Diseases Of The Nose Throat And Ear

RHINORRHOEA 49

patient is recumbent the fluid passes into the nasopharynx. Cerebrospinal
fluid contains a reducing substance, but this is not diagnostic as lacrimal
secretion also reduces Fehling's solution. Radiography and tomography of
the skull may locate the underlying lesion. The source of the fluid may be
tested for by placing two pledgets of cotton-wool into the anaesthetized nose,
one in the spheno-ethmoidal region in the olfactory cleft and the other in the
posterior part of the middle meatus. At lumbar puncture 1 ml of 5 per cent
fluorescein is injected and the patient is laid flat with his head dependent.
Examination under ultraviolet light will detect the dye. If the cerebrospinal
fluid arises from the frontal sinus the dye is anterior to the meatal wool; if
from the cribriform plate the wool in the olfactory cleft is stained; and if from
the sphenoidal sinus the dye will be found in the nasopharynx on posterior
rhinoscopy.

Spontaneous recession may occur, but the presence of a leak exposes the
meninges to infection from the nose. Antibiotics may be used on a long-term
basis to prevent this, and they are used should meningitis develop. Intranasal
medication or surgery is contra-indicated in this condition. Surgical repair of
the dural defect and the inlay of a strip of fascia lata to seal the cribriform
plate, the inner table of the frontal sinus or the sphenoid sinus may be
undertaken once the defect has been located.