Hydrocephalus for UG students - Dr. D. Gunasekaran, Professor of Pediatrics, MGMCRI

1. MACROCEPHALY
Dr. D. Gunasekaran,
Consultant Paediatrician,
MGMC & RI, Pondicherry

2. Macrocephaly - Definition
> 2 S.D above the mean for the age & sex
OR
> 97th
percentile for the age & sex
OR
> 2.5 cms above the mean for age & sex

3. Macrocephaly
How to find out the expected HC for a particular
child?
Only by comparing the standardized charts
which shows HC for a particular age & sex

5. Normal HC at birth
At birth 33-35cm
<3 months 2 cm / month
3-6 months 1cm / month
6 months – 1 year 0.5 cm / month
1-3 years 1cm / 6 months
3-5 years 1cm / year

7. Macrocephaly - causes
Big skull
Big brain
More CSF in ventricles
Abnormal accumulation
Familial
Chronic anemia, O.I, Rickets
Megalencephaly (Tay-sach),
Cerebral gigantism
Hydrocephalus
Subdural effusion
Commonest (at the community level)

8. Hydrocephalus
Greek word – “water in head”
Definition: Excessive accumulation of CSF
in the ventricular system

9. Normal CSF
Normal Volume of CSF:

10. Normal CSF
Normal Volume of CSF:
Newborn: total of 24 ml at any time
Adult: total of 150 ml, at any time
1 hour : 24 ml production

11. Normal CSF Pressure
Normal ICP:
Newborn: 10-20 cm H2O
Infants: 20-80
Older child: 40-100

12. Hydrocephalus – Normal CSF
Where is CSF formed?
Choroid Plexus in Lateral Ventricles (75%)
Choroid Plexus in 3rd
& 4th
Ventricles
Capillary endothelium
It is actually an ultra filtrate of Plasma

13. Hydrocephalus – Normal CSF
How CSF Circulates in side the skull and Spinal
cord?

14. Pathways of
CSF

15. CSF PATHWAY



CSF IS FORMED IN THE LATERAL VENTRICLE
3RD
VENTRICLE THROUGH FORAMEN OF
MONRO
4TH
VENTRICLE THROUGH AQUEDUCT OF
SYLVIUS
INTO SUBARACHANOID SPACE of spinal cord
THROUGH FORAMEN OF LUSCHKA & MAGENDIE

16. Hydrocephalus – Normal CSF
Where CSF is absorbed?
Arachnoid villi, lymphatic channels

17. 3 types of mechanisms predisposing for
developing Hydrocephalus
1. Increased production (Communicating H)
2. Decreased absorption (Communicating H)
3. Obstruction (aqueduct – 3 mm long & 2 mm wide)
(Obstructive H / Non-Communicating H)

18. 1. Increased production of CSF
Tumours in the choroid plexus - rare

19. 2. Decreased absorption of
CSF
Obliteration of Arachnoid villi & cisterns:
Congenital: TORCH
Acquired: Meningitis
Blood
Leukemia

20. 3. Obstruction of CSF
Congenital:-
Aque ductal stenosis:
TORCH, malformations of aqueduct,
Aneurysmal dilatation of vein of Galen, X-linked
Arnold- Chiari malformation II:
Dandy-Walker syndrome:

21. Hydrocephalus - Obstructive
Acquired
Aque ductal gliosis
Meningitis, Bleeding (intraventricular - in
preterms), Mumps encephalitis
Posterior fossa tumours:
Medulloblastoma obstructing aqueduct

22. Clinical features –
Before AF close

23. Clinical features –
Before AF close
Big head
Big fontanalle (Normal at birth: 2.5 cms)
Widely placed sutures (>5 mm)
Broad forehead
Prominent subcutaneous veins
Sun-set eyes (dilated suprapineal recess impinges on the tectum,
midbrain, which controls eye movements)
Weakness of lower limbs (stretching and disruption of CS fibres
originating from the leg region of the motor cortex, while crossing over the
dilated ventricles)

25. Prominent subcutaneous
veins

26. Clinical features –
after AF closure - ICT
Headache, vomiting
Blurring of vision -stooping and bending
Bradycardia, increase in BP (Cushing’s triad –
ICT disturbs the vasomotor centre in Medulla)
6th
CN palsy (often unilateral)
Papilloedema
Transillumination (2.5cm & 1cm)- (when there
is massive dilatation of the ventricles or in Dandy-
Walker syndrome)

27. Clinical features –
after AF closure - ICT
Macewan sign
(crack pot sound - significant only after the AF & sutures
close)
Small occiput – Arnold Chiari
Prominent occiput – Dandy-walker

28. Diagnosis
1. History:-
Familial: X linked or AR Aqueductal stenosis
Prematurity
Intra uterine infection
Intracranial hemorrhage
Meningitis
Mumps Encephalitis (leads to aqueductal stenosis)
2. 0/E:
Café-au-lait patches (NC markers)
Spinal dysraphism (tufts of hair, lipoma, angioma)
Wide AF, wide sutures, sun set eye sign, LL weakness
Cranial bruit (AV Malformation of Galen)
Transillumination +: massive dilatation of ventricles; D. W. syndrome
Eye: Papillodema, chorioretinits

29. Diagnosis -Investigations
1. X-Ray skull:-
Infant:
Older child:
In long standing cases:

30. Diagnosis -Investigations
1. X-Ray skull:-
Infant: Calcification (IU infection)
Separated sutures
Older child: Thinning of the floor of the sella
Erosion of the posterior clinoids
In long standing cases:
Silver-beaten appearance
(an increase in convolution markings)

31. Diagnosis - Investigations
2. USG (through AF), CT scan & MRI:-
Dilatation of all ventricles: communicating type
3rd
ventricle dilatation & 4th
ventricle normal:
Aqueductal stenosis

32. Treatment – Supportive-
Control of ICP
1. Head elevated to 30 deg & in neutral
2. Control of temperature
3. Control of seizures
4. Maintain blood pressure
5. Analgesia & sedation

33. Treatment – Supportive-
Control of ICP
Hypertonic solutions:-
Mannitol or Oral glycerol
Passive hyperventilation:-
Decline of PCO2
Mild constriction of blood vessels in brain
Mild (10-30%) reduction of ICT

34. Treatment
For decreasing the production:-
Acetazolamide – temporary
For Obstruction and decreased absorption:-
Ventriculo Peritoneal shunt
Complication: Infection (Staph. Epid)
Obstruction

35. Prognosis
Depends on:-
the cause for ICT
the rate of increase in ICT
the presence of other developmental
abnormalities of brain
the time at which the treatment was initiated
(early or late)

36. Prognosis
Abnormalities observed in long term follow-
up are:
Developmental disabilities
Memory disturbances
Visual problems – strabismus, field defects, optic
atrophy
Accelerated pubertal development
Increased Gonadotrophin levels

37. To Sum UpTo Sum Up

38. THE END