Hydrocephalus
Einstein Health Glossary
ICD 10 - G91
Progressive memory impairment, walking instability, and difficulty retaining urine. Sometimes considered “normal” issues in the elderly, these symptoms should be seen as warning signs to seek medical help: the presence of all three symptoms together may indicate hydrocephalus, a highly limiting condition caused by an increase in cerebrospinal fluid (CSF) in the brain cavities known as ventricles.
In Brazil, there are approximately 11,000 new adult cases per year, affecting men and women equally, especially from the age of 65. However, considering that the disease is underdiagnosed, the actual number is likely higher.
Hydrocephalus occurs when CSF, which circulates through the brain acting as a protective system, cannot be reabsorbed. Normally, about 250 ml of this fluid circulates and is reabsorbed by the adult brain, a volume that is renewed on average three times a day. Unlike infant hydrocephalus, where the head expands due to the lack of skull bone consolidation, in adults the unabsorbed CSF accumulates in the ventricles, compressing important brain structures and causing the three symptoms.
Hydrocephalus can result from excessive CSF production, caused by factors such as head trauma, stroke, brain tumors, previous brain surgeries, and meningeal hemorrhage. It can also be caused by blockage of the aqueducts (channels through which CSF flows), either due to congenital defects or tumors — these are rarer cases and can affect people of all ages.
The vast majority of hydrocephalus cases in elderly adults, however, are associated with the brain’s inability to properly reabsorb CSF for reasons still unknown. This is called Idiopathic Normal Pressure Hydrocephalus (iNPH), because despite the enlargement of the ventricles, the CSF pressure remains normal.
Hydrocephalus of unknown cause is also the most complex to diagnose, as the characteristic symptom triad (memory and/or cognitive impairment, gait disturbance, and urinary incontinence) is also present in other conditions affecting the elderly. “More than 90% of patients who present the symptom triad have hydrocephalus,” says Dr. Reynaldo André Brandt, neurosurgeon at Einstein and chairman of the board of the Sociedade Beneficente Israelita Brasileira Albert Einstein.
“It is an extremely limiting disease. The patient becomes unable to walk and is confined to bed, with incontinence that leads to recurrent urinary infections,” notes Dr. Ivan Hideyo Okamoto, neurologist at Einstein.
Diagnosis
The diagnosis of hydrocephalus is made through clinical history and imaging tests that show enlarged ventricles. When Idiopathic Normal Pressure Hydrocephalus (iNPH) is suspected, a therapeutic test called the Tap Test is performed. Initially, the patient undergoes cognitive memory evaluation and gait testing. On the following day, a lumbar puncture (spinal tap) is performed to remove about 30 ml of cerebrospinal fluid (CSF), which temporarily reduces retention in the ventricles.
The tests are repeated after the puncturetap procedure. If the patient shows improvement in the previously impaired functions, iNPH is confirmed. “The Tap Test is important for diagnostic confirmation, as it increases the safety of recommending a surgical procedure for older patients,” explains Dr. Okamoto.
Einstein was the pioneering institution in applying the Tap Test in a systematic way and without the need for hospitalization. The patient undergoes neuropsychological evaluation and gait testing, and returns the next day for the CSF puncturetap. A few minutes later, the patient is re-evaluated to check whether the response to the puncture was positive. “Re-evaluating immediately after the puncture significantly improves the accuracy of the test, since the CSF can begin to accumulate again in the ventricles within about two hours,” highlights Dr. Brandt.
Effective and Safe Surgery
Ventriculoperitoneal shunt (VPS) surgery is the preferred treatment for hydrocephalus. This procedure has been used for many decades and has success and safety rates above 80%. It involves placing a catheter in the brain’s ventricle, connected to a valve and another catheter that runs from the neck to the peritoneal cavity in the abdominal region.
The valve regulates the flow, opening whenever the ventricles enlarge and draining the excess cerebrospinal fluid (CSF), which is carried through the catheter to the peritoneal cavity. Symptoms usually disappear completely shortly after the procedure, and recurrence rates are extremely low.
Technological advances have led to the development of adjustable valves that can be regulated without invasive procedures if needed. Previously, any valve malfunction required replacement through another surgery.
The frequent confusion of hydrocephalus symptoms with those of conditions like Alzheimer’s often delays or even prevents diagnosis. However, with early diagnosis and proper treatment, hydrocephalus can be completely cured, restoring the patient’s and their family’s quality of life.