Primary spontaneous cerebrospinal fluid rhinorrhoea

Abstract

Two cases of cerebrospinal fluid rhinorrhea are described. In one case a portion of the olfactory bulb had atrophied and the pressure of the cerebrospinal fluid formed a fistula in a neural foramen of the cribi-form plate. In the other case the arachnoid formed a loose funnel passing forward around each olfactory tract and onto the bulb instead of closely investing these structures. Also present in this case was a skull deformity consisting of a deep narrow cleft between the strongly arched orbital roof laterally and the crista galli and falx cerebri medially with the olfactory bulb sunken on its floor, A wide arachnoid cistern is consequently formed on the superior surface of the cribi-form plate and the arachnoid sheaths of the olfactory nerves are distended by normal cerebrospinal fluid pressure. Rupture of one of these enlarged nerve sheaths would produce cerebrospinal fluid rhinorrhea. The anatomical relationship between the subarachnoid space and the nasal cavity frequently presents a barrier of only a fraction of a millimeter in thickness. In view of abnormalities, as shown in these 2 cases, the normal cerebrospinal fluid pulse could produce erosion of tissue at the cribiform plate resulting in spontaneous cerebrospinal fluid rhinorrhea.