Pediatric neurosurgeons at Children’s Memorial Hospital, Chicago, review their long-term experience and the evolution of the etiology, diagnosis and management of patients born with myelomeningocele (MM) in 1975-1979 and followed for 25 years in a multi-disciplinary spina bifida clinic. Genetic factors and folic acid deficiency are implicated in the etiology of neural tube defects. Supplementation with folic acid has significantly reduced but not eliminated the risk of MM. The prevalence of spina bifida worldwide ranges from 0.17 to 6.39/1000 live births. Incidence varies with gender (girls > boys), ethnicity (increased in Hispanic and Northern Chinese), age (< 20 and >30 years more susceptible), geographic areas (in N America, higher in east and south cf west), and nutritional factors. Incidence was declining before use of folic acid, but following periconceptual multi-vitamin supplementation, a significant decrease occurred (MRC, 1991). Since 1992, US center for disease control recommends 400 mcg folic acid daily for women of reproductive age, and by 1998, fortification of all grain products. Incidence in US decreased 22.9%, when comparing period 1995-6 to 1998-9. Elective termination of pregnancy following prenatal diagnosis by serum alpha-fetoprotein screening and ultrasonography is also responsible for a declining incidence. The “lemon” sign and “banana” sign of Chiari II malformation are present on ultrasound after the 12th postmenstrual week. Fetal surgery for MM may arrest leakage of spinal fluid and prevent or reverse Chiari II malformation and hydrocephalus. Selective treatment for MM, as advocated by some authorities in the 1970, was generally not followed in the US, and today most centers treat all viable newborns aggressively without selection. The outcome of in utero closure awaits evaluation by the management of MM (MOM) study group.
Long-term outcome of non-selective treatment of 118 infants with MM born 1975-79, and followed at Children’s Memorial Hospital, compared to a cohort born in 2000-2005, found a decline in the number of live births with MM: 16-32/year in the older cohort vs 1-13/year in the younger cohort of 40 children. The overall mortality in the older cohort at 20-25 year follow-up was 24%, the majority of deaths (18/28) occurring in infancy and pre-school years, secondary to hindbrain dysfunction or shunt malfunction. In the younger cohort, none have died during infancy and early childhood. Shunt placement has decreased from 86% in the older 1975-79 group to 65% in children born 2000-2005. (In a 2008 report from Great Ormond Street Hospital, London, UK, the rate of shunt placement is now 51%). The increased survival rate presents a challenge for pediatric and adult healthcare providers. [1]
COMMENT. As with many congenital or early childhood chronic nervous system diseases, the transition period from pediatric to adult care poses problems. Pediatric subspecialists are frequently unfamiliar with adult care. Pediatric clinics are often geographically separated from clinics for adults. Patients have difficulty separating from a team that has cared for them for two decades. The authors comment that shunt malfunction is a primary consideration in long-term care of MM, and adult colleagues need to become familiar with this problem. Learning and attention deficit disorders are additional troublesome complications of MM that require specialized treatment.