Hydrocephalus is the growth and enlargement of the chambers or ventricles in the brain tissue, which have cerebrospinal fluid, as a result of an increase of this fluid. In normal healthy individuals, the cerebrospinal fluid is produced by specialized cells in these chambers and is reabsorbed after flowing around the spinal cord, the brain chambers, and the cortex. As a result of the increase of building-up of this fluid, reduction of its absorption, or there is a blockage in the paths on the place of production or to the site of absorption, fluid accumulation may increase in the ventricles of the brain and hydrocephalus may develop.
Hydrocephalus may be seen at any age. Hydrocephalus seen in adults has slightly different characteristics compared to childhood hydrocephalus. Hydrocephalus occurring in adulthood can usually develop after tumors and/or brain hemorrhages and traumas. Another specific type of hydrocephalus is normal pressure hydrocephalus which is also seen in adults (also known as Hakeem-Adams syndrome).
Hydrocephalus after tumor: This situation can be seen in tumors that compress the liquid flow spaces, especially those that compress or settle into the liquid cavities of the cerebrospinal fluid. In these cases, removal of the tumor is an effective method in the treatment of hydrocephalus because it will open the liquid flow pathways. However, the content of certain specific tumors, such as vestibular schwannoma and epidermoid tumor, can cause hydrocephalus. In these cases, the hydrocephalus may not recover even if the tumor is surgically removed. In this case, the treatment of hydrocephalus may also be necessary.
Hydrocephalus after bleeding: After the cerebrospinal fluid is released from the ventricles in the brain, it circulates around the brain and around the spinal cord and is absorbed from the small canaliculus. The cerebrospinal fluid is located between the brain and the arachnoid membrane, which is one of the membranes covering the brain. No matter where it comes from the brain, bleedings that occur into cerebrospinal fluid almost always get mixed to the chamber where this fluid is located and to the whole fluid where it circulates in the ducts. After these bleedings that called subarachnoid hemorrhage (SAH), hydrocephalus develops because blood and blood products block the spillway of fluid by obstructing the flow of liquid flow or by blocking small ducts that provide fluid absorption. The rate of hydrocephalus development is higher if this hemorrhage is related to a vein bubble (aneurysm). Rarely in middle-aged and elderly patients, hemorrhage into the brain tissue (parenchymal) due to blood pressure may also be caused by opening to subarachnoid space or ventricle, resulting in hydrocephalus.
Normal pressure hydrocephalus (Hakeem Adams syndrome): Although this type of hydrocephalus occurs usually in elderly patients, it as also can occur sometimes in middle-aged and young patients. Characteristic symptoms of this disease include gait disorder (walking in short steps, impaired balance), forgetfulness (especially in recent history), and urinary incontinence. The symptoms of this disease can often be confused with dementia. Brain magnetic resonance images of patients presenting with this type of symptoms are recommended to perform a lumbar puncture (waist fluid removal) to clarify the diagnosis in patients with normal pressure hydrocephalus. Patients whose complaints regress after lumbar puncture, diagnosis becomes clear and shunt surgery may be recommended to these patients.
Symptoms of hydrocephalus in adult patients
In middle-aged adults, balance disorder, urinary incontinence, dementia may be seen as well as headache, difficulty in waking up or staying awake, personality disorder, and visual impairment. Elderly patients may experience instability in walking, difficulty in remembering, urinary incontinence, as well as impaired communication and headache.
- Magnetic Resonance Imaging (MRI) is the gold standard. With these examinations, the brain’s own tissue can be evaluated in detail. In addition, the movement of cerebrospinal fluid in the brain tissue between cells and the flow and movements of this fluid in and around the brain’s ventricle and duct can be evaluated. In addition, pathologies such as tumor causing hydrocephalus can also be detected.
- Magnetic resonance imaging (MRI) methods that show cerebrospinal fluid flow: These examinations are especially used in cases that prevent the flow of cerebrospinal fluid. Although large tumors and other large-scale pathologies that block the fluid flow can be diagnosed by normal MRI, small-sized tumors and sometimes narrowness and atresia which are congenital or acquired and in the way of fluid flow may not be seen in normal MRI. MRI examinations showing cerebrospinal fluid flow may also be used in these cases.
- Computed tomography (CT) is also frequently used in hydrocephalus, although it is better to detect bone tissue. It also shows bleeding in patients, especially the bleeding which occurred recently.
- Placing a shunt: The purpose of shunt insertion is to transfer the accumulated excess fluid in the brain cavities into different spaces of the body. In this process, a catheter is inserted into the ventricles in the head, this catheter is connected with the pump, a second longer catheter is connected to the other end of the pump, this catheter is carried under the skin into the abdominal cavity and its tip is placed inside the abdomen. In this way, the excess fluid in the brain is transferred into the abdomen. Excess fluid is absorbed from the abdomen. Combining the catheters leading to the brain and abdomen just above the skull, the pump allows the cerebrospinal fluid to flow controlledly over a certain pressure. In this way, the fluid accumulated in the brain is discharged to another part of the body. The abdominal cavity is often used to drain this fluid. The other end of the catheter that goes to the abdomen can also be connected to different parts of the body. In some cases, this fluid may be evacuated to the chest cavity or to the heart with the help of a vena which goes from neck to the heart. The shunt pumps that are used can be of constant pressure setting and can be changed from outside after adjustment. The choice is made according to the clinical status of the patients. Patients with a shunt are closely monitored. Failure in shunt or infection may be seen. Infection usually occurs in the first 6 weeks after surgery, but also may be seen later. Shunts with antibiotics may be used in patients with a recurrent shunt infection.
Endoscopic third ventriculostomy: This treatment option can be applied in the time of mechanical obstruction of the ways that provide the fluid transfer. Each patient with hydrocephalus may not be suitable for this treatment. In this treatment option, to ensure fluid flow in the ventricles (fluid-filled spaces of the brain), a new hole is opened by the endoscope by entering to these spaces and the flow of accumulated fluid is ensured.