causes and diagnosis of hydrocephalus

1. hydrocephalus
Hesham Ahmed

2. •Introduction
•definitions
•CSF physiology
•Causes
•Clinical picture
•Diagnostic tools
•Management

3. intro
 The brain tissue, cerebrospinal fluid (CSF), and
blood are the three intracranial compartments that
determine the size of the skull during infancy.
 Expansion of one compartment comes at the
expense of another in order to maintain volume and
pressure .
 The epidural, subdural, and subarachnoid spaces
may expand with blood or CSF fluid and significantly
affect cranial volume and the other intracranial
compartments.
 Less important factors contributing to head size
are the thickness of the skull bones and the rate of
their fusion.

4. Definitions
Hydrocephalus is an increase in the (CSF) volume within the ventricular
system with increased ICP independent of the actual head
circumference .
Ventriculomegaly: radiological appearance of increased ventricular
volume not necessarily implying increased pressure (e.g. could be due
to parenchymal atrophy).
Obstructive (non-communicating): obstruction to CSF flow in the
ventricular system before reaching the subarachnoid space.
Communicating: decreased absorption of CSF from arachnoid villi and
subarachnoid spaces; or increased CSF production (choroid plexus
papilloma).

5. External hydrocephalus: enlarged subarachnoid spaces, e.g. around
the frontal lobes, without ventricular dilation, normal in early infancy.
In
ambiguous cases may need ICP monitoring to clarify whether
pressure
truly raised.
Congenital hydrocephalus is one of the most common CNS congenital
anomalies
The incidence of congenital hydrocephalus is estimated as 3 per1,000
live births.
Normal pressure hydrocephalus: ventricular dilatation, no
parenchymal atrophy and normal CSF pressure with chronic
symptoms (gait disturbance, cognitive deterioration and
incontinence). Not known to occur in children.

6. 1. Physiology of CSF production and absorption
1. Production of CSF: by the choroid plexus of lateral
ventricles
2. Pathway of CSF flow
1. From lateral ventricles to the 3rd ventricle through the
foramen of Monro.
2. From the 3rd ventricle to the 4th ventricle through the
aqueduct of Sylvius.
3. Out of the ventricular system: from the 4th ventricle to
spinal subarachnoid spaces through the foramen of Magendie
or to the basal cisterns through two lateral foramina of
Luschka
3. Site of CSF resorption into the venous system:
through the superior sagittal sinus via arachnoid granulations

8. 2. Patho-physiologic consequences of hydrocephalus
1. Hydrocephalus-induced damage (atrophy) is dependent on:
1. The rate and magnitude of ventricular dilatation
2. The proximity to the ventricle
3. The developmental stage
2. Developmental processes including myelin production can
be impaired.
3. The potential for reversal of damage by shunting
diminishes as the duration and severity of hydrocephalus
increase.

9. Causes of hydrocephalus
1. Acquired hydrocephalus
a)Inflammatory
Subarachnoid hemorrhage or infection scar (dysfunctional
subarachnoid space)
Intraventricular hemorrhage or infection scar (ventricular
obstruction)
b)Neoplasm
1. Parenchymal brain tumor: mass effect(ventricular
obstruction)
2. Spinal cord tumor: altered CSF composition(dysfunctional
subarachnoid space)
3. Disseminated tumor: tumors with meningeal infiltration
(dysfunctional subarachnoid space)
4. Choroid plexus tumor: altered CSF composition
(ventricular obstruction)
(CSF overproduction)

10. c)Vascular
1.Vascular malformation:
vein of Galen malformation
arteriovenous malformation
2. Disordered cerebral venous
function:
extrinsic obstruction : skeletal
dysplasia
intrinsic obstruction : VST

