WHY DOES HYDROCEPHALUS ALMOST ALWAYS COEXIST WITH A MYELOMENINGOCELE

Hydrocephalus and myelomeningocele are two conditions that are often seen together, especially in infants. Hydrocephalus is a condition characterized by an abnormal accumulation of cerebrospinal fluid within the brain’s cavities, leading to increased pressure inside the skull. On the other hand, myelomeningocele is a type of spina bifida where the spinal canal and backbone do not close before birth, resulting in a sac-like protrusion of the spinal cord and its covering membranes through an opening in the spine.

The Relationship Between Hydrocephalus and Myelomeningocele

The coexistence of hydrocephalus with myelomeningocele can be attributed to several factors:

1. Obstruction of Cerebrospinal Fluid (CSF) Flow: In cases of myelomeningocele, there can be disruptions in the normal flow of cerebrospinal fluid due to the spinal defect. This disruption can lead to a blockage or obstruction in the circulation of CSF, causing hydrocephalus to develop.
2. Arnold-Chiari Malformation: Myelomeningocele is often associated with Arnold-Chiari malformation, where the lower part of the brain (cerebellum) extends into the spinal canal. This malformation can cause hindrance to the normal flow and absorption of CSF, contributing to hydrocephalus.
3. Impaired CSF Absorption: The presence of myelomeningocele can also affect the absorption of cerebrospinal fluid within the brain. The leakage of CSF through the spinal defect can disrupt the balance between production and absorption, leading to hydrocephalus.
4. Increased Intracranial Pressure: The combination of myelomeningocele and hydrocephalus can result in increased intracranial pressure within the skull. This elevated pressure can further exacerbate the symptoms associated with both conditions.
5. Surgical Interventions: In many cases, surgical interventions for myelomeningocele may inadvertently lead to complications such as hydrocephalus. For example, if there is manipulation or damage to structures involved in CSF circulation during surgery, it can predispose the individual to developing hydrocephalus.

Conclusion

In conclusion, the close association between hydrocephalus and myelomeningocele can be explained by factors such as obstruction of CSF flow, Arnold-Chiari malformation, impaired CSF absorption, increased intracranial pressure, and surgical interventions. Understanding these interrelated mechanisms is crucial for effective management and treatment of individuals presenting with both conditions simultaneously.