Spina bifida is a congenital malformation that occurs during the first month of gestation and can cause physical and intellectual disabilities. It is included in the group of neural tube defects (NTDs). The neural tube is a narrow tube that forms in the first 25-28 days of pregnancy. The upper part becomes the brain of the embryo and the rest turns into the spinal cord. Spina bifida occurs when the bones of the spine do not close properly and the medulla and the meninges (membranes that surround the brain and spinal cord) are left unprotected, affecting their nerve fibres.

Types of spina bifida

• Myelomeningocele. This is the most common and most serious type of spina bifida. It occurs when a cyst or sac of cerebrospinal fluid containing part of the nerves and spinal cord comes through an opening in the baby’s spine, causing partial or complete paralysis of the parts of the body located below the spinal opening. It can lead to difficulties with walking and urinary and bowel dysfunction.
• Meningocele. This type of spina bifida differs from myelomeningocele in that the sac of cerebrospinal fluid that comes through an opening in the baby’s spine does not include the spinal cord. It leads to minor neurological sequelae that are very similar to lipomeningocele.
• Lipomeningocele. In this type of spina bifida, the cyst that comes through the opening in the baby’s spine contains fat. This fat penetrates the spinal canal and can cause spinal cord compression. Some patients may present few or no symptoms; other patients may have incomplete paralysis with urinary and bowel dysfunction.
• Spina bifida occulta. This is the mildest form and does not usually generate disability. It usually goes unnoticed. The spine has an opening, but no cyst or sac of fluid comes through. Nerves and the spinal cord are usually in a normal state.

The severity of this malformation is based on the fact that it affects the three main systems of the human body: the central nervous system, the musculoskeletal system and the genitourinary system.

Most frequent consequences of spina bifida

• Loss of mobility and sensitivity
• Sphincter incontinence
• Cognitive and learning difficulties
• Other disorders, such as visual problems (strabismus), bone fragility or hip dislocation

In most cases, spina bifida produces hydrocephalus, which is the accumulation of an excessive volume of the fluid that protects brain tissue. Very often, a ventriculoperitoneal shunt valve must be fitted to treat hydrocephalus.