3. HydrocephalusHydrocephalus
ïAbnormal dilatation of the cerebral
ventricular system
ïHydrocephalus should be differentiated from
disorders producing ventricular enlargement
secondary to cerebral atrophy.
ïClassified into :
1. Communicating Hydrocephalus
2. Non communicating Hydrocephalus
4. Characterisics of HydrocephalusCharacterisics of Hydrocephalus
ïVentricular enlargement disproportionate to
the degree of sulcal widening
ïEnlagement of temporal horne
ïPeriventricular fluid 2ry to transependymal
CSF permeation
ïEnlarged 3rd
ventricle with large suprapineal
and chiasmatic receses
ïIn children < 2 years the head circumference
is often the best distinguishing feature
between hydrocephalus and atrophy.
7. Non-Communicating HydrocephalusNon-Communicating Hydrocephalus
(Intraventricular obstruction)(Intraventricular obstruction)
ïVentricular dilatation caused by
intraventricular obstruction at or above the
the outlet foramina of the 4th
ventricle
ïCauses:
1. Lateral ventricle
2. Foramen of Monro
3. 3rd
ventricle
4. Aqueduct of sylvius
5. 4th
ventricle
8. Lateral Ventriclar causes:Lateral Ventriclar causes:
1. Intrinsic tumor: ependymoma
2. Ventriculitis: due to intraventricular
adhesions
3. Extraventricular Tumour: mass effect
from large parenchymal mass