Fixing cerebrospinal fluid leaks may reverse symptoms
- Leakage of the fluid that protects and supports the brain can result in “brain sagging,” which is accompanied by the same behavioral symptoms as a less common form of dementia.
- A new study suggests that surgical repair of such leaks can reverse symptoms.
- However, the investigation also revealed that it is not always possible to identify the source of the leaks.
- In these cases, alternative treatments for cerebral slackening often fail to improve dementia symptoms.
Damage to neurons in the brain’s frontal and temporal lobes can lead to an early-onset dementia known as frontotemporal dementia or
FTD is relatively uncommon in older people compared to other types of dementia, but it is the most common cause of the condition in people up to the age of 60.
A subset of patients has behavioral FTD or bvFTD, which involves progressive changes in behavior, personality, and thinking skills.
For example, people with bvFTD often fail to empathize with others and may lose their previous inhibitions, which can lead to inappropriate behavior.
The memory problems that usually characterize dementia only appear later in the course of bvFTD.
A new study by researchers at Cedars Sinai Medical Center in Los Angeles, California, adds to the evidence that cerebrospinal fluid leakage can cause the symptoms of bvFTD.
The good news from the study is that a specialized imaging technique can often identify the source of the leaks, which surgeons can then repair, resulting in complete healing of the patient’s symptoms.
“Many of these patients experience cognitive, behavioral, and personality changes severe enough to result in arrest or being placed in nursing homes,” said Dr. Wouter Schievink, Director of the Cerebrospinal Fluid Leak and Microvascular Neurosurgery Program and Professor of Neurosurgery at Cedars-Sinai.
“If you have behaviorally variant frontotemporal dementia with an unknown cause, there is no treatment available,” said Dr. Schievink, who led the research.
“But our study shows that patients with CSF leaks can be cured if we can find the source of the leak,” he added.
Normally, the cerebrospinal fluid (CSF) gives the brain buoyancy and acts as a shock absorber. As the fluid leaks, the pressure inside the skull drops and the brain sags, disrupting its function.
Some telltale signs of a CSF leak are a severe headache that gets better when the patient lies down and significant daytime sleepiness, even after a good night’s sleep.
An MRI (magnetic resonance imaging) brain scan can show sagging of the brain, says Dr. Schievink, but doctors often confuse it with a condition known as Chiari brain malformation, in which brain tissue protrudes into the spinal canal.
Even if a neurologist correctly identifies brain sagging, it can be difficult to find the source of the CSF leak.
An imaging technique called a CT myelogram can locate a tear or cyst in the membrane that encloses CSF.
But Schievink and his colleagues recently discovered that CSF can also leak from the spine into a vein through a hole or “fistula,” which is almost invisible on a standard CT myelogram.
Detecting these leaks, known as CSF venous fistulas, requires a more specialized CT scan called a digital subtraction myelogram, or DSM. In this method, a fluorescent material is injected into the CSF and its movement is tracked.
For the new study, the researchers used DSM to image the spinal cords of 21 patients with bvFTD due to cerebral relaxation.
They discovered a CSF-venous fistula in nine (42.8%) patients. Surgery to close the fistula reversed the cerebral slack in all nine subjects and reversed their dementia symptoms.
They treated the remaining 12 patients whose leaks could not be located with therapies aimed at relieving brain sagging, such as: B. Infusions of CSF into the spine. However, the treatment relieved symptoms in only three of these patients.
“Great efforts must be made to improve the detection rate of CSF leaks in these patients,” says Dr. Schievink.
“We have not developed targeted treatments for patients who do not have a detectable leak, but as our study shows, these treatments are much less effective than targeted surgical repair of the leak,” he adds.
The study appears in
The authors conclude:
“[P]The detection of CSF-venous fistula is useful because treatment of the fistula is effective and low-risk, while there are no disease-modifying treatments for the devastating symptoms of bvFTD.”
dr Per Kristian Eide, Ph.D., Chief Neurosurgeon at Oslo University Hospital – Rikshospitalet, Norway, recently co-authored an overview of the diagnosis and treatment of brain sagging dementia.
dr told oaths MNT that the availability of DSM, which the researchers used to localize CSF leaks in the new study, was not the main obstacle to successfully diagnosing the condition.
“The imaging technique is widely used and available, so the level of misdiagnosis is primarily due to a lack of awareness among physicians,” said Dr. Eide, who was not involved in the study.
“[C]Doctors need to be aware of this disease as the symptoms can be reversible with the right treatment, while left untreated it can even be fatal,” he added.
The authors of the new study emphasize that their subjects were a highly selected group of patients who had been referred to a specialized treatment center.
They write that their findings may not be applicable to other patients with this type of dementia.
In addition, the total number of patients in the study was relatively small.
