Dementia can occur due to a variety of diseases or physical conditions, some more well-known and some less well-known. It is important to know these causes and understand their potential manifestations. One of these conditions is normal pressure hydrocephalus.
What is hydrocephalus?
Hydrocephalus (in Hebrew – hydroken) is a condition in which there is an accumulation of the fluid that protects the brain and spinal cord within cavities in the skull, called the ventricles of the brain. The spinal and cerebral fluid in each of us flows in a constant cycle, is constantly being produced anew within the ventricles of the brain and is absorbed into the bloodstream. A condition of hydrocephalus occurs when there is a violation of the delicate balance between the production of spinal and cerebral fluid and its absorption into the bloodstream.
The brain and spinal cord are contained within fixed, rigid bone structures of a fixed volume. When a change occurs in the delicate balance between the production and absorption of spinal and cerebral fluid, pressure is actually created within the skull (there is more fluid in the same unit of volume). When intracranial pressure is created, various physical symptoms will appear, such as headaches, double vision, seizures, excessive sleepiness, and more. At each stage of life, slightly different symptoms may appear that indicate a change in intracranial pressure.
What is the connection between hydrocephalus and dementia?
As mentioned above, increased intracranial pressure is usually accompanied by typical symptoms. However, there is also an exceptional situation : among the adult population (usually over the age of 60), there may be a condition of hydrocephalus that does not cause symptoms of increased intracranial pressure, and it is called " Normal Pressure Hydrocephalus" (NPH) . The causes of this type of hydrocephalus are unknown, and the symptoms are different from those of hydrocephalus at younger ages.
NPH is characterized by the appearance of symptoms of:
- Disturbance of stability
- impaired continence
- ירידה קוגניטיבית (mainly short-term memory)
Given the clinical course, which resembles other types of dementia, some patients are misdiagnosed. It is currently estimated that 1 in 10 people with dementia actually has NPH. Unlike other types of dementia, NPH is treatable. Early diagnosis and treatment of NPH is an important factor in the patient's rehabilitation. Successful treatment can allow a return to an active lifestyle.
What can be done for treatment?
Typically, a patient with suspected NPH will undergo MRI imaging to estimate ventricular size and clinical evaluation before and after lumbar puncture. This evaluation is intended to assess the potential effectiveness of installing a spinal and cerebrospinal fluid drainage system.
The treatment is the surgical installation of a drainage system. This system consists of a tube that drains some of the spinal and cerebral fluids from the brain cavities into another space in the body, usually into the abdominal cavity (which surrounds the abdominal organs, and not directly into the stomach or intestines), where the fluid is absorbed along with other fluids. If a drainage system is installed, in most cases, there is immediate improvement in all symptoms (motor skills, sphincter control, and cognition) and there is improvement over time, especially in terms of motor skills.
More information can be found at: hyd.org.il
Written by Noa Lubin – Chairwoman of the Israel Hydrocephalus Association