Aqueductal stenosis is a narrowing of one of the channels in the brain that acts as a conduit for cerebrospinal fluid, the fluid that bathes the brain and provides protective properties. In a person with aqueductal stenosis, the free flow of fluid is restricted and the patient may develop hydrocephalus, a buildup of cerebrospinal fluid that leads to neurological complications over time. One of the most common causes of congenital hydrocephalus, where someone is born with fluid in the brain, is aqueductal stenosis.
This condition involves the cerebral aqueduct, also known as the aqueduct of Sylvius. This particular channel for cerebrospinal fluid runs between the third and fourth ventricles. When the aqueduct narrows, it limits the flow of cerebrospinal fluid, and the fluid can begin to back up and build up. Over time, this can cause inflammation that will lead to brain damage by putting pressure on brain cells. In infants, it can cause distortions in the shape of the skull because the developing skull expands to accommodate excess fluid.
In congenital aqueduct stenosis, something goes wrong during brain development and this canal is narrow or not fully formed, which affects the circulation of cerebrospinal fluid in the fetus. In acquired cases, someone develops a condition such as an infection, inflammation, or neurological disease that damages the aqueduct and causes it to narrow. This leads to obstructive hydrocephalus, where cerebrospinal fluid builds up because it has nowhere to go.
People with aqueductal stenosis generally experience headaches that may get worse over time and do not resolve with rest or medication. Nausea and vomiting can also develop as a result of pressure on the brain. Altered level of consciousness is another symptom that tends to occur as hydrocephalus persists without treatment. In general, any time people experience a combination of headaches, mood swings, and nausea, it can be a warning sign that there is a neurological problem.
Medical imaging studies of the brain will be used to determine what is happening inside and to determine how much damage has occurred, if any. The recommended treatment is usually the installation of a shunt to allow excess cerebrospinal fluid to drain safely. If it is a tumor, surgery is recommended to remove the tumor and removal of the growth should resolve the hydrocephalus. Other treatment options may include radiation therapy to tumors that are considered inoperable. These treatments are performed by a neurosurgeon, a doctor who specializes in performing surgery on the brain.