Hydrocephalus

1. Hydrocephalus
Sleshma Gautam
Intern 2017

2. Contents
 Definition
 CSF pathway
 Types
 Pathology
 Classification
 Clinical Features
 Diagnosis
 Treatment

3. Definition
 Hydrocephalus is defined as the aseptic dilatation of the brain ventricles
due to accumulation of excessive cerebrospinal fluids leading to increased
pressure, resulting from an imbalance between production, absorption
and circulation of cerebrospinal fluids.
 Derived from the Greek words “hydro” meaning water and “cephalus”
meaning head

4. CSF Pathway
CSF is secreted at the choroid plexus within the
lateral ventricle by ultrafiltration and active
secretion
Foramen of monro
3rd ventricle
Aqueduct of sylvius
4th ventricle
Foramina of Luschka and Magendie
Subarachnoid space
In the subarachnoid space, it gets absorbed with the help of subarachnoid
villi

5. Types
1. Communicating hydrocephalus: no blockage between the ventricular system,
the basal cisterns and the spinal subarachnoid space. Either due to excessive
production or decrease in absorption. Usually present at birth
Eg: Achondroplasia, Meningitis, Meningeal malignancies, choroid plexus
papilloma, posthemorrhagic
2. Obstructive or non-communicating hydrocephalus: The block is at any level
in the ventricular system, commonly at the level of cerebral aqueduct or
foramina of Luschka and Magendie. develops after birth
Eg: Aqueductal stenosis, Arnold- Chiari malformation, Dandy-
Walker malformation, Klippel-Feil syndrome, mass lesions, abscess,
hematoma

6. Pathology
 Ventricles are dilated, at times unevenly
 Ependymal lining of ventricles is disrupted resulting in periventricular ooze
 Subependymal edema occurs
 Cortex is generally preserved until late but cortical atrophy may occur
 May be reversible if the treatment is started early

7. Etiological Classification of Hydrocephalus
A. Congenital Hydrocephalus
1. Aqueductal stenosis
2. Intrauterine infections: TORCH infections (Toxoplasmosis, Rubella, CMV)
3. Arnold-Chiari malformation: portions of cerebellum and brainstem herniating
into cervical spinal canal, blocking the flow of CSF to the posterior fossa
4. Neural tube defects: encephalocele, spina bifida
5. Dandy Walker malformation: posterior fossa cyst continuous with fourth
ventricle
6. Intracranial bleed, intraventricular hemorrhage
7. X-linked inherited disorders: Bickers-Adams syndrome
8. Midline tumors obstructing CSF flow

8. B. Acquired hydrocephalus
1. Tuberculous, chronic and pyogenic meningitis
2. Post-intraventricular hemorrhage
3. Posterior fossa tumors: medulloblastoma, astrocytoma, ependymoma
4. Arteriovenous malformation, intracranial hemorrhage, ruptured aneurysm
5. “Hydrocephalus ex vacuo”

9. Clinical features
Infants: Early
 Abnormally rapid enlargement of head
 Bulging fontanels
 Prominent dilated scalp veins
 Delayed closure of fontanel, widening of sutures
 “Setting sun sign”: Ocular globes are deviated
downward, the upper lids are retracted, and the white
sclera may be visible above the iris
 Macewen sign (cracked pot sound on percussion of skull
near the junction of the frontal, temporal and parietal
bones)

10.  Irritability, high pitched cry
 Lethargy
 Seizures
 Vomiting
 Poor feeding, poor growth
 Papilloedema
 Pyramidal tract signs : Increased limb tone (spasticity) preferentially affects
the lower limbs
 Cranial nerve palsy

11. Among toddlers and older children
 Headache
 Blurred vision due to Papilloedema
 Urinary incontinence
 Strabismus (Abducent nerve palsy)
 Irritability, lethargy
 Behavioral disturbances
 Confusion
 Nausea and vomiting
 Pyramidal tract signs such as spasticity, hyperreflexia, positive Babinski sign

