Adult Onset Hydrocephalus

What is Adult Onset Hydrocephalus?

Hydrocephalus is a condition in which excess cerebrospinal fluid (CSF) builds up within the ventricles (fluid-containing cavities) of the brain. It is often described as “water on the brain,” the “water” being CSF, a clear fluid surrounding the brain and spinal cord. CSF is produced and stored in the ventricles and typically flows around the brain and spine, moving ventricle to ventricle. It acts as a cushion or shock absorber for the brain and spine. CSF flows between the cranium and spine to regulate changes in pressure within the brain, and works as a vehicle for delivering nutrients to the brain and eliminating waste. In a healthy body, excess fluid will drain away and be reabsorbed by the surrounding tissues. When the CSF builds up, the ventricles enlarge due to the extra fluid, then press on the surrounding tissue of the brain, causing particular sets of symptoms.

Hydrocephalus may be congenital or it may be acquired, wherein some sort of obstruction occurs in the CSF dynamics in later years. One of the variations of Dr. Berti treats is Normal Pressure Hydrocephalus (NPH), also known as Hakim/Adams Syndrome. This type of hydrocephalus usually occurs in older adults. NPH differs from other types of hydrocphalus in that the CSF drainage is blocked slowly over time. The gradual dilation of the ventricles means that the fluid pressure in the brain may not be as high as in other types of hydrocphalus, but the ventricles still press on the brain and cause symptoms. The “normal” in NPH simply refers to the relatively low pressure for hydrocephalus.

There are many causes for hydrocephalus in adulthood. Briefly, they may include obstructive tumors, post-meningitic hydrocephalus, post-hemorrhagic hydrocephalus with a subarachnoid bleed, or post-traumatic hydrocephalus, with a bleed as well in the subarachnoid space. You may have hydrocephalic conditions with meningeal carcinomatosis (metastasis), or other primary tumors such as medulloblastomas, primitive neuroectodermal tumors, ependymomas, and more, that can travel along the subarachnoidspace and obstruct the absorption of the CSF. In extreme cases in developing countries, a person may contract parasites that invade the subarachnoid space and produce pachymeningitis, such as cysticercosis, mycosis, and others.

What are the symptoms of Adult-Onset Hydrocephalus?

Those with adult-onset hydrocephalus may complain of headaches, nausea, difficulty focusing the eyes, and an unsteady walk.  Leg weakness, sudden falls, irritability, drowsiness, personality changes, and seizures are also possible symptoms. Normal Pressure Hydrocephalus is characterized by the Hakimov triad: dementia, urinary incontinence, and gait apraxia, or abnormal gait. Abnormal gait is often the earliest symptom noted and is generally considered to be the symptom that sees the most improvement. Gait apraxia is characterized by the motor inability to move in the presense of full muscle strength and movement. The gait is distinctively broad-based, shuffling, and slow, and some patients report feeling like their feet are glued to the ground. The severity of gait apraxia ranges from mild (just shuffling) to severe (the patient being unable to move or stand at all). This is due to the dilation of the frontal horns of the lateral ventricles and the stretching of the fibers that generate in the frontal lobe.

If normal pressure hydrocephalus is left untreated, the symptoms may worsen over time. For example, patients with advanced NPH may experience seizures. Dementia and/or bladder control problems usually appear after gait disturbances, as the condition progresses. Mild dementia can be described as a loss of interest in daily activities, forgetfulness, difficulty dealing with routine tasks and short-term memory loss, but not everyone with NPH develops an obvious mental impairment. Bladder control problems usually involve urinary frequency and urgency in mild cases, and in severe cases, however, a complete loss of bladder control (urinary incontinence) may result.

How is Hydrocephalus Diagnosed?

A physician should select the appropriate diagnostic tool based on a person’s age, clinical presentation, and history. Because multiple other illnesses (including Parkinsons Disease, Aphasia, and frontal lobe symptoms, to name a few) may present similarly to NPH, it is important for your physician to perform a thorough and detailed history and physical examination. Physicians consider the Hakimov triad of symptoms when diagnosing Normal Pressure Hydrocephalus: gait apraxia, dementia, and incontinence. As mentioned above, one of the first warning signs of hydrocephalus is a distinctive gait, where a person may have trouble picking up his or her feet. If the person has hydrocephalus, an examination of  gait changes will reveal changes in walking related to pressure placed on parts of the brain. Deep tendon reflexes may be increased in the lower legs. Laboratory tests are generally unhelpful, but imaging is a valuable tool for diagnosis. In most cases, your physician will initially run a brain CT scan, or use ultrasounds or an MRI of the brain in order diagnose hydrocephalus accurately. Additionally, patients with suspected NPH may undergo diagnostic CSF removal (either large volume lumbar puncture and/or external lumbar drainage), which has both diagnostic and prognostic value

How is Hydrocephalus Treated?

Hydrocephalus may be treated directly, by removing the cause of CSF obstruction, or indirectly, by diverting the fluid away from the brain and spine to another body cavity (typically the peritoneal cavity) where it can be reabsorbed by the body via a ventriculoperitoneal shunt system. A shunt system consists of the shunt, a catheter, and a valve. One end of the catheter is placed within a ventricle inside the brain, or in the CSF outside the spinal cord. The other end is usually placed within the peritoneal cavity, or wherever the physician decides to place it for CSF reabsorption. A shunt is a flexible and sturdy plastic tube.The valve is located along the catheter and should regulate and maintain a one-way CSF flow.

A limited number of individuals can be treated with an alternative procedure called third ventriculostomy. In this procedure, a neuroendoscope — a small camera that uses fiber optic technology to visualize small and difficult to reach surgical areas — allows a doctor to view the ventricular surface. Once the scope is guided into position, a small tool makes a tiny hole in the floor of the third ventricle, which allows the CSF to bypass the obstruction and flow toward the site of resorption around the surface of the brain.

Recovery:

Dr. Berti will evaluate your neurological functions after your surgery. Please contact him if you experience redness, tenderness, or pain along the length of the tube or incision, drowsiness, fever, nasuea, headache, or vomiting, abdominal pain, or the return of pre-operative symptoms. He is an enthusiastic proponent of rehabilitation, and will recommend a course of post-operative treatment based on whether your neurological symptoms persist. Keep in mind that your recovery may be limited by various factors, such as the existing damage from hydrocephalus prior to being diagnosed and your body’s ability to heal. Long-term follow-up by Dr. Berti is required as hydrocephalus is an ongoing condition. You will potentially need imaging to be performed continually to determine whether the shunt system is working properly.

Sources:
Dr. Aldo Berti, M.D., F.A.C.S.

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001759

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0003902

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1705504/

http://www.ninds.nih.gov/disorders/hydrocephalus/detail_hydrocephalus.htm