Abstract
Objectives
The objectives of the study were to describe the clinical presentation, diagnostic process, surgical treatment, and outcome of patients with spontaneous dural defect of temporal bone and to explore the possible contribution of idiopathic intracranial hypertension.
Methods
Medical records of consecutive patients with spontaneous defects of the temporal bone were reviewed. Clinical presentation, diagnostic process, exploration of benign intracranial hypertension, surgical management, and outcome of patients are presented.
Results
Six of the 12 patients presenting with spontaneous cerebrospinal fluid otorrhea were women. Ages ranged from 38 to 76 years. Seven patients presented with meningitis. The location and the extent of the occurring defect were detected by computed tomography in all cases. Radiologic signs of empty sella syndrome, indicator of benign intracranial hypertension, were revealed in 3 cases using magnetic resonance imaging. Six tegmen defects were repaired using a middle fossa approach without recurrence. Four patients received the combined approach. All patients had complete resolution of the cerebrospinal fluid leak, although 2 cases developed adverse effects attributable to surgical procedure.
Conclusion
The diagnosis of spontaneous cerebrospinal fluid otorrhea requires clinical suspicion in the setting of meningitis and persistent serous otitis media. High-resolution computed tomography can confirm the diagnosis. The authors’ findings advocate the multilayered closure technique through a middle fossa approach.
1
Introduction
The defects of the temporal bone and the resultant leak of cerebrospinal fluid (CSF) into the middle ear are classified according to their causative factor as either secondary or spontaneous. Secondary defects occur after temporal bone trauma, surgery (iatrogenic), or neoplastic invasion of the skull base . Less commonly, these fissures appear spontaneously without any preceding history of temporal bone disease.
Considering the spontaneous defects of the temporal bone, 2 distinct populations of patients can be described based on the localization and the origin of the occurring fistulas. Firstly, children with congenital abnormal transcranial pathways, such as Mondini dysplasia, dehiscent foot plate, tympanomeningeal fistula, or patent fallopian canal, usually present meningitis after acute or serous otitis media (SOM) . In the second group, middle-aged adults without an explainable congenital or acquired malformation of temporal bone are included .
Except for congenital theory, the hypothesis of the pressure effect of ectopic arachnoid granulations has been postulated as a possible etiopathogenic factor of the adult spontaneous defects of the temporal bone . According to this late hypothesis, risk cofactors to the eroding attribute of ectopic arachnoid granulations to the temporal bone are age, physical activity, and increased intracranial pressure . In 2003, Schlosser and Bolger suggested the strong association between the spontaneous CSF leak and the radiographic empty sella, an indicator of elevated intracranial pressure. The relationship between empty sella syndrome and the spontaneous defects of temporal bone, leading to CSF otorrhea, has recently been confirmed in a study of Prichard et al .
The aim of our study was to describe the clinical presentation, diagnostic process, surgical treatment, and outcome of patients with spontaneous dural defect of temporal bone treated in our department. An additional purpose was to explore the possible contribution of idiopathic intracranial hypertension (ICHT) to the etiopathogenic mechanism of the spontaneous defects of the temporal bone.
2
Material and methods
Retrospective review of medical records of all patients treated in the ENT and Head-Neck Surgery Department of CHU of Bordeaux for spontaneous dural defect of the temporal bone has been performed for the period from June 1996 through June 2008. The Pellegrin University Hospital Institutional Review Board documentation was submitted and approved for this retrospective study. Patients with the following history were excluded:(1) head injury, (2) chronic inflammatory pathology such as chronic otitis, and (3) middle ear or skull base surgery. The review identified 12 patients with spontaneous defect among the 91 patients with dehiscence of temporal bone.
Clinical presentation of cases, diagnostic process, and patient’s potential ICHT were analyzed. The number and the anatomical localization of the defects were assessed by imaging techniques, such as computed tomography (CT) and/or magnetic resonance imaging (MRI). Effectiveness of the performed surgical treatment was evaluated on the basis of the frequency and the severity of recurrences and complications.