11. 2:congenital
1. Tumors blocking CSF pathway
choroid plexus papilloma
2. CNS malformations/syndromes
1. Congenital atresia of the foramina ( Monro , Magendie, or
Luschka)
2. Dandy-Walker syndrome
3. Aqueduct stenosis
4. X-linked hydrocephalus (Severe MR And deformity of the
thumb)
5. Chiari II malformation
6. Cerebellar agenesis
7. Neural tube defects :Meningomyelocele/Encephalocele
8.Destructive lesions :Hydranencephaly /Porencephaly

12. 3. Chromosome abnormalities
Trisomy 13 /18
4. Skeletal dysplasia
Achondroplasia
Craniosynostosis (Crouzon or Apert syndromes)
Fanconi anemia
MPS(Hurler and Hunter syndromes)
5. Congenital Infections
6. Vascular malformation
7. In utero IVH
8.Genetic
Noonan’s syndrome, Costello’s syndrome,NF1
VACTERL-H anomalies plus hydrocephalus
Walker-Warburg syndrome/Smith-Lemli-Opitz syndrome/Meckel
syndrome

13. Clinical picture

14. Early infancy
• Accelerated head growth; OFC crossing the centiles with Increment > 1 cm /week in
neonates.
• Bulging fontanelle.
• Cranial sutures widened.
• Prominent scalp veins.
• Sun-setting eyes.
• Irritability, poor feeding.
• Delayed development
Later childhood
• Macrocephaly, may be an isolated finding in arrested hydrocephalus.
• Headache.
• Vomiting.
• Lethargy and somnolence.
• Visual disturbance

15. Handicaps resulting directly from hydrocephalus
1. Impaired mobility and ambulation (cerebral palsy)
2. Impaired cognition (mental delay, behavior)
3. Sensory deficits (vision, hearing)
4. Endocrine dysfunction (growth, puberty ,weight
imbalance, fertility)
5. Epilepsy
6. Depression
7.chronic headache

16. clinical features of hydrocephalus in the non-shunted group
1. Symptoms
Asymptomatic (49%)
Headache or irritability (33%)
Vomiting (16%)
2. Signs
Inappropriately increasing occipitofrontal circumference (76%)
Tense anterior fontanelle (65%)
Splayed sutures (39%)
Scalp vein distension (33%)
Sunsetting or loss of upward gaze (22%)
Neck retraction or rigidity (14%)

17. clinical features of hydrocephalus in the shunted group
1. Symptoms
• 1. Vomiting
• 2. Drowsiness or lethargy
• 3. Headache
• 4. Behavioral change (including irritability)
• 5. Anorexia
2. Signs
• 1. No clinical signs
• 2. Decreased conscious level
• 3. Acute strabismus
• 4. Neck retraction
• 5. Distended retinal veins

18. Diagnostic Investigations

19. Antenatal detected hydrocephalus
• Severity of fetal ventriculomegaly defined by lateral
ventricle width at 20 weeks gestation:
10–15 mm = mild to moderate
> 15 mm = severe
•Actions
Detailed scan to identify further anomalies.
Fetal MRI to assess cerebral architecture.
Amniocentesis offered for karyotype and NTD .
TORCH screen .
Parental counselling.
Termination of pregnancy according to severity.
IU interventions is under trials

20. neuroimaging

21. Cranial sonography
Ventriculomegaly Intraventricular hemorrhage
CT scans
Ventriculomegaly/Cerebral edema /Mass lesions (cysts or tumors)
MRI
1. Ventriculomegaly.
2. Mass lesions.
3. Associated brain anomalies :
Agenesis of the corpus callosum
Chiari malformations
Disorders of neuronal migration
Vascular malformations
4.Ischemic changes of brain tissue

22. Prenatal ultrasound at 33 weeks showing markedly
dilated lateral ventricles

23. Aqueduct stenosis. T1-weighted sagittal MRI shows noncommunicating hydrocephalus
secondary to stenosis of the aqueduct of Sylvius (arrow). The lateral and third ventricles
are enlarged, with a normal-sized fourth ventricle. An arachnoid cyst is inferior to the
cerebellum

24. MRI of the brain of a patient showing
hydrocephalus due to aqueduct stenosis

25. Dandy-Walker malformation. T1-weighted sagittal MRI shows cystic
transformation of the fourth ventricle with enlargement of the posterior fossa and
dysgenesis of the inferior cerebellar vermis.

