Surgical management of spontaneous cerebrospinal fluid rhinorrhea arising from clival defects

Introduction

Although cerebrospinal fluid (CSF) rhinorrhea has been recognized for centuries, spontaneous CSF rhinorrhea was first described by St. Clair Thomson as a distinct subgroup in 1899. Spontaneous CSF rhinorrhea is rare, representing only 3% to 4% of all cases. Head trauma accounts for 80% of cases, and the remaining 16% are iatrogenic in origin. Common sites of spontaneous CSF rhinorrhea include the cribriform plate, sella, sphenoid sinus, and ethmoid air cells. Spontaneous CSF rhinorrhea arising from a clival defect is uncommon, with only seven cases described in the world literature.

Classification

To date, there is no universally accepted classification system of CSF rhinorrhea, although several systems have been described. O’Connell provided a classification system for spontaneous CSF rhinorrhea, dividing cases into primary and secondary groups. Primary CSF rhinorrhea is described as cases in which no cause of the leak can be found, and secondary CSF rhinorrhea represents cases in which the cause is evident, such as with intracranial neoplasms, hydrocephalus, congenital abnormalities, osteomyelitis, and focal atrophy.

An alternative classification system proposed by Ommaya categorizes CSF rhinorrhea cases as high pressure, typically in the setting of tumors and hydrocephalus, or low pressure, such as congenital abnormalities, osteomyelitis, focal atrophy, and so on.