Hydrocephalus is an accumulation of cerebrospinal fluid (CSF) in the brain that increases intracranial pressure. It can be caused by overproduction of CSF, impaired absorption of CSF, or blockage of CSF flow pathways. Common symptoms include headache, nausea, vision changes, and altered consciousness. Treatment options include removing any underlying cause, reducing CSF production, bypassing obstructions, intermittent CSF drainage, and CSF shunting. CSF shunting involves placing a catheter in the brain ventricles connected to a shunt valve and distal catheter to drain excess CSF, usually into the abdomen. Potential shunt complications are blockage, infection, and over-drainage.

1. HydrocephalusHydrocephalus
Amina Al-QaysiAmina Al-Qaysi

2. HydrocephalusHydrocephalus
• Derived from the Greek words “hydro”
meaning water and “cephalus” meaning
head.
• Disequilibrium between CSF production
and absorption, leading to raised ICP, and
is often associated with dilated ventricles.

3. Cerebrospinal Fluid PathwayCerebrospinal Fluid Pathway
• Formed by the choroid plexus, by
ultrafiltration (active process independent
of ICP).
• From lateral ventricles into 3rd
ventricle
through inter-ventricular foramen of
Munro.
• From 3rd
ventricle into 4th
ventricle through
aqueduct of Sylvius.
• Foramen of Magendie & Luschka.

5. • Subarachnoid space, Spinal canal.
• Absorbed by Arachnoid villi into the
superior sagittal sinus (pressure-
dependent passive process).
• CSF Volume: 150 ml.
• CSF Production: 20 ml/h.
• Normal ICP: 5-15 mmHg in the adult at
rest.
• CSF act as a hydraulic shock absorber.

6. Types of HydrocephalusTypes of Hydrocephalus
1. Communicating:
• CSF pathways are patent, CSF can
leave the 4th
ventricle & communicate
with subarachnoid space.
• Impaired CSF absorption.
2. Non-communicating: Lesion blocking
CSF pathways.

7. AetiologyAetiology
• Obstructive hydrocephalusObstructive hydrocephalus::
1. Lesions within the ventricle.
2. Lesions in the ventricular wall.
3. Lesions distant from the ventricle but with a
mass effect.

8. • Communicating hydrocephalusCommunicating hydrocephalus::
1. Post haemorrhagic (SAH).
2. CSF infection (meningitis).
3. Raised CSF protein.
• Excessive CSF productionExcessive CSF production::
Choroid plexus papilloma/carcinoma (rare).

10. Normal-Pressure HydrocephalusNormal-Pressure Hydrocephalus
• Communicating hydrocephalus.
• Thought to be due to impaired CSF
absorption.
• Mostly in elderly.
• Adam’s triad: ataxia, cognitive decline &
urinary incontinence.
• Ventriculomegaly on imaging.
• Normal CSF pressure.
• Respond to ventriculo-peritoneal shunting.

11. Symptoms of Raised ICPSymptoms of Raised ICP
• Headache: Early morning, Worse on lying
down.
• Nausea & vomiting.
• Visual blurring or double vision.
• Drowsiness.
• Altered level of consciousness.

12. Signs of Raised ICPSigns of Raised ICP
• Papilledema.
• 6th
nerve palsy.
• Impaired upgaze.
• Focal neurological
deficits.
• Impaired conscious
level.
In infants:
• Progressive
macrocephaly.
• Bulging, tense
anterior fontanelle.
• Dilated scalp veins.
• Sun-setting eyes.

14. Sun-Setting EyesSun-Setting Eyes

15. PapilledemaPapilledema

16. InvestigationsInvestigations
• Plain skull X-Ray: Copper-beating
appearance.
• Ultrasound: child with open fontanelle.
• Brain CT scan.
• MRI.
• ICP monitoring: Parenchymal probe
placed into the frontal lobe.

17. Copper-BeatingCopper-Beating

19. InvestigationsInvestigations cont’dcont’d
Lumbar puncture:
• Non-Communicating hydrocephalus:
Contraindicated, risk of tonsillar herniation &
death.
• Communicating hydrocephalus: Both
diagnostic (measuring CSF opening
pressure) & therapeutic (draining CSF).

20. Treatment PrinciplesTreatment Principles
1. Removal of cause.
2. Reducing CSF production.
3. Bypassing the obstruction.
4. Intermittent removal of excess CSF.
5. CSF shunting to a place where it can be
absorbed.

21. TreatmentTreatment
Removing a causative mass lesion:Removing a causative mass lesion:
• Tumour removal & decompression of CSF
pathways, with insertion of external
ventricular drain.
• Patient who presents with impaired
conscious level, treat the hydrocephalus
first with EVD or VP shunt, followed by
tumour surgery.

