- Leakage of the fluid that protects and supports the brain can cause ‘brain sagging’, which is associated with the same behavioral symptoms of dementia, which is less common.
- New research suggests that surgically correcting such leaks can reverse symptoms.
- However, the research also found that it was not always possible to identify the source of the leak.
- In these cases, alternative treatments for brain sagging often do not improve the symptoms of dementia.
When neurons in the frontal and temporal lobes of the brain are damaged, frontotemporal dementia or
FTD is relatively rare in older adults compared to other types of dementia, but is the most common cause of the condition in people up to age 60.
A subset of patients has behavioral FTD or bvFTD with progressive changes in behavior, personality, and thinking skills.
For example, people with bvFTD are often unable to empathize with others, which can lead to loss of previous inhibitions and inappropriate behavior.
Memory impairment, which is usually a hallmark of dementia, occurs only in the later stages of bvFTD.
A new study by researchers at Cedars-Sinai Medical Center in Los Angeles, California, adds evidence that cerebrospinal fluid leaks can cause symptoms of bvFTD.
The good news from this study is that specialized imaging techniques can often identify the cause of the leak, allowing the surgeon to correct it and completely cure the patient.
“Many of these patients have cognitive, behavioral and personality changes so severe that they are either arrested or placed in a nursing home,” said Cedars-Sinai’s Cerebrospinal Fluid Leakage and Microvascular Neurosurgery Program. Director and Professor of Neurosurgery Wouter Schievink, Ph.D. .
“If you have behaviorally variable frontotemporal dementia of unknown cause, there is no treatment available,” said Dr. Schievink, who led the study.
“But our research shows that patients with cerebrospinal fluid leaks can be cured if the cause of the leak can be found,” he added.
Cerebrospinal fluid (CSF) normally provides buoyancy to the brain and acts as a shock absorber. When fluid leaks, the pressure in the skull drops, causing the brain to droop and impede its function.
Clear signs of a cerebrospinal fluid leak include severe headaches that improve when the person lies down and excessive daytime sleepiness, even after a good night’s sleep.
Magnetic resonance imaging (MRI) brain scans can reveal sagging in the brain, Dr. Schievink says, which doctors often refer to as a condition known as Chiari malformation, in which brain tissue protrudes into the spinal canal. I make a mistake.
Even if a neurologist can pinpoint sagging in the brain, it can be difficult to pinpoint the cause of the CSF leak.
An imaging technique called a CT myelogram can identify tears or cysts in the membrane surrounding the CSF.
However, Schievink and his colleagues recently discovered that CSF can leak from the spine into the veins through holes or ‘fistulas’. This is barely visible on her routine 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, CSF is injected with a fluorescent substance and its movement is tracked.
In a new study, researchers used DSM to image the spinal cord in 21 patients with bvFTD due to brain sagging.
They found CSF venous fistulas in 9 (42.8%) patients. Surgery to close the fistula reversed brain sagging and dementia symptoms in all nine subjects.
They treated the remaining 12 patients whose leaks could not be identified with treatments designed to reduce slack in the brain, such as injecting CSF into the spine. However, only three of these patients improved with this treatment.
“Major efforts are needed to improve the detection rate of CSF leakage in these patients,” said Dr. Schievink.
“We have developed non-targeted treatments for patients with undetectable leaks, but as our study shows, these treatments are far less effective than targeted surgical correction of leaks. ‘ he adds.
The author concludes:
“[P]It is worth pursuing the detection of cerebrospinal fluid venous fistulas. fistula treatment because it is effective and associated with low risk. On the other hand, no disease-modifying treatments are available for the devastating symptoms of bvFTD. ”
Dr. Per Kristian Eide, senior consultant neurosurgeon at Oslo University Hospital, Riksspitalet, Norway, recently co-authored a review on the diagnosis and treatment of ‘braindrop dementia’.
Dr. Eide said MNT The availability of the DSM that researchers in the new study used to find CSF leaks was not a major obstacle to successful diagnosis of the condition.
“Since imaging techniques are so widespread and available, misdiagnosis is largely due to physicians’ lack of awareness,” said Dr. Eide, who was not involved in the study.
“[C]Clinicians need to be aware of this disease, as symptoms may be reversed with correct treatment.
The authors of the new study emphasize that the target population is a select group of patients referred to specialized treatment centers.
They wrote that their findings may not be broadly applicable to other patients with this type of dementia.
Furthermore, the total number of patients in the study was relatively small.