Watch Dr. Mark Souweidane explain the origins and treatment of hydrocephalus, including the traditional shunt surgery and the newer, minimally invasive procedure called endoscopic third ventriculostomy.
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The two main types of hydrocephalus are congenital (developed before birth) and acquired (developed during or after birth). Hydrocephalus is further classified as "communicating" and "non-communicating," each of which occurs in a different area of the brain. In non-communicating (also called obstructive) hydrocephalus, there is a blockage of CSF flow from the ventricles to the surfaces of the brain and spinal cord. Communicating hydrocephalus results from impaired reabsorption of CSF into the circulatory system.
Another type of hydrocephalus is termed "normal pressure" hydrocephalus. This condition, which normally affects older people, enlarges chambers in the brain (ventricles) without increasing pressure in the brain.
Hydrocephalus can result from a wide range of causes, including congenital malformations that do not allow CSF to flow properly, tumors or blood clots that obstruct CSF circulation, or as a complication of injury or infection.
Symptoms of hydrocephalus will differ depending on the patient's age. In infants, symptoms include irritability, poor head control, poor feeding, and a bulging "soft spot" at the top of the head. Because the bones of the infant skull are growing and can expand to accommodate increased amounts of CSF, those with hydrocephalus typically have an increase in the circumference of the head. Older children and adults with hydrocephalus can experience headache; vomiting; nausea; problems with vision, balance, and walking; and a downward gaze, called "sunsetting of the eyes." Symptoms of normal pressure hydrocephalus include problems walking, urinary continence, and dementia.
Hydrocephalus may be diagnosed before birth by ultrasound. Fetal and neonatal ultrasound may also be used for very young children to monitor the ventricles of the brain and watch for intraventricular bleeding. The growth of a baby's head may also be tracked if it is larger than normal. The blockages and structural problems that lead to hydrocephalus the can be examined with computed tomography (CT) and magnetic resonance imaging (MRI) scans.
Once the cause of hydrocephalus has been identified, a physician can determine whether the head will eventually grow enough to accommodate the imbalance of CSF on its own or whether surgical intervention is needed.
- Surgery often involves the placement of a shunt, an implanted tube that allows excess fluid to drain to other parts of the brain or elsewhere in the body for reabsorption. A ventriculoperitoneal shunt diverts excess CSF from the brain to the abdominal cavity.
- Alternatively, surgeons may perform endoscopic third ventriculostomy. In this minimally invasive surgery, tiny instruments and a tiny camera called an endoscope are manipulated through tubes inserted in a small incision. The endoscope is navigated to the third ventricle of the brain, where a tiny incision allows built-up CSF to leave the ventricles and occupy its normal position surrounding the brain.
- If the blockage is caused by a tumor, surgical tumor resection is used both to remove the tumor and to restore the normal flow of CSF. In appropriate cases, the surgeon may use an endoscopic approach to remove the tumor. This approach is less invasive than open surgery and can reach tumors that are not readily accessible by conventional means.