Major Malformations of the Central Nervous System as seen at The University Teaching Hospital, Ilorin.

Abstract

Background: The pattern of central nervous system (CNS) malformations seen at the University Teaching Hospital, Ilorin in the middle belt of Nigeria may be different from that seen in southern Nigeria and elsewhere.

Objectives: To present the major types of CNS malformations encountered in our centre over a five-year period.

Methods: A prospective study of all cases of CNS malformations seen on the neonatal and children's wards over a period of five years (2000-2005) at the University of Ilorin Teaching Hospital, Ilorin, was carried out. Diagnosis of the malformations was based on detailed history, clinical, as well as neurological and radiological evaluations. The data obtained were entered onto a proforma during hospitalization and follow-up, and were later analysed.

Results: One hundred and thirty five children (76 males and 59 females) were seen during the period. Spina bifida cystica (SBC) was the commonest among eight major malformations of the CNS encountered, accounting for 61 (45.2 percent) in the 135 children. The commonest (73.8 percent) form, a closed myelomeningocoele occurred in isolation in 30 cases and co existed with hydrocephalus in 15 other infants suspected to have Arnold Chiari type 2 malformation. SBC was most frequently located over the lumbosacral (74 percent) segment of the spine. The death of three children who developed meningitis or ventriculitis following rupture of myelomeningocoeles, accounted for the postoperative mortality rate of 6.7 percent among the infants with spina bifida. Hydrocephalus, the second commonest anomaly (50; 37 percent) was largely due to aqueduct stenosis (68 percent). Many of the affected infants presented late with grotesque head enlargement and varying degrees of visual failure. Death following shunting occurred in two children, a surgical mortality rate of 5.4 percent. Encephalocoele which was predominantly occipital (91.7 percent) constituted 8.9 percent of the total, while craniosynostosis (five cases), subgaleal inclusion cyst (three), microcephaly (two), porencephaly (one) and hydranencephaly (one) constituted less common anomalies. Of the 103 (76.3 percent) children who underwent surgical intervention, six died, resulting in an overall surgical mortality rate of 5.8 percent.

Conclusions: The commonest central nervous system malformation encountered in this centre was a spina bifida cystica followed by hydrocephalus. Parental socioeconomic status militated against standard management of many children with CNS malformations in this series.