CSF Rhinorrhoea

CSF rhinorrhoea presents as flow of clear fluid from the
nose.
Aetiology.
(i) Traumatic: Head injuries, surgery of frontal, ethmoid
or sphenoid sinus or hypophysectomy. It may
follow as a complication of endoscopic sinus surgery.
It may be immediate or delayed in onset.
(ii) Tumours: Large osteomas of frontoethmoid region,
tumours of the pituitary or the olfactory bulb.
(iii) Congenital defects in skull associated with
encephalocele.
(iv) Spontaneous type.
Sites of leakage. CSF from anterior cranial fossa
reaches the nose by way of cribriform plate, ethmoid air
cells or frontal sinus. CSF from middle cranial fossa
reaches the nose via sphenoid sinus. Sometimes, injuries
of temporal bone result in leakage of CSF into the middle
ear and thence via the eustachian tube into the nose
(otorhinorrhoea) .
Diagnosis. There is history of dribbling of clear fluid
from the nose on bending or straining. CSF rhinorrhoea
should be differentiated from nasal discharge of allergic
or vasomotor rhinitis. Discharge in CSF rhinorrhoea is
clear and watery, appears suddenly in a gush of drops
when bending forward or straining, is uncontrollable and
cannot be sniffed back. There is no associated sneezing,
nasal congestion or lacrimation. When collected into a
test-tube and allowed to stand, it remains clear in contradistinction
to nasal discharge that leaves a sediment
because of mucus and other proteins. This is also the reason
that a nasal discharge stiffens the handkerchief. CSF
contains glucose which can be demonstrated by oxidaseperoxidase
paper strip or biochemical tests. f32 transferrin
is specific for CSF. Itis absent in nasal secretions or tears.
Its presence confirms the diagnosis of CSF leak.
Localisation of CSF leak. It is done by intrathecal
injection of a dye (fluorescein 5%, 1 ml) or a radioisotope
and placing pledgets of cotton in the olfactory slit,
middle meatus, sphenoethmoidal recess and near the
eustachian tube and examining the pledgets for dye or
rad ioactivity.
Olfactory slit--> Cribriform plate
Middle meatus--> Frontal or ethmoid sinuses
Sphenoethmoidal recess --> Sphenoid sinus
Inferior meatus near the --> Temporal bone
eustachian tube