Table 1.

Aetiology of hydrocephalus

Aetiology	Total (n = 100)	1A Symptomatic (n = 9)	1B Non-symptomatic (n = 10)	2 No upgrade (n = 81)
Myelomeningocele	37 (37%)	1 (11.1%)	2 (20%)	34 (42%)
Aqueductal stenosis	13 (13%)	2 (22.2%)	1 (10%)	10 (12.3%)
Post-infectious	5 (5%)	0	0	5 (6.2%)
IVH of prematurity	17 (17%)	3 (33.3%)	2 (20%)	12 (14.8%)
Congenital communicating	3 (3%)	0	1 (10%)	2 (2.5%)
Posterior fossa cyst	6 (6%)	1 (11.1%)	2 (20%)	3 (3.7%)
Tumour (non-midbrain)	3 (3%)	0	0	3 (3.7%)
Other	16 (16%)	2 (22.2%)	2 (20%)	12 (14.8%)