22. Reducing CSF productionReducing CSF production
1. Carbonic Anhydrase inhibitor:
Acetazolamide.
• Temporary effect.
• Careful monitoring of electrolytes levels.
2. Destroy choroid plexus by open
operation, or using endoscope.
• No widely used.

23. Endoscopic third ventriculostomyEndoscopic third ventriculostomy
• Bypass the obstruction.
• Neuroendoscope inserted into the frontal
horn of lateral ventricle, then into the 3rd
ventricle through foramen of Munro.
• Stoma created in the floor of 3rd
ventricle in
between the mamillary bodies and
infundibular (pituitary) recess.
• CSF can communicate freely between the
ventricular system & interpeduncular
subarachnoid space.

25. • Useful if there is CSF pathways
obstruction below the 3rd
ventricle
(aqueduct stenosis or posterior fossa
mass lesions).
• Less useful for communicating
hydrocephalus, & in infants of less than 6
months of age.
• Success rate: 70%.

26. • Advantage: no tubing is left in the
patient, infection rates are lower.
• ComplicationsComplications::
1. Blockage.
2. Basilar artery rupture.
3. Memory impairment from injury to the
fornix.

27. Remove Excess CSFRemove Excess CSF
1. Ventricular tapping.
2. Ventricular drainage.
3. Lumbar puncture.
• Temporary measures.

28. Ventriculo-peritoneal shuntVentriculo-peritoneal shunt
• Catheter insertion into the lateral ventricle.
• Connected to a shunt valve under the scalp
and finally to a distal catheter, which is
tunnelled subcutaneously down to the
abdomen and inserted into the peritoneal
cavity.
• When CSF pressure exceeds the shunt valve
pressure, CSF flow out of the distal catheter
and be absorbed by the peritoneal lining.

29. Various types of CSF shuntVarious types of CSF shunt

30. Other options for distal catheter placement
include:
1. Right atrium via the jugular vein:
ventriculo-atrial shunt.
2. Pleural cavity: ventriculo-pleural shunt.

32. Shunt ComplicationsShunt Complications
Shunt blockageShunt blockage::
• May affect the ventricular catheter, shunt
valve or distal catheter.
• Causes: choroid plexus adhesion, blood,
cellular debris, misplacement of the
distal catheter in the pre-peritoneal
space (child growth), high protein
content in CSF.

33. Shunt InfectionShunt Infection::
• 1 - 15% of inserted shunts.
• Staphylococcus epidermidis.
• Risk factors: very young children, open
myelomeningocele, longer operative time,
excessive staff movement into and out of
theatre.
• Most infections become apparent clinically
by 6 weeks and over 90% are apparent
within 6 months.

34. • Cause: meningitis, peritonitis,
septicaemia, endocarditis.
• Treatment:
Shunt removal, external CSF drainage,
treatment of infection prior to re-insertion
of the shunt at a different site.
• Antibiotic-impregnated catheters resulted
in reduction in shunt infection rates.
• Prophylactic antibiotics.

35. • Over-drainage: result in subdural
haemorrhage, slit ventricle syndrome,
microcephaly.
• Seizures: 5%.
• CSF leak, Stroke, Intracerebral
haemorrhage (< 1%).

36. Follow up of shunt patient:Follow up of shunt patient:
• Every 3 months in 1st
year following shunt
placement.
• Every 6 months in 2nd
year.
• Then yearly.

38. External drainsExternal drains
• Placed within the ventricle (EVD) or the
lumbar thecal sac (lumbar drain).
• For temporary CSF drainage.
• Can be used to administer intrathecal
antibiotics to treat CSF infection.

39. PrognosisPrognosis
• Depends on the cause of hydrocephalus.
• Simple aqueduct stenosis treated early,
prognosis of normal IQ & neurologic
function is good.
• Repeated episodes of raised ICP &
ventriculitis, results in low IQ & neurologic
function.

40. ReferencesReferences
• Bailey & Love’s Short Practice of Surgery, 25th
edition, Chapter 40, P. 623-628.
• Sabiston Textbook of Surgery, 18th
edition,
Chapter 72.
• Schwartz's Principles of Surgery, 8th
edition,
Chapter 41.
• Greenfield’s Surgery, 4th
edition, Chapter 114, P.
2067-2068.
• Clinical Surgery, Cuschieri, 2nd
edition, Chapter
40, P. 632-633.
• Principles of Neurosurgery, Rengachary, 2nd
edition, Chapter 8 & 9, P.117-134.