This document summarizes cerebrospinal fluid (CSF) implications in oral and maxillofacial surgery. It discusses CSF anatomy, physiology, clinical significance of CSF leaks, etiology and management of CSF leaks seen in oral and maxillofacial surgery. CSF is formed in the choroid plexus and circulates through ventricles in the brain before being absorbed. CSF leaks can occur due to trauma, surgery or spontaneously. Evaluation involves clinical examination, imaging and laboratory tests. Management includes conservative medical treatment or surgical repair depending on the severity and persistence of the leak. Surgical techniques include lumbar drains, intracranial or extracranial repairs, and endoscopic approaches.

1. Journal club

2. CEREBROSPINAL FLUID: IMPLICATIONS
IN ORAL AND MAXILLOFACIAL SURGERY
M. Todd Brandt, W. Scott Jenkins, Tirbod T Fattahi, Richard H Haug.
JOMS 2002; 60: 1049-1056.

3. Introduction
 CSF is an essential component of the nervous system.
 Serves as cushion, lubrication for cerebral hemisphere and
meningeal layer.
 CSF fistula and leaks are documented in variety situation trauma,
skull base surgery, functional endoscopy, spontaneous.
 Galen in 2nd century AD, first documented the description of CSF
fistula(rhinorrhea)
 First correlation of CSF rhinorrhea with craniomaxillary trauma
was made in 17th century by Bidloo & Elder.
 CSF fistula is serious potential fetal condition, successful
management requires through understanding of pertinent
anatomy & path physiology.
 This article reviews the anatomy & path physiology of CSF ,
clinical significance of CSF fistula , highlights on etiology and
management of CSF leaks seen in OMFS.

4. Anatomy
Choroid plexus
Lateral ventricle
 CSF is formed in the
Third ventricle
choroid plexus
Forth ventricle
around the lateral
ventricle and lesser
amount by 3rd & 4th
ventricle. Partly by
arachnoid villi with
rate of 0.35-
0.40ml/min.

5. Lateral ventricles
Intra ventricular foramina
Monroe foramina
Circulation &
absorption of 3rd ventricles
CSF Cerebral aqueduct of midbrain
4th ventricles
laterally medially
Foramina Luschka Foramina Magendie
Sub arachinoid space
Central canal of spinal cord
Superolateral surface of cerebrum
Subarachnoid space around
spinal cord &
Arachoid granulations Inferior surface of cerebrum
cauda equina
Superior sagittal sinus Tentorial notch Veins of spinal cord

7. Physiology
 CSF termed as third circulation.
 Clear fluid bathing the brain & meninges produced on daily basis
in ventriculocisternal portion of nervous system.
 In adult avg intracranial volume is 1700ml, CSF makes about 5-
10% volume (50-160 ml).
 Rate of formation is 20-22ml/hr or 500ml/day or 0.35-0.40
ml/min.
 CSF as a whole is renewed 4-5 times a day.
 In recumbent position intra cranial pressure is 8-12 mm Hg or
110-150 mm H2O (ie equilibrium to capillary pressure)
 Autoregulation maintains the intracranial pressure irrespective
of ↑ arterial pressure.
 Co2 has profound effect on the CSF pressure.
 Hyperventilation: rapid ↓ in Pco2, ↑ pH & ↓ the CSF pressure.

8. Function of CSF:
1. Serves as water cushion for brain & spinal cord
protect from blunt force trauma.
2. Provides the media to support the nervous system
in closed bony cavity and protect by countercoup
mechanism.
3. No lymphatic channels in nervous system , serves
to remove the cerebral metabolic waste.
4. Active transport & passive diffusion allows
exchange of electrolyte and fluid between plasma &
extracellular space around choroid cell.

9. Various constituent of CSF.
Constituents CSF Serum Nasal secretion
Osmolarity 295 295 277
(mOsm/L)
Na (mEQ/L) 140 140 150
K (mEQ/L) 2.5-3.5 3.3-4.8 12-41
Cl (mEQ/L) 120-130 100-106 119-125
Glucose (mg/100ml) 58-90 80-120 14-32
Albumine (of total 50-75% 55% 57%
protein)
Total protein (mg/dL) 5-45 6-8.4 335-636
IgG (mg/100ml) 3.5 1140 51
B2 Transferrin 15 0 0

10. Incidence of CSF leak
 CSF not common in all the trauma.
 Reports suggests 80% CSF leaks are direct results of
trauma ( craniomaxillary trauma- naso-orbito-ethmoidal
#, postrior table frontal sinus #, skull base #)
 closed head injury with basilar skull # and CSF leaks range
from 2%-30%.
 16% occurs secondary to surgery (iatorgenic nasal,
paranasal, skull base surgery, functional endoscopic
procedure)
 remaining 4% spontaneous in origin(hydrocephalus, brain
tumor, congenital anomaly)
 Pediatric population presents with lower CSF leaks as
facial skeletal development not reached the maturation &
sinus pneumatization is incomplete,

11. Patho-physiology
 It presents as CSF Rhinorrhea or CSF otorrhea.
 most of times, occurs through anterior cranial fossa
as at this region dura is tightly adhered to thin bone
of cribriform plate and roof of ethmoid.
 factors affecting nature of leak-
 Disruption of arachinoid & dura laceration, tear in
periosteum & mucosa.
 Degree of displacement of bony fragments.
 Intracranial pressure
 Increased production of CSF

