Spina Bifida Cystica (SBC) is the commonest of the spinal dysraphic disorders in Africa, like the rest of the world. However, experience and reports in the literature set Africa apart from other areas in certain respects. Thus, SBC is less frequent in African than in Caucasians. African males are more affected than females; in Europe, female patients outnumber males. The European criteria for selecting (or rejecting patients to be actively treated cannot be applied wholesale to Africa where social factors dilute or over-ride those criteria). The disease has unique psychosocial and cultural connotations in Africa where its long term problems are awaiting study. Finally the use of folic acid in its prevention already established in many parts of the world is still crying for adoption in Africa.
La spina bifida kystique est l’anomalie vertebrale la plus courante en Afrique, comme ailleurs dans le monde Cependant, l’experience ainsi que l’analyse de la litterature montrent qu’en Afrique, elle presente certaines particularites: une frequence moindre chez l’africain qe chez le caucasien, une predominance chez les hommes. Les criteres europeens de selection des patients a traiter ne peuvent pas etre appliques globalement a l’Afrique ou les facteurs sociaux modifient ces criteres en les attenuant ou en les exagerant. La maladie a une connotatin culturelie et psychologique propre ou l’etude de ses consequences a long terme n’est pas encore entreprise. En outre, l’utilisation de l’acide folique pour la prevention est deja en place dans de nombreuses regions du monde, mais toujours inexistante en Afrique.
Keywords : Spina bifida cystica, Africa
Spina bifida cystica (SBC) is one of the congenital lesions which together with spina bifida occulta, anencephaly and encephalocele make up the neural tube defects. A number of genetic and environmental factors conspire to cause neural tube opening leading to spinal dysraphism, one of the most serious developmental disabilities affecting the craniospinal axis.
The reported incidence of SBC in the African is less than 1 per 1000 deliveries. In Durban, South Africa (18) and at the University College Hospital, Ibadan, Nigeria an incidence of 0.46 per 1000 was recorded for SBC among all live births (7). In 1969, Gupta (17) reported an incidence of 0.94 per 1000 total deliveries (live and stillbirths). These figures are much lower than the 3 per 1000 live births encountered in the United Kingdom (14) and the 4 per 1000 among all deliveries in the South Wales (20). It thus appears that SBC is less frequent in the African than in the Caucasian.
The first reports of central nervous system malformation in Africa were based on the prevalence noted among deliveries in general hospitals in 1966 in Cairo in North Africa (19) and in 1968 in Lagos, Nigeria, West Africa (21). The lesions found in these studies, in order of frequency were anencephaly, hydrocephalus and SBC.
With the establishment of neurosurgical and neurological units on the African continent, hospital surveys of large representative series of congenital malformation of the central nervous system started to emerge. In the series from East Africa (34) and from francophone (10) and anglophone (6, 29) West African countries, SBC ranked second to hydrocephalus. In Zimbabwe, SBC was the commonest CNS malformation encountered (22)
In Africa, like the rest of the world, it is the commonest member of the family of spinal dysraphic disorders which include spina bifida occulta, pseudotail, lumbosacral lipoma and anterior sacral meningocele (4).
Many pathological varieties of SBC are known. The simplest form, the meningocele in which the cyst contains only CSF without myelin or nerve roots but with intact skin and in which the patients has intact sphincter and normal limbs, is relatively rare. Meningocele in Africa accounts for between 2 percent (1) and 10 percent of SBC. Myeloceles in which the cyst contains cord and nerve roots, are, by contrast, common. Henry and Michel (18) reported 27 meningoceles and 166 myeloceles in West Africans subdivided myeloceles into myelomeningoceles in which the sac contains nerve roots only and meningomyeloceles in which cord and nerve roots lie in the cyst.
Bailey (11) reported the rare case of double meningocele in a Ugandan child; in Malawi we have encountered a patient with lumbosacral SBC as well as a high dorsal spina bifida occulta (5).
Most reports in Africa show male predominance over females in contrast to the Caucasian experience whereby females outnumber males in a ratio of 2 to 1 (32). At Ibadan, Nigeria, the male:female ratio was 1.2 to 1 (7).
As in other parts of the world SBC in Africa is a syndrome comprising the cyst, hydrocephalus, sphincter disturbance and neuromuscular imbalance manifesting as varying and various degrees of lower limb deformity.