26. Sagittal T1-weighted MRI Dandy–Walker
malformation. The arrow denotes the large,
retro cerebellar CSF collection (cyst). This child also has agenesis of the
corpus callosum.

27. Chiari II malformation. T1-weighted sagittal MRI shows partial agenesis of the
corpus callosum
and herniation of the cerebellum below the foramen magnum, and kinking of the
medulla.

28. management

29. Shunts
The principle of shunting is to establish a communication between the CSF and
a drainage cavity.
shunts are not perfect and that all alternatives to shunting should be considered
first.
A (VP) shunt is used most commonly. The lateral ventricle is the usual proximal
location. The advantage of this shunt is that the need to lengthen the catheter
with growth may be avoided by using a long peritoneal catheter.
A (VA) shunt shifts CSF through the jugular vein and superior vena cava into the
right cardiac atrium. It is used when the patient has abdominal abnormalities
but requires repeated lengthening in a growing child.
A ventriculo-pleural shunt is considered 2nd line. It is used if other shunt types
are CI.
A lumbo-peritoneal shunt is used only for communicating hydrocephalus or
pseudotumor cerebri.

31. Major complication associated with shunt
 80% of children with shunts suffer at least one and usually several
malfunctions necessitating hospitalization
1. Shunt obstruction
2. Valve malfunction
3. Disconnection
4. Hematoma
5. Over drainage
6. Outgrown shunt
7. Shunt fracture
8. Shunt-related infections, most often caused by Staphylococcus aureus
9. Signs of increased ICP

32. 10. Abdominal complications
Peritonitis
Perforation of an abdominal organ
Peritoneal cysts
Development of hydroceles in boys
CSF ascites
11. Seizures
12. Allergic reaction to material
13.Shunt migraine: may be very resistant to pharmacological therapy

33. Infection
• Typically due to colonization of shunt with skin flora during
insertion.
• Risk much higher with post-operative CSF leak.
• May be difficult to differentiate from (UTI).
• Discuss with the neurosurgical team before tapping the shunt .
Treatment
• requires a period of shunt externalization (allowing the
distal end of the shunt to drain into an external reservoir, rather than
the peritoneum)
• prolonged intravenous antibiotics and shunt replacement once CSF
indices indicate eradication of the infection.

34. Lumbar puncture
Repeat (LPs) can be performed for cases of hydrocephalus after IVH,
since this condition can resolve spontaneously.
LPs can be performed only in cases of communicating hydrocephalus.
Alternatives to shunting
Choroid plexus coagulation may be effective in cases of CSF over-
production.
Opening of a stenosed aqueduct has in the case of tumors.
In cases where a tumor is the cause, removal cures the hydrocephalus
in 80%.
Endoscopic fenestration of the floor of the third ventricle establishes
an alternative route for CSF toward the subarachnoid space.
It can be used especially with aqueduct stenosis.

35. medical
Medication as treatment for hydrocephalus is controversial.
 It should be used only as a temporary measure for posthemorrhagic
hydrocephalus in preterm neonates, or when shunting is not possible.
Acetazolamide (CAI) and furosemide treat posthemorrhagic
hydrocephalus in neonates. Both are diuretics that also appear to
decrease secretion of CSF at the level of the choroid plexus. ACZ can be
used alone or in conjunction with FUR.
The combination enhances efficacy of ACZ in decreasing CSF secretion
but increases risk of nephrocalcinosis.
Medical treatment is not effective in long-term treatment thus should
be used only as a temporizing measure.

36. Thank you