Hydrocephalus Slide effacement

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Hydrocephalus Slide  effacement Powered By Docstoc

          11TH JUNE 2010
Definition, Classification and
                MR. M.T. A. SATTAR
               BEAUMONT HOSPITAL
               O.L.H.S.C - CRUMLIN.
and its treatment
Definition & Classification
• Hydrocephalus is a pathophysiological condition of diverse aetiology with
  common background mechanisms of disturbed i) CSF production ii)
  circulation or iii) absorbtion. These factors can contribute independently or
  in combination to produce hydrocephalus.
• Excess CSF in the ventricles and/or the subarachnoid space is a common
  finding but not a prerequisite
• There are two main functional subdivisions of hydrocephalus:
• 1- Obstructive hydrocephalus :
• Blockage of the CSF circulation proximal to arachnoid granulations
  leading to enlargement of the ventricles proximal to the block.
• 2- Communicating hydrocephalus:
• Obstruction of CSF circulation at the arachnoid granulations.
Definition & Classification
These functional subdivisions can be etiologically classified:
  Obstructive HCP             Communicating HCP
  Congenital                  Congenital
  Aqueduct stenosis           Arnold Chiari malformation
  Dandy walker cyst           Encephalocele
  Vascular malformations      Skull base deformity

  Acquired                    Àcquired
  Tumours                    Infections
  Other mass lesions         Haemorrhage
  Ventricular scarring       Venous hypertension
                             Overproduction of CSF
Clinical Presentation (Infants)
   •   head enlargement, poor feeding, vomiting
   •   reduced activity, drowsiness
   •   tense fontanelle
   •   dilated scalp veins
   •   sunset sign
Late sign in HCP.

                    Sun setting eyes.
CT appearances

• Large ventricles
   – Rounded third
   – Temporal horns dilated
   – Transependymal migration of fluid
     (periventricular lucency)
   – Sulcal effacement
CT appearances

• Large ventricles
   – Rounded third
   – Temporal horns dilated
   – Transependymal migration of fluid
     (periventricular lucency)
   – Sulcal effacement
T 2 axial MRI showing
hydrocephalus with PVL.

                          Axial MRI

• External ventricular drain (usually an emergency)
• Ventricular tap (infants) or lumbar puncture
• Shunts
   –   Ventriculo-atrial
   –   ventriculo-peritoneal
   –   Ventriculo-pleural
   –   Lumbo-peritoneal (only if communicating)
• Third ventriculostomy
External ventricular drain

• Insertion point
• Tunnelled to prevent infection
• Can be used for treatment and measuring of pressure
Management - long-term
•   VA or VP shunt (LP shunt)
•   removal of tumour if causing hydrocephalus
•   third ventriculostomy if possible
•   medical treatment (rare) - diuretic (acetazolamide,

• Commonest is VP
• Come at different pressure settings (we use medium
  pressure most commonly)
   – Low           1-4 mmHg
   – Medium        4-8 mmHg
   – High          8-13 mmHg
• Programmable (30-210 mm CSF pressure)
• Mostly into posterior horn of lateral ventricle
Programmable shunt
Complications of Shunts
•   Infection.
•   Shunt blockage (Proximal, Valve , Distal ).
•   Overdrainage.
•   Fracture or disconnection.
•   Migration.
•   Malposition.
•   Isolation ( trapping of the ventricles).
•   Intracranial haemorrhage.
•   Viscous perforation.
Causes of malfunction
Chronic subdural
collection secondary to
over drainage.

                          Axial CT
Investigation of shunt malfunction

•   Clinical
•   Radiological
•   Shunt tap
•   ICP monitoring
•   Time
•   Surgery
Common clinical features

Infant                 Older child
• Bulging fontanelle   • Headache
• ↑ OFC                • Vomiting
• Wound                • ↓ LOC
• ↓ LOC                • Papilloedema
• Vomiting             • Wound
• Irritability         • Meningism
• papilloedema         • School
• abdominal            • Unable to depress reservoir
• ↓ milestones

•   Decreased level of consciousness
•   Papilloedema
•   Abdominal swelling, peritonitis
•   Wound erythema/CSF leak
•   Unable to depress reservoir (depends)
•   Milestones/school performance
Cranial CT scan

   • Baseline CT when well
   • Imaging signs of shunt malfunction
      –   Increased ventricular size
      –   Periventricular lucency
      –   Effacement of sulci
      –   Basal cistern obliteration
False negatives
1/3 of blocked CSF shunts
will have no change on CT
Navigation Technology (Axiem)
ICP monitoring
1. Mum is always right

2. Mum is always right

3. Mum is always right
The best shunt is no shunt

Endoscopic third ventriculostomy


1. non-communicating hydrocephalus
  (sufficient CSF reabsorption capacity)

2. Ventricles large enough to navigate
ETV complications

•   Basilar artery injury
•   Venous haemorrhage
•   Epilepsy
•   Infection
•   Forniceal/hypothalamic injury
•   CSF or wound leak
•   Late sudden death
ETV ‘survival’ in accepted indications
Causes in neonates

• Intraventricular haemorrhage

• Myelomeningocele
Hydrocephalus post-IVH
Hydrocephalus post-IVH

   • Factors affecting neurosurgical
      –   Clinical symptoms/signs
      –   Size/weight
      –   Blood load
      –   Hydrocephalus – progression
      –   Co-morbidities
Treatment algorithms

• No hydrocephalus
Treatment algorithms

• No hydrocephalus
• ‘Stable’ hydrocephalus
Treatment algorithms

• No hydrocephalus
• ‘Stable’ hydrocephalus
• ‘Progressive’ hydrocephalus
   – Shunting
      • Relentless                -is a shunt possible?
      • Self limiting   -is shunting necessary?
Temporising measures

   • Lumbar punctures
   • Ventricular taps
   • Ventricular access
Revision rates (UKSR)

        Primary Insertions   Revisions
Infection rates

         Primary Insertions   Revisions
Fetal endoscopy
Fetal Ventriculomegaly

•   Diagnosis of Fetal Cerebral Ventriculomegaly is made when one or both
    lateral ventricles measures more than 10 mm.

    Mild FVM     : 10 – 12 mm
    Moderate FVM : 12.1 – 15 mm
    Severe FVM   : 15 mm +

    Counselling of parents

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Description: Hydrocephalus Slide effacement