cerebrospinal fluid ( csf ) otorrhea most commonly occurs as a result of trauma , surgery , or congenital anomalies . although spontaneous csf otorrhea is a rare condition , it is life - threatening because of the high incidence of subsequent meningitis . immediate and definitive repair of a csf leak is important to prevent this potential complication . surgical approaches include a transmastoid approach , middle fossa craniotomy , or a combined approach . we recently experienced the case of a patient with spontaneous csf otorrhea occurring through a bony defect in the anterior wall and roof of the epitympanum . a 49-year - old woman was referred to our hospital because of right pulsatile otorrhea after myringotomy . when a local otolaryngologist examined her ear , there was visible fluid through the tympanic membrane . thus , she was diagnosed as right serous otitis media and treated with antibiotics . however , the fluid remained despite a 2-week treatment . myringotomy was attempted but failed due to profuse pulsatile clear discharge from the myringotomy site . the pure tone audiogram of the right ear revealed conductive hearing loss of 40 db ( air - bone gap 32 db ) . her body weight was 70 kg and body mass index was 27.7 kg / m . high resolution computed tomography ( hrct ) scan and magnetic resonance imaging ( mri ) of temporal bone were performed for further evaluation of the otorrhea . the hrct scan revealed a large , bony , anteromedial defect from the anterior wall to the roof of the right epitympanum ( fig . t2 weighted mri demonstrated high signal intensity in right middle ear and mastoid cavity , consistent with csf ( fig . on entering the antrum , a profuse clear discharge from epitympanum was noted . to further evaluate the tegmen tympani , an approximately 8 mm bony defect was apparent from the anterior roof of the epitympanum extending to the anterior wall . there was no identifiable any healthy dura or brain tissue herniation along with the csf leak site . after that , large piece of bone chip was inserted into the defect to cover the fascia . other bone chips were placed in the defect , unless there was no evidence of the csf leak . a postoperative ct scan demonstrated that the defect had sealed and revealed a pneumocephalus in the right temporal lobe ( fig . spontaneous csf otorrhea is defined when there are no identifiable causes such as past history of trauma , surgery , infection or tumor.1 ) the origin of the csf leak is commonly a defect in the tegmen of the middle cranial fossa , less in posterior fossa . the pathophysiology of spontaneous csf otorrhea is not entirely clear . the first is the congenital defect theory , which posits that tiny defects within the tegmen caused by aberrant embryologic development enlarge over time secondary to constant csf pressure . this enlargement leads to eventual dural herniation and subsequent bony and dural thinning with resultant csf otorrhea.2 ) the arachnoid granulation theory postulates that arachnoid granulations that do not find a venous termination during embryonic development come to lie in a blind - end against the inner bony surface of the skull.3 ) these granulations enlarge with age and may eventually erode bone . aberrant arachnoid granulations located in the dural surface of the temporal bone are thought to be responsible for communication between the csf space and the mastoid air cell system . gacek3 ) identified an 8.5% incidence of arachnoid granulations in the posterior fossa of the temporal bone , while ferguson , et al.4 ) observed an incidence of 22% of pit holes created by arachnoid granulations in the middle fossa surface . recent clinical studies have drawn attention to demographic features of patients with spontaneous csf otorrhea as potential clues to the cause . these include age , low grade inflammation , and increased intracranial pressure ( icp).2 ) females are affected more often than males.5 ) middle - aged and obese ( body mass index > 30 kg / m ) persons are more apt to develop spontaneous csf otorrhea.6,7 ) schlosser , et al.8 ) reported increased icp and idiopathic intracranial hypertension as common findings among patients of spontaneous csf otorrhea and suggested that obesity and increased bmi may play a role . bone defect of cranial fossa can be closed using a variety of autologous materials , such as fascia , fat , muscle , cartilage , and bone , or synthetic materials including silicone , silastic , marlex , hydroxyapatite cement , and titanium plate.9 ) each material must be strong enough to withstand intracranial pressure and be compliant enough to form a seal . there are three surgical approaches for the repair of the csf otorrhea : transmastoid approach , middle fossa craniotomy , and a combined approach.3,9,10 ) surgeons can choose between these options based on the location and size of defect , their experience or preference , and better surgical view . the favored technique is a combined transmastoid - middle fossa approach , which visualizes the entire tegmen and definite closure of the entire region . but , this approach has a great potential for complications and should be performed by experienced operators . in contrast , the transmastoid approach is technically easier to perform , has fewer risks and complications , and anterior defect in the tegmen tympani may require the removal of ossicles to ensure better exposure of the lesion . it causes hearing disturbance that can be restored with ossicular reconstruction in the same or second stage . in this case , the lesion is located anteromedial side of middle cranial fossa so the combined approach could be suitable . however , we could perform in transmastoid approach with only of removal of ossicles to obtain clear view of lesion and successfully manage the defect .
spontaneous cerebrospinal fluid ( csf ) otorrhea is defined as csf otorrhea where there are no identifiable causes including previous trauma , surgery , infection , neoplasm or congenital anomaly . 
 the condition is rare . 
 the origin of csf leak is commonly a defect in the tegmen of the middle cranial fossa . 
 the pathophysiology of spontaneous csf otorrhea is unclear . 
 two theories of the etiology of bony defects of the temporal bone are the congenital bony defect theory and arachnoid granulation theory . 
 the authors experienced a case of a 49-year - old female patient admitted with the complaint of persistent right ear fullness . computed tomography revealed a large defect of the middle fossa and suspicious csf otorrhea through the defect of tegmen tympani . 
 repair was successful with multiple bone chips using the transmastoid approach . 
 the postoperative course was good and there has been no recurrence of the csf leakage .