Csf rhinorrhoea

GURJEET SINGH VI TERM

DEFINITON

Leakage of CSF into the nose is called CSF rhinorrhoea.Clear fluid.mixed with blood (in acute head injuries).

PHYSIOLOGY

CSF forms a jacket of fluid round the brain and spinal cord acting as a buffer against sudden jerks.

Secreted by choroid plexus in the lateral,third & fourth ventricle & absorbed into dural venous sinuses by arachnoid villi.

Villi have one-way valve mechanism allowing CSF of the subarachnoid space to be absorbed in to the blood .

Total volume of CSF varies 90 to 150 ml.

Cont.

It is secreted at the rate of about 20ml/hr (350-500mL/day). Thus total CSF is replaced three to five times every day. CSF pressure rise on coughing, sneezing, nose blowing

straining on stools or lifting heavy weight. These activities should be avoided in cases of CSF leak or

after its repair.

CSF PRESSURE

Normal CSF pressure at lumbar puncture is 50-150mmH2O.

ETIOLOGY

Trauma (commonest) Accidental Surgical ( FESS, nasal polypectomy, trans-sphenoidal

hypophysectomy,skull base surgery) Neoplasms (benign/malignant) invading skull base Inflammations (mucocele of sinuses ,sinunasal polyposis, fungal

infections of sinuses & osteomyelitis erode the bone & dura)

Congenital (meningocele,meningoencephalocele & gliomas with skull base defect)

Idiopathic

SITES OF LEAKAGE

1. CSF from Anterior cranial fossa reaches the nose via

a) Cribriform plate

b) Roof of ethmoid

c) Frontal sinus

2. CSF from Middle cranial fossa 1. injuries to sphenoid sinus

2. In fracture of temporal bone CSF ME ET nose (CSF otorhinorhea)

DIAGNOSIS

h/o clear watery discharge on bending head/ straining sudden gush can’t be sniffed back Reservoir sign :

When rising in morning CSF collected in sinuses on bending head

CONT.

After a head trauma Double target sign when collected on a piece of filter

paper with central blood & peripheral lighter halo

Cont.

Nasal endoscopy localize site of CSF leak. Otoscopic /microscopic examination of ear } REVEAL FLUID

in case of CSF otorhinorhea.

CONT.

LABORATORY TESTS

B2 transferrin Sensitive & specific Only few drops of CSF is needed Perilymph & aqueous also contains it but not in nasal discharge

Beta trace protein Specific for CSF

Glucose testing > 30 mg/dl in CSF <10 mg/dl in nasal discharge

LOCALIZATION OF SITE

High resolution CT scan Coronal & axial cuts at 1-2 mm } bony defects Axial } frontal & sphenoid sinus

MRI T2 weighted image Site of leak Active CSF leak is needed Non invasive

CONT.

Intrathecal fluorescein study it can be done preoperative invasive procedure 0.25-0.5 Ml of 5% fluorescein diluted with 10mL of CSF is injected. patient lies in 10 degree head down position. dye can be detected intranasally with the help of endoscope dye appears bright yellow but when seen with blue filter it appear fluorescent green. localize the lesion Use of intrathecal radioactive substance has been abandoned.

Cont.

CT cisternogram Localise the lesion Intrathecal injection of iohexol & CT Where B2 transferrin can’t be done

Cont.

Coronal CT cisternogram showing CSF draining from the subarachnoid space through the roof of the right ethmoid sinus (arrow) into the nose.

TREATMENT

Early case of post traumatic Case of CSF rhinorrhea can be managed by Conservative measures Bed rest Elevating the head of bed Stool softeners Avoidance of nose blowing, sneezing & straining Prophylactic antibiotics can be used to prevent meningitis Acetazolamide ↓ formation of CSF

SURGICAL REPAIR

Neurosurgical intra cranial approach. Extra dural approach

External ethmoidectomy } cribriform plate. Trans septal sphenoidal approach } sphenoid. Osteoplastic flap } frontal sinus leak.

CONT.

Trans nasal endoscopic approach With endoscope

Site of leak

1. Cribriform plate

2. Lateral lamina close to anterior ethmoid artery

3. Roof of ETHMOID

4. Frontal sinus leak

5. Sphenoid sinus

Cont.

Preparation of graft siteUnderlay grafting of fascia extradurally (mucosa for small

defect….. Septal cartilage if>2cm)Surgical & gelfoam strengthen followed by high antibiotics

smeared nasal pack.Lumbar drain if CSF pressure is highAntibiotics

Cont.

CSF RHINORRHOEA?

Confirm presence of leak

History examination Glucose/ β2 transferrin

Nasal endoscopyTraumatic/Atraumatic

conservative

failure successful

localization

Surgical closure