12. Classification
Ommaya classification system for CSF leak (1964)
Traumatic (80-90%) Non-traumatic (10-20%)
Accidental (Cranimaxillofacial fractures) High pressure leaks
1. Tumors
2. Hydrocephalous
3. Benign intracranial hypertension
Iatrogenic (neurosurgical & functional Normal pressure leaks
endoscopic procedures) 1. Congenital anomaly
2. Focal atrophy
3. Osteomyelitic erosion

13. Evaluation
Clinical presentation Clinical/Laboratory Imaging
identification
1. Otorrhea (25%), Clinical- 1) Plane radiographs , CT
rhinorrhea (68%) 1) Reservoir sign scans: disruption of bony
2. High suspicious 2) Target sign (ring test) architecture, air or fluid level,
with epistasis, 3) Altered ICP causes headaches. tumor masses.
pharyngorrhea, 4) Low pressure- headache to be 2) Cysternography :
hemotympanum relieved by staining or a. non radioactive dyes-
, battels sign, performing Valsalva Methylene blue, phenol
post traumatic movement . sulfonphthalein, flurescin.
serous otitis 5) High pressure- headache b. Radioactive agent-
media. relieved by release of CSF eg Indium 11diethyleen
3. CSF leaks should lumbar puncture triaminic penta acetic acid
be assumed until Laboratory- (DPTA), technetium 99m-
ruled out. 1) Glucose CSF conce ≥ plasma DPTA.
2) ↓Protein & K+ level c. Combination of imaging
3) β2 transferrin along with contract medium
(metrizamide)

14. Clinical management-
 Conservative medical approach
 Surgical intervention

15. Conservative medical approach
 Strict bed rest
 Head elevation 35 ° -45°
 Instruction to avoid activity that ↑ ICP (coughing,
nose blowing, sneezing, straining)
 Stool softener
 Acetazolamide (↓ CSF production )
 Incidence of meningitis is 3%-50% and mortality
associated with post traumatic meningitis is 10%
 Antibiotic prophylaxis is not recommended
Clemenza et al

16. Protocol for surgical intervention
 Spontaneous closure of CSF fistulas within 48 hrs = 68%, 1 week
= 85%.
 With reduction of craniofacial fracture CSF leaks resolve
spontaneously
 During reduction any suspicion regarding posterior frontal table,
orbito-ethmoidal #, fistulas are obliterated with galeal flap or
fat.
 If conservative management of facial # to slow the leak with 72
hr, lumbar subarachnoid drain placed ( if no indication for
craniotomy)
 Persistent leak > 8days despite of subarachnoid lumbar drain,
craniotomy is require to repair the CSF fistula.
 Surgery can be performed extra cranially ( endoscopic or
transfacial) intracranially (craniotomy)

17. Patient selection for surgical repair
 Complication of CSF fistula – tension meningitis, pneumocele.
 ↓ Incidence of meningitis (9%), {post traumatic meningitis organism
asso. Pneumococcous species}
 Repair of basal dural tear can prevent meningitis (Teasdaie &
Jennett)
 Classification of compound skull fracture by Sakas et al
 I- Cribiform
 II- Fronto-ethmoidal
 III- lateral frontal
 IV- complex(any combiantion of above).
 Type I are more prone fro infection than type II & III (near to sagittal
midline are prone for infection)
 Large fracture with max bone displacement (> 1 cm any plane .
 Patient with transient rhinorrhea >8 days high risk of meningitis.

18. A. Lumbar drain-
 First indwelling catheter was reported in 1963.
 these are subarachnoid lumbar drain effectively
reduce the hydrostatic pressure.
 Drains are kept for 4-10 days, drains CSF about 150
ml /day.
 Risk of meningitis ↑ up to 10% when lumbar drains
violate the subarachnoid space.
 procedure may also present with complications
like transient lumbar nerve root irritation, CSF
overdraining leading temporary neurological
decline.

19. B. Intracrainal repair-
 Dandy 1926, first described intracranial repair of CSF fistula.
 Craniotomy
Advantage-
 Direct visualization of dural tear.
 Allows inspection of adjacent t brain injury
 Preferred when extracranial approach has failed.
Disadvantage-
 Asomia
 Intracranial hemorrahge
 Brain edema
 Skull base exposure
 Brain retraction

20. C. Extracranial repair-
 Dohlman 1948, first extra cranial approach for CSF
fistula repair.
 Appproaches-
 External ehtmoid-sphenoidal (medial orbital
incision, dissect orbital content posteriorly to gain
ethmoidal labyrinth, fistula repair can be done with
fascial late, muscle, fibrin glue)
 Transmastoid (with high speed bur mastoid air cells
are removed)
 Transseptosphenoidal (trans nasal route),

21. D. Endoscopic repair
 Overall success 98%,
 Can address ethmoidal roof, cribiform plate,
sphenoidal defects
 Recommended when defect is < 1 cm.
Disadvantage-
 Limited visualization
 Possible cerebral damage.

22. Post operative care
 Patient going for the surgical repair shunts are kept
at adjacent to direct repair
 Shunts are kept appro 4-10 days
 Antibiotic prophylaxis for the patient with higher risk
of meningitis, preexisting sinusitis, compound skull
base fracture with gross contamination.
 Nafcillin, gentamicin, cephazolin excellent choice.
 Surgical pack with antibiotic is kept to reduce
bacterial endotoxin.

23. Thank you…