Cerebrospinal fluid (CSF) leaks in the temporal bone arise from osteodural defects, resulting in an abnormal connection between the subarachnoid space and the adjacent tympanomastoid cavity, which often manifests as otorrhea. Patients typically exhibit symptoms such as headache, unilateral hearing impairment, aural fullness, or even meningitis. Imaging studies are critical for identifying and differentiating the location and characteristics of CSF leaks. However, when the leak's origin remains ambiguous, diagnostic surgery may be warranted to both confirm the diagnosis and facilitate treatment. This report discusses an uncommon case while reviewing relevant literature, focusing on the surgical diagnostic intervention in a 58-year-old male with spontaneous temporal bone CSF leaks.

The patient, a 58-year-old man, was admitted for evaluation of left ear fullness, hearing loss, and nasal discharge. Notably, when supine, clear fluid drained from the left nasal cavity, with improvement noted upon sitting. A nasal examination did not reveal significant findings, while the otologic evaluation indicated an intact periosteum; however, considerable fluid accumulation was identified within the left middle ear. Despite undergoing multiple periosteal punctures and conservative medical management, the middle ear effusion persisted. Imaging studies, including magnetic resonance imaging (MRI) and computed tomography, confirmed the presence of left-sided CSF otorrhea, and the head MRI indicated potential CSF rhinorrhea. This raised challenges in determining whether the CSF leak originated from the sphenoid sinus or the temporal bone. Given that CSF otorrhea may drain through the external auditory canal and CSF rhinorrhea from the sellar region can present as nasal leakage, differentiation proved complex. In this case, with an intact external auditory canal, CSF from the middle ear was observed to flow into the nasal cavity via the Eustachian tube. Therefore, leakage from both sites could be misconstrued as CSF rhinorrhea, complicating the diagnostic process. Consequently, an exploratory surgical procedure was performed, revealing an incomplete dura mater on the temporal aspect of the petrous bone, which was subsequently repaired.

Benign intracranial hypertension can result in meningeal protrusion or meningoencephalocele, which may lead to CSF leakage that generally responds favorably to mucosal repair. In instances where imaging fails to identify the source of the leak or when diagnostic options are limited, proactive exploratory surgery is advisable. Although surgical interventions carry inherent risks, the application of endoscopic techniques by experienced surgeons renders this approach a feasible choice for addressing both diagnostic and therapeutic challenges.

• Spontaneous temporal bone cerebrospinal fluid leaks
• Diagnosis
• Exploratory operation
• Endoscopic
• Case report

• CSF leak
• CSF otorrhea
• CSF rhinorrhea
• Computed tomography cisternography
• Gadolinium-enhanced magnetic resonance cisternography
• Idiopathic intercranial hypertension
• Intrathecal contrast medium

• Humans
• Contrast Media/administration & dosage
• Cerebrospinal Fluid Leak/diagnostic imaging
• Cerebrospinal Fluid Leak/etiology
• Tomography, X-Ray Computed/methods
• Magnetic Resonance Imaging/methods
• Skull Base/diagnostic imaging
• Myelography/methods
• Cerebrospinal Fluid Rhinorrhea/diagnostic imaging
• Injections, Spinal/methods

• Spontaneous cerebrospinal fluid leak (sCSFL)
• case report
• increased intracranial pressure (ICP)
• multiple cerebrospinal fluid leaks

• CSF leak
• CSF otorrhea
• CSF rhinorrhea
• Cisternography
• Idiopathic intercranial hypertension

• Cerebrospinal Fluid Leak/diagnostic imaging
• Cerebrospinal Fluid Leak/etiology
• Cerebrospinal Fluid Rhinorrhea/diagnostic imaging
• Cerebrospinal Fluid Rhinorrhea/etiology
• Humans
• Magnetic Resonance Imaging
• Skull Base/diagnostic imaging
• Tomography, X-Ray Computed

Cerebrospinal fluid (CSF) leak remains a rare condition, characterized by serious complications and potentially fatal. According to different etiologies, CSF leaks may be classified into two main categories: traumatic and spontaneous. Spontaneous fistulas seem to be mainly related to obesity and idiopathic intracranial hypertension. Diagnosis is both clinical and radiological. During the last three decades, surgical treatment has mostly shifted to endonasal endoscopic approach, which widely demonstrated to be more effective than invasive intracranial ones. Post-operative complications, long-term sequelae and hospital stay are strongly reduced thanks to endoscopic approach. The diagnosis and treatment of CSF leaks represent a difficult and challenge task. The main effort seems to be related to the precise localization of the leak. An accurate assessment of both predisposing factors and comorbidities is mandatory in case of spontaneous leaks. However, a clinical multidisciplinary evaluation as well as treatment, is essential to decrease the rate of failure of surgery. The presence of a dedicated instruments, the Skull Base Team, the knowledge of reconstructive materials and techniques represents a decisive result in therapeutical management even if for each patient an effective therapeutic algorithm can be obtained considering the correct leak detection and characteristics. In conclusion the strict teamwork with neurosurgeons, neuroradiologists, ophtalmologists will enable the development also of innovative biomaterials, which could spread and standardize multi-layer techniques, nowadays still related to surgeon preferences.

• CSF leak
• endoscopic skull base surgery
• rhinoliquorrea