What Is It?
A meningocele is a form of spina bifida. It is a congenital malformation that arises from an error in the normal development of the central nervous system, particularly the spinal cord and spine. It is an out-pouching of the coverings of the spinal cord that results in a defect in the bone and soft-tissue coverings of the back part of the spine. Therefore, this sac filled with cerebrospinal fluid can lead to a bulging mass on the back. The malformation does not include any malformation of the spinal cord itself or any of the spinal nerves.
The meninges are the coverings of the brain and spinal cord, consisting of three layers, the dura mater, the arachnoid membrane and the pia mater, from outside to in. This malformation is due to the abnormal development of the outermost coverings of the spinal cord, including the arachnoid, dura and the outer bony and soft tissue parts of the spine. Normally in development, the nervous system develops from a plate of cells that folds to become a tube, the neural tube. If the lower end of the tube does not close normally, it can lead to various forms of spina bifida, including a meningocele.
A meningocele represents a moderate form of spina bifida. The most severe form is a myelomeningocele which includes involvement of the spinal cord. The most mild form is spina bifida occulta, which does not involve any of the nervous system structures or the meninges, just the bony spine in the lower back.
The most common location for this malformation is the lumbar spine, the lower back.
What Types of Symptoms Are Typical?
Because, by definition, a meningocele does not include any malformation of the spinal cord, typically there are not significant neurological symptoms of this malformation. The typical presentation is a bulging sac on the lower back in a newborn child. This can be associated with some deformity of the spine. Generally, if the spinal cord and/or spinal nerves are involved and cause neurological symptoms in the legs, this should be classified as a myelomeningocele
, not a meningocele, which only includes the coverings of the spinal cord, not the cord itself.
Therefore, the primary problems with this deformity are cosmetic. However, if large, the sac on the back can interfere with normal function and development and can be quite a stigmatizing malformation. In rare cases when the skin over the sac is not fully developed, the sac can have a tendency to leak or rupture, leading to leakage of cerebrospinal fluid. This can lead to headache and, more importantly, infection such as meningitis. In these cases the diagnosis and treatment is much more urgent and a medical necessity.
How Is The Diagnosis Typically Made?
Most meningocele are noticeable at birth. This generally leads to some form of imaging study such as a CT scan
or MRI scan
. These, particularly the MRI, can help to identify which parts of the spinal column are involved in the malformation and distinguish it from other forms of spina bifida such as a myelomeningocele
. If any of the spinal cord and spinal nerves are involved in the sac, it is termed a myelomeningocele
What Are Some Common Treatments?
Most cases of meningocele are recommended for treatment as soon after birth as possible. In the case of a sac which is leaking fluid, the treatment is more urgent. Generally, treatment includes a surgical procedure to close and remove the bulging sac of meninges and to re-construct the soft-tissue covering of the back.
Each patient is different and these malformations vary in size and location somewhat. Therefore, each individual patient's treatment plan should be discussed with their own personal physicians.
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This site is not intended to offer medical advice. Every patient is different, and only your personal physician can help to counsel you about what is best for your situation. What we offer is general reference information about various disorders and treatments for your education.