Behavioral variant frontotemporal dementia (bvFTD) is a type of dementia – one of the most common in people under 60 years of age – that currently has no cure, and as the disease progresses, those affected experience cognitive, personality and behavioral alterations that prevent them from leading a normal life. Now, however, Cedars Sinai researchers have uncovered a previously unknown possible cause of this dementia: a cerebrospinal fluid leak that could be treated if its source is detected, offering great hope to some of these patients. Their findings have been published in Alzheimer’s & Dementia: Translational Research and Clinical Interventions.
“If they have a behavioral variant of frontotemporal dementia with an unknown cause, then there is currently no treatment available. But our study shows that patients with cerebrospinal fluid leaks can be cured if we can find the source of the leak,” explained Wouter Schievink, MD, director of the Cerebrospinal Fluid Leak and Microvascular Neurosurgery Program and professor of neurosurgery at Cedars-Cedars. Sinai.
Cerebrospinal fluid (CSF) circulates within the brain and spinal cord and protects these organs from injury, but when it leaks into the body, the brain can become weak and symptoms of dementia appear. Although brain flaccidness can be detected by an MRI, Schievink cautions that many patients go undiagnosed, so she advises doctors to recheck the MRI of those who show symptoms to “make sure there’s no evidence of brain flaccidity.” cerebral”.
When the CSF venous fistulas were surgically closed, the cerebral flaccidity and frontotemporal dementia symptoms of all nine patients completely disappeared.
Other symptoms that may alert you to this problem are severe headaches that are relieved when the patient lies down, excessive sleepiness even after a good night’s sleep, and a medical history such as whether the patient has ever been diagnosed with a brain malformation. Chiari, a condition in which brain tissue extends into the spinal column.
Detect the source of the cerebrospinal fluid leak
The problem is that even when brain flaccidity is detected, it can be difficult to identify the source of a CSF leak. If the fluid leaks through a tear or cyst in the surrounding membrane, it can be seen on CT myelography images using a contrast medium.
Schievink and his team discovered another cause of CSF leakage: venous CSF fistula. In these cases, the fluid leaks into a vein, making it difficult to pick up on a routine CT myelogram, and technicians have to use a specialized CT scan and watch the dye move as it flows through the vein. cerebrospinal fluid to detect these leaks.
The authors of the new study used this imaging technique in 21 patients with floppy brain and bvFTD symptoms, discovering CSF venous fistulas in nine of them. When the fistulas of these nine patients were surgically closed, it was found that the sagging brain and the symptoms of dementia completely disappeared.
In the case of the other 12 participants, it was not possible to identify the source of their leaks, so they were administered non-targeted therapies aimed at alleviating brain flaccidity, such as implantable systems to infuse CSF into the patient, but only three of them experienced a improvement of their symptoms.
“We have developed non-targeted treatments for patients in whom no leak can be detected, but as our study shows, these treatments are much less effective than targeted surgical correction of the leak,” said Schievink, who believes that “it is necessary to make great efforts to improve the detection rate of CSF leaks in these patients”.