Spontaneous Cerebrospinal Fluid Otorrhea

Cerebrospinal fluid (CSF) leaks are extracranial egress of CSF into the adjacent nasal sinus or tympanomastoid cavity due to an osteodural defect involving skull base. They can be due to a multitude of causes including accidental or iatrogenic trauma, congenital malformations (see Figs. 3.22 and 8.1 ), and spontaneous leaks. Accurate localization of the leak site, underlying causes and appropriate therapy are necessary to avoid associated complications (Hiremath et al. 2019). Spontaneous CSF leaks are those leaks which lack underlying pathologies such as skull base lesions, congenital abnormalities and those with no history of trauma or surgery. It is relatively rare, but is commonly seen in obese, middle-aged women who present with idiopathic intracranial hypertension. Typical imaging findings include prominent arachnoid granulations causing skull base erosions, empty sella, and meningoencephalocele, et al. (Bathla and Moritani 2016) (Fig. 12.1).