Isotope Cisternography in the Diagnosis and Follow-Up of Cerebrospinal Fluid Rhinorrhea

OCALIZATION of the leakage site in cases of cerebrospinal fluid (CSF) rhinorrhea, both posttraumatic and spontaneous (nontraumatic), is often an arduous and always a challenging diagnostic problem. The possible sites are numerous: through the frontal sinus, the lamina cribrosa, the sphenoid sinus via the sella, and the petrous bone via the middle ear and the eustachian tube (Fig. 1). Furthermore, the fistula may be located on the side opposite to the dripping nostril or the sources of leakage may be multiple. Diagnostic procedures for CSF rhinorrhea include the use of dyes, fluorescent substances, radiography, and radioactive tracers (Table 1). Dyes and fluorescein usually are not very informative for the localization of the fistula and, in addition, may be dangerous. ~6,34,~ Plain x-rays and even detailed tomographic studies are frequently disappointing. In our opinion no convincing evidence has yet been offered for the value of Pantopaque as a localizing agent for the CSF leaks, and this x-ray opaque medium is not always innocuous. 18,28 Radioactive counting of cotton pledgets placed in strategic points of the walls and roof of the nose and nasopharynx prior to the subarachnoidal introduction of a radiation emitter 4,35 fails to give morphologic information about the leakage. This report deals with the diagnostic possibilities of isotope cisternography (pictorial scintiphotography of the head after introduction of a radioactive tracer into the subarachnoidal spaces) for the localization, demonstration of the cause, and follow-up of cerebrospinal fluid rhinorrhea. We have used