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