcome.


A retrospective case series including all patients who underwent a middle fossa craniotomy or combined mastoid–middle cranial fossa repair of encephalocele and/or CSFF between 2000 and 2012 was accrued from 2 tertiary academic referral centers.


Eighty-nine consecutive surgeries (86 patients, 59.3% women) were included. The mean age at time of surgery was 52.3 years, and the left side was affected in 53.9% of cases. The mean delay between symptom onset and diagnosis was 35.4 months, and the most common presenting symptoms were hearing loss (92.1%) and persistent ipsilateral otorrhea (73.0%). Few reported a history of intracranial infection (6.7%) or seizures (2.2%).

Thirteen (14.6%) of 89 cases had a history of major head trauma, 23 (25.8%) were associated with chronic ear disease without prior operation, 17 (19.1%) occurred following tympanomastoidectomy, and 1 (1.1%) developed in a patient with a cerebral aqueduct cyst resulting in obstructive hydrocephalus. The remaining 35 cases (39.3%) were considered spontaneous. Among all patients, the mean body mass index (BMI) was 35.3 kg/m2, and 46.4% exhibited empty sella syndrome. Patients with spontaneous lesions were statistically significantly older (p = 0.007) and were more commonly female (p = 0.048) compared with those with nonspontaneous pathology. Additionally, those with spontaneous lesions had a greater BMI than those with nonspontaneous disease (p = 0.102), although this difference did not achieve statistical significance.

Thirty-two surgeries (36.0%) involved a middle fossa craniotomy alone, whereas 57 (64.0%) involved a combined mastoid–middle fossa repair. There were 7 recurrences (7.9%); 2 patients with recurrence developed meningitis. The use of artificial titanium mesh was statistically associated with the development of recurrent CSFF (p = 0.004), postoperative wound infection (p = 0.039), and meningitis (p = 0.014). Also notable, 6 of the 7 cases with recurrence had evidence of intracranial hypertension. When the 11 cases that involved using titanium mesh were excluded, 96.2% of patients whose lesions were reconstructed with an autologous multilayer repair had neither recurrent CSFF nor meningitis at the last follow-up.


Patients with temporal bone encephalocele and CSFF commonly present with persistent otorrhea and conductive hearing loss mimicking chronic middle ear disease, which likely contributes to a delay in diagnosis. There is a high prevalence of obesity among this patient population, which may play a role in the pathogenesis of primary and recurrent disease. A middle fossa craniotomy or a combined mastoid–middle fossa approach incorporating a multilayer autologous tissue technique is a safe and reliable method of repair that may be particularly useful for large or multifocal defects. Defect reconstruction using artificial titanium mesh should generally be avoided given increased risks of recurrence and postoperative meningitis.

Abbreviations used in this paper:BMI = body mass index; CPAP = continuous positive airway pressure; CSFF = cerebrospinal fluid fistula.

Article Information

Address correspondence to: George B. Wanna, M.D., Department of Otolaryngology–Head and Neck Surgery, The Bill Wilkerson Center for Otolaryngology & Communication Sciences, 7209 Medical Center East, South Tower, 1215 21st Ave. S., Nashville, TN 37232-8605. email: george.wanna@vanderbilt.edu.

Please include this information when citing this paper: published online July 26, 2013; DOI: 10.3171/2013.6.JNS13322.

© AANS, except where prohibited by US copyright law.



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    Sagittal (upper) and axial (lower) T2-weighted MR images demonstrating empty sella syndrome, with herniating arachnoid of the suprasellar cistern filling the majority of the sella turcica, resulting in downward compression of the pituitary gland.

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    A–C: Coronal temporal bone CT scans demonstrating a left-sided superior semicircular canal dehiscence (white arrows) in a patient with a tympanic cavity encephalocele. D: Coronal CT scan demonstrating coincident left-sided encephalocele and labyrinthine segment facial nerve dehiscence (black arrow). Note the thin bony covering of the contralateral facial nerve (white arrow) for comparison.

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    A: Following a left-sided mastoidectomy, a large encephalocele (white arrow) can be seen filling the mastoid antrum. B: A small middle fossa craniotomy (black arrow) is centered over the tegmen defect that was identified during mastoidectomy. C: The dura is carefully elevated and a large dehiscence (black arrow) is identified on the middle cranial fossa floor. D: A multilayer repair incorporating fascia and an autologous bone plate (black arrow) is performed. EAC = external auditory canal; M = mastoid; T = tegmen.

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    A and B: Following a right-sided mastoidectomy and middle fossa craniotomy, the dura is elevated, and the temporal lobe is gently retracted, revealing multiple defects involving the tegmen tympani and mastoideum (black arrows). C: After adequate exposure is gained, a large composite graft (black arrow) incorporating fascia, bone plate, and collagen dural substitute is placed over the multiple areas of bony dehiscence. D: Inspection of the tegmen from the mastoid vantage point ensures that all bony defects have been adequately covered and there is no active CSF leak. Finally, bone pâté is placed over the tegmen mastoideum (black arrow) to provide additional reinforcement of the repair. TL = temporal lobe.

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    A: Coronal CT scan of a right temporal bone demonstrating an occult epitympanic encephalocele (white arrow) that was discovered after the patient was diagnosed with a right temporal lobe abscess. B and C: Coronal postcontrast T1-weighted and axial T2-weighted MR images demonstrating a 2.2-cm ring-enhancing lesion (white arrows) in the right inferior temporal lobe, with surrounding vasogenic edema.