The incidence of preoperative hydrocephalus in Africa varies from 30 to 42 percent (3) as compared to the 80 to 90 percent reported in western literature (35). The difference is probably due to closer patient follow-up and better documentation of cases in centres outside Africa. Nevertheless, like everywhere else, the highest incidence of hydrocephalus occurs in thoracic lesions. Children who came late to hospital (and many do so in Africa) show reduced incidence of hydrocephalus (4).
Early closure of SBC within 24 to 48 hours of birth, as practised in many parts of the developed world, is not always possible in Africa due to late presentation in hospitals. As a result, the management of the disease in Africa is bedevilled by cyst infection and subsequent meningitis, late convulsions and mental retardation (9). In children presenting in the first week of life, staphylococcus aureus is the dominant infective organism; in other children presenting late, pseudomonas aeruginosa and coliforms predominate (27).
In 1971 Lorber (23) revolutionised the treatment of SBC by suggesting criteria for NOT operating on affected children. The criteria include gross hydrocephalus at birth (maximum head circumference 2cm or more above the 90th percentile in relation to birth weight); severe neuromuscular imbalance leading to paraplegia; thoracolumbar lesions; associated extra – CNS anomalies such as Down’s syndrome and cyanotic heart disease.
In Britain, such children who are selected to die, in a form of « active euthanasia » (26), are kept on sedation and given food and water on demand.
Inspite of the wide acceptance in paediatric circles all over the world, Lorber’s criteria have some limitations in realistic practice and application within Africa. Firstly, if adopted in Africa, Lorber’s strictures will exclude almost eighty percent of children with SBC from surgery (27). Secondly, the criteria did not take into cognisance the not uncommon situation when parents press for surgical treatment of SBC in their children, even when Lorber’s criteria for rejection are overwhelming (33). Mezue and Eze (27) painted a poignant picture of this social scenario in our African setting where parents will do anything for their child, especially the male, and where a visible unsightly defect, like the cyst of SBC, is believed to be capable of reincarnation if the afflicted child is allowed to die with the cyst unremoved. In parts of Africa, the deformed child is a pariah, unfit to receive the dignity of a naming ceremony (2) or the ritual of circumcision.
The tendency therefore is to operate on most or all children, except where there are strong and compelling contraindications (30). Post operative gain is not dramatic. In Nigeria, 40 percent of limb paralysis and urinary incontinence show improvement (30); in South Africa, children with mild to moderate paralysis learn to walk (18). Surgery has even been offered to improve walking through hip stability in children with mid-lumbar myelomenignocele in Cape Town, South Africa (15).
Hydrocephalus which occurs in about two thirds of children with SBC poses real problems. Most cases of the associated hydrocephalus tend to arrest spontaneously, but in about 10 percent of cases, clinical hydrocephalus develops after closure of the SBC. Shunting procedures are more often used elsewhere than in Africa. McLone (26) reported that about 90 percent of children with SBC will require shunting procedure for the associated hydrocephalus. Here in Africa, shunt procedure is offered to children with stridor (8) or those with rapidly progressive head enlargement.
The treatment of SBC does not, and should not, end with the operative repair of the cyst or placement of shunt for the associated hydrocephalus. The child with SBC puts stains and stresses, on the family and the disease has socio-cultural undertones which has been well orchestrated in the West but only occasionally studied in Africa. One such report from Nigeria (31 ) found that the families of children with SBC had to undertake difficult distant journeys to hospitals, spanning hundreds of kilometres, the commuters being mostly mothers unaccompanied by their husbands or a senior relative. The disease is attributed to witchcraft or the evil spirit cast on mothers during their pregnancy. When the gains of surgery are undramatic, as they often are, or the early hopes of hospital treatment have become stultified, clinic attendance stops.
The children are then kept at home, social stigmata to the clan who are considered better dead than alive. These findings from Nigeria, some in fainter, others in bolder relief, apply to most parts of developing Africa. Clearly more information is needed on the long-term problems of the African child with SBC (31).
Prevention on neural tube defects appears the best policy of management of SBC in Africa. It has been shown in a United Kingdom medical Research Council Study that 4 mg per day of folic acid prevented about 75 percent of neural tube defects (24, 37). Women planning pregnancy have been advised to take 400 micrograms of folic acid a day (36). They should also eat more folate-rich foodstuffs, such as vegetables like Brussels sprouts, spinach and green beans, fruits like orange and orange juice and some cereals and cereal products (25). Similar recommendations have been made in Hungary (13) and in the United States of America (12). These simple measures, tested and tried and found to be useful, should be more widely adopted in Africa to prevent SBC and its ravages and miseries to the patient, his or her family and the society.