2
Material and methods
Retrospective review of medical records of all patients treated in the ENT and Head-Neck Surgery Department of CHU of Bordeaux for spontaneous dural defect of the temporal bone has been performed for the period from June 1996 through June 2008. The Pellegrin University Hospital Institutional Review Board documentation was submitted and approved for this retrospective study. Patients with the following history were excluded:(1) head injury, (2) chronic inflammatory pathology such as chronic otitis, and (3) middle ear or skull base surgery. The review identified 12 patients with spontaneous defect among the 91 patients with dehiscence of temporal bone.
Clinical presentation of cases, diagnostic process, and patient’s potential ICHT were analyzed. The number and the anatomical localization of the defects were assessed by imaging techniques, such as computed tomography (CT) and/or magnetic resonance imaging (MRI). Effectiveness of the performed surgical treatment was evaluated on the basis of the frequency and the severity of recurrences and complications.
3
Results
General epidemiologic data, clinical history, and localization of defects of the 12 patients are presented in Table 1 . Six of our cases were women. The mean age of the patients was 55.4 years, ranging from 38 to 76 years. Four patients presented a left temporal defect, whereas 5 had a defect on the right side; and bilateral dehiscence appeared in 3 patients. In 7 of the 12 patients, meningitis was the major initial clinical presentation. In 2 patients, the disease was diagnosed after a CSF leak, occurring after paracentesis for suspicion of SOM. An intermittent rhinorrhea was the main clinical symptom in 2 patients, presenting as the single sign in one case and being accompanied by otorrhea in the other one. In one patient, the diagnosis was made after the identification of the presence of a retrotympanic mass.
| Patient | Age | Sex | Clinical presentation | Side | Imaging | ICHT signs |
|---|---|---|---|---|---|---|
| 1 | 57 | F | Meningitis | R | CT-MRI | No |
| 2 | 53 | F | Hypoacousis | Bilateral | CT | Yes |
| 3 | 67 | F | Hypoacousis | Bilateral | CT-MRI | No |
| 4 | 76 | M | Rhinorrhea, SOM | R | CT-MRI | No |
| 5 | 62 | M | Otorrhea | L | CT | No |
| 6 | 71 | M | Rhinorrhea, meningitis | R | CT | No |
| 8 | 43 | F | Meningitis | L | CT-MRI | Yes |
| 7 | 53 | M | SOM, otorrhea | R | CT | No |
| 9 | 43 | F | Meningitis | L | CT-MRI | Yes |
| 10 | 38 | F | SOM, meningitis | R | CT-MRI | No |
| 11 | 60 | M | SOM, meningitis | Bilateral | CT-MRI | No |
| 12 | 42 | M | Meningitis | L | CT-MRI | No |
A diagnostic CT imaging was performed in all patients, with 6 of them receiving a high-resolution scan. In all cases, the CT scan revealed the precise diagnosis and the localization of the fissure ( Table 1 ). In those cases (7 patients) where a meningoencephalocele was suspected, an MRI scan was performed, allowing the determination of the nature of the tissue in the middle ear. Based on the findings of MRI, the possibility of occurrence of the ICHT syndrome (empty sella turcica, cerebral ventricular dilatation) was evaluated.
The tegmen tympani was the most common site involved in our study, either alone (9 patients) or in combination with a fissure in tegmen mastoideum (3 patients) ( Table 2 ). Patient 9 was found to have a fissure adjacent to a bony erosion of the geniculate fossa ( Fig. 1 ). Case 3 was 1 of the 4 cases in which a meningoencephalocele was identified, fulfilling almost the entire tympanic cavity ( Fig. 2 ). Tegmen tympani defect and superior semicircular canal dehiscence in both temporal bones appeared in case 11 ( Fig. 3 ). Concerning the type of fissure, 7 of 12 patients had single bony dehiscence (punctiform or not), whereas 3 cases presented bilateral defects and 2 patients had multiple erosions.