  • View in gallery

    Axial CT scans demonstrating sequential right (upper) and left (lower) middle cranial fossa encephalocele repair using a multilayer technique incorporating autologous calvarial bone (black arrows) fixed in place with titanium miniplates and screws to prevent displacement.



Brainard LChen DAAziz KMHillman TA: Association of benign intracranial hypertension and spontaneous encephalocele with cerebrospinal fluid leak. Otol Neurotol 33:162116242012


Brown NEGrundfast KMJabre AMegerian CAO'Malley BW JrRosenberg SI: Diagnosis and management of spontaneous cerebrospinal fluid-middle ear effusion and otorrhea. Laryngoscope 114:8008052004


Byrne RWSmith APRoh DKanner A: Occult middle fossa encephaloceles in patients with temporal lobe epilepsy. World Neurosurg 73:5415462010


Centers for Disease Control and Prevention: Overweight and Obesity: Adult Obesity Facts (http://www.cdc.gov/obesity/data/adult.html) [Accessed June 21 2013]:


Flegal KMCarroll MDOgden CLCurtin LR: Prevalence and trends in obesity among US adults, 1999–2008. JAMA 303:2352412010


Gal TJKerschner JEFutran NDBartels LJFarrior JBRidley MB: Reconstruction after temporal bone resection. Laryngoscope 108:4764811998


Glasscock ME IIIDickins JRJackson CGWiet RJFeenstra L: Surgical management of brain tissue herniation into the middle ear and mastoid. Laryngoscope 89:174317541979


Goddard JCMeyer TNguyen SLambert PR: New considerations in the cause of spontaneous cerebrospinal fluid otorrhea. Otol Neurotol 31:9409452010


Goel A: Multilayer reconstruction of the middle cranial fossa floor. Acta Neurochir (Wien) 138:5845891996


Gubbels SPSelden NRDelashaw JB JrMcMenomey SO: Spontaneous middle fossa encephalocele and cerebrospinal fluid leakage: diagnosis and management. Otol Neurotol 28:113111392007


Gurgel RKPopelka GROghalai JSBlevins NHChang KWJackler RK: Is it valid to calculate the 3-kilohertz threshold by averaging 2 and 4 kilohertz?. Otolaryngol Head Neck Surg 147:1021042012


Hanasono MMSilva ASkoracki RJGidley PWDeMonte FHanna EY: Skull base reconstruction: an updated approach. Plast Reconstr Surg 128:6756862011


House JWBrackmann DE: Facial nerve grading system. Otolaryngol Head Neck Surg 93:1461471985


Jackson CGPappas DG JrManolidis SGlasscock ME IIIVon Doersten PGHampf CR: Brain herniation into the middle ear and mastoid: concepts in diagnosis and surgical management. Am J Otol 18:1982061997


Kari EMattox DE: Transtemporal management of temporal bone encephaloceles and CSF leaks: review of 56 consecutive patients. Acta Otolaryngol 131:3913942011


Li PMLinos EGurgel RKFischbein NJBlevins NH: Evaluating the utility of non-echo-planar diffusion-weighted imaging in the preoperative evaluation of cholesteatoma: a metaanalysis. Laryngoscope 123:124712502013


May JSMikus JLMatthews BLBrowne JD: Spontaneous cerebrospinal fluid otorrhea from defects of the temporal bone: a rare entity?. Am J Otol 16:7657711995


National Institutes of Health: The Practical Guide: Identification Evaluation and Treatment of Overweight and Obesity in Adults (http://www.nhlbi.nih.gov/guidelines/obesity/prctgd_c.pdf) [Accessed June 20 2013]


Raine C: Diagnosis and management of otologic cerebrospinal fluid leak. Otolaryngol Clin North Am 38:583595vii2005


Sanna MFois PRusso AFalcioni M: Management of meningoencephalic herniation of the temporal bone: personal experience and literature review. Laryngoscope 119:157915852009. (Erratum in Laryngoscope 120: 217 2010)


Savva ATaylor MJBeatty CW: Management of cerebrospinal fluid leaks involving the temporal bone: report on 92 patients. Laryngoscope 113:50562003


Scurry WC JrOrt SAPeterson WMSheehan JMIsaacson JE: Idiopathic temporal bone encephaloceles in the obese patient. Otolaryngol Head Neck Surg 136:9619652007


Semaan MTGilpin DAHsu DPWasman JKMegerian CA: Transmastoid extradural-intracranial approach for repair of transtemporal meningoencephalocele: a review of 31 consecutive cases. Laryngoscope 121:176517722011


Silver RIMoonis GSchlosser RJBolger WELoevner LA: Radiographic signs of elevated intracranial pressure in idiopathic cerebrospinal fluid leaks: a possible presentation of idiopathic intracranial hypertension. Am J Rhinol 21:2572612007


Stow NWGordon DHEisenberg R: Technique of temporoparietal fascia flap in ear and lateral skull base surgery. Otol Neurotol 31:9649672010


Stucken EZSelesnick SHBrown KD: The role of obesity in spontaneous temporal bone encephaloceles and CSF leak. Otol Neurotol 33:141214172012


Sugerman HJDeMaria EJFelton WL IIINakatsuka MSismanis A: Increased intra-abdominal pressure and cardiac filling pressures in obesity-associated pseudotumor cerebri. Neurology 49:5075111997


Teknos TNSmith JCDay TANetterville JLBurkey BB: Microvascular free tissue transfer in reconstructing skull base defects: lessons learned. Laryngoscope 112:187118762002


Yuh WTZhu MTaoka TQuets JPMaley JEMuhonen MG: MR imaging of pituitary morphology in idiopathic intracranial hypertension. J Magn Reson Imaging 12:8088132000




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