A problem often mischaracterized or “Why Grandfather/ Grandmother might need a spinal tap”
I want to highlight a problem that is very often overlooked or misinterpreted.
When a person over 60 years old begins to forget things and gets dulled intellectually there is an increasing frequency that they are given the diagnosis of “probable early Alzheimer’s disease”.
Interestingly, they are now often started on an assortment of quite expensive medications or a “study protocol” by the neurologist. Usually there is no improvement in function with the medications but the family is shamed into continuing them to the benefit of the pharmaceutical industry. Such medications may even make matters worse by adding undesirable side effects.
I am dismayed that often those newly diagnosed as demented are not even given proper testing before this diagnosis and treatment are given. Most often there has been a cursory history and exam, which surprisingly often includes electro diagnostic testing such as, nerve conductions, EEG and evoked potential studies (none of which is definitive or actually helpful to diagnose dementia but are good income for the neurologist(s) involved).
I am still surprised that the diagnosis of Alzheimer’s disease is often reached without having done any imaging of the brain whatsoever.
It is very important that a proper history, physical exam and testing be done because there is no cure for Alzheimer’s dementia but there are many other conditions which can be improved or cured by early, proper intervention.
Remember that many correctable medical conditions can cause reduced mental function. A good example is severe thyroid disease may cause significant cognitive impairment and can be likewise significantly improved by corrective treatment. Be sure thyroid testing is done as part of a thorough medical evaluation.
What is Hydrocephalus anyway? Our brains make the spinal fluid and normally it flows from a cavern (ventricle) in the center of each side of our brain to the base of our brain where the two channels combine. Then the spinal fluid flows out of our head into the neck and down the spinal canal where it is absorbed. The production and absorption of spinal fluid should be in balance.
There are two age groups that have the most hydrocephalus, infants and people over 60 years old. It is possible but very uncommon in the people of in-between ages.
Hydrocephalus (water on the brain) is the reason that the pediatrician measures around the baby’s head. In infants the bones of the skull are soft and not yet stuck together along the edges so if there is poor drainage of the brain fluid, the head gets bigger as the fluid accumulates. Placement of a drain in the ventricles of the brain to bring the excess fluid under the skin down the neck to the abdominal cavity can save the infant from brain damage and intellectual retardation. Hydrocephalus is then mostly forgotten about past the infant stage.
Once the skull is hardened and fused into a solid shell to protect the brain, excess water in the brain cannot be determined by measuring the outside of the head since it will not increase in size. If there is too much water in the brain of an adult, brain damage can result.
The second peak occurrence of hydrocephalus is in adults over 50, increasing by each further decade of age. The triad of symptoms for adult hydrocephalus consists of: cognitive changes; bladder incontinence’ and impaired gait.
Cognitive changes such as poor memory, somnolence, irritability, wandering, reduced hygiene, apathy or blunted affect may be seen with adult hydrocephalus.
Bladder incontinence is a classic symptom of hydrocephalus.
Gait disturbances in hydrocephalus may look like alcohol abuse. Frequent falling, difficulty getting up from sitting and generalized clumsiness are common with adult hydrocephalus.
It is important that a brain scan be performed to see if the internal spaces (ventricles) of the brain are enlarged (ventriculomegaly).
However, there are some variations of hydrocephalus, which may not make the ventricles look significantly enlarged! That is why it is very important to move to the next step in diagnosis and have a large volume spinal tap done. Under fluoroscopy, a needle is inserted into the spinal canal and 40 to 60 cc of spinal fluid is taken out. If the person has hydrocephalus, there usually is a significant improvement in alertness and generalized function! This improvement in function may last for a few hours up to a few weeks in duration. Once the diagnosis of hydrocephalus is confirmed the affected adult can have a Ventricular peritoneal shunt placed by the neurosurgeon.
Placing a VP shunt for hydrocephalus is one of the most successful surgeries that neurosurgeons perform. When hydrocephalus is the problem, a shunting can bring back the parent from the progressive brain fog to improved functioning. It is often a remarkable improvement in function, which improves life for the patient and the family who care about them.
The failure to properly diagnose adult hydrocephalus is a tragedy that can be averted.
A large volume spinal tap followed by careful observation for the effects is the most physiologic and reliable testing for hydrocephalus in adults.
Be Well and be sure to think about water on the brain when grandparents are showing the triple symptoms of mental status changes, impaired bladder control and impaired gait.
Sam Wise MD