12. Diagnosis
1. History collection
2. Physical findings in infants include the following:
a) Vital signs:
 Bradycardia due to pressure on brain stem
 Systemic hypertension
 Altered respiration & sometimes apnea

13. b) Head
 Suspected if rapid head enlargement (i.e. increase in HC > 1 cm every fortnight in
first 3 months)
 Macewen sign: A "cracked pot" sound is noted on percussion of the head (open
fontanels).
 Transillumination of the skull is positive
 Delayed closure of sutures
 Dilated scalp veins
 Bulging of fontanelle
In older children
 Large head: Sutures are closed, but chronic increased ICP will lead to progressive
macrocephaly.

14. c) Eyes
 Setting-sun sign: In infants, it is characteristic of increased intracranial
pressure (ICP).
 Papilledema: If the raised ICP is not treated, this can lead to optic atrophy
and vision loss.
 Failure of upward gaze
 Unilateral or bilateral sixth nerve palsy (abducens) is secondary to
increased ICP (strabismus)

15. Other diagnostic test
Cranial Ultrasound:
 In congenital hydrocephalus, a routine antenatal ultrasound may detect
the condition during the pregnancy in developing fetus
 Helps to evaluate the ventricular size

16. CT SCAN & MRI: Gives information about the ventricular size, periventricular
ooze, site of obstruction

17. Treatment
Medical Management
 The goal of treatment of hydrocephalus is to reduce or prevent brain damage by
improving the flow of CSF.
 The following medications are used to treat hydrocephalus:
 Acetazolamide at a dose of 25-100 mg/kg/day : helps in lowering intracranial pressure
 Oral glycerol : reduces the volume of cerebrospinal fluid and lowers intracranial pressure
 Furosemide 1mg/kg

18. Surgical treatment
Indications:
 Rapid enlargement of head size
 Progressive symptoms where vision or life is endangered
Options:
 Shunting
 Endoscopic procedures
 Eliminating the cause of obstruction

19. Shunting
 A shunt system consists of the shunt, a catheter, and a valve.
 Diverts CSF from the ventricles into the systemic circulation or to a
cavity (peritoneum, pleura, gall bladder, ureter).
A. Ventriculo-peritoneal shunting
 Most commonly used.
 Shunt Placement:
The neurosurgeon makes a small incision in the scalp to
access the lateral ventricle of the brain.
The catheter is then carefully threaded through brain tissue
or under the skin to reach the abdominal cavity.
The distal end of the catheter is placed within the
peritoneal cavity.

20.  Ventriculo-atrial shunting: Diverts CSF from the
ventricles into the into the right atrium

21. Complications
1. Infection - Most serious complication.
 Septicaemia
 Bacterial endocarditis
 Wound infection
 Meningitis
 Ventriculitis
2. Malfunction: All shunts are subject to mechanical difficulties like kinking, plugging,
separation or migration of tubing

22. Endoscopic third Ventriculostomy
 In this procedure, an endoscope is used to make a small opening in the bottom/
floor of 3rd ventricle to enable cerebrospinal fluid to flow freely through the
previously blocked ventricle.
 Complications
 Intraventricular hemorrhage
 Meningitis

23. EVD - External ventricular drain
 EVD is a medical device used to remove excess
cerebrospinal fluid (CSF) from the brain's ventricles.
 It is a temporary solution often employed in
emergency situations or for short-term
management of hydrocephalus
 A thin, flexible tube (catheter) is inserted through a
small hole in the skull, typically into one of the
lateral ventricles of the brain.
 The catheter is connected to an external drainage
system, which allows cerebrospinal fluid to be
collected and monitored.

24. References
 Nelson Essentials of Pediatrics; Karen Marcdante MD, Robert M. Kliegman MD, et al.
6th edition
 Ghai Essential Paediatric; 8th edition
 UpToDate