Intelligence Quotient in Patients with Myelomeningocele: A Review

It has been proposed that hydrocephalus in children with myelomeningocele (MMC) can indicate a low intelligence quotient (IQ). Others have argued that it is not the mere presence of hydrocephalus but the superimposition of cerebrospinal fluid (CSF) infections, multiple shunt procedures, and other CNS complications that lead to the lowering of IQ in these patients. In this paper, we review the literature to clarify the information about IQ in patients with MMC and whether it changes after infections and shunt procedures. We have also considered the other factors that could be involved in the IQ development of these patients and the differences revealed by the brain imaging of individuals with MMC. The consensus remains that patients with MMC, with or without complications, tend to have a lower IQ than those without MMC. Hydrocephalus appears to decrease the IQ further in MMC patients. Some have proposed that prenatal repair of the MMC lesion reduces the need for ventricular shunting after birth, thus decreasing the risk of shunt complications such as a CNS infection, which can have a negative effect on IQ. More studies are needed to assess other risk factors (apart from folate deficiency) and genetic factors that could contribute to the development of MMC and their possible effects on patient IQ.