The behavioral variant of frontotemporal dementia is an early-onset dementia, clinically characterized by progressive changes in social behavior, personality, and cognition. This disease is devastating to patients and their families, and there is no cure. In this study, the American researchers investigated the spontaneous spinal cerebrospinal fluid-venous fistula as a cause of a behavioral variant of frontotemporal dementia due to severe brain sagging.
Spontaneous spinal cerebrospinal fluid leak and associated loss of cerebral buoyancy cause orthostatic headaches. However, spontaneous spinal cerebrospinal fluid-venous fistula can also cause symptoms indistinguishable from the behavioral variant of frontotemporal dementia due to severe brain sagging, as visualized on brain magnetic resonance imaging.
Current technology has significantly increased the detecting efficiency of cerebrospinal fluid leaks, particularly the cerebrospinal fluid-venous fistula. Detection of cerebrospinal fluid-venous fistulas requires specialized spinal imaging techniques, such as digital subtraction myelography or dynamic computerized tomography myelography because this type of cerebrospinal fluid leak cannot be detected by conventional spine imaging.
The identification of a cerebrospinal fluid-venous fistula is essential because these patients do not respond well to epidural blood patches, and usually require surgical ligation of the fistula.
About the study
The researchers performed digital subtraction myelography in the lateral decubitus position under general anesthesia in 21 consecutive patients with frontotemporal dementia brain sagging syndrome (mean age 56.2 years).
Nine patients (43%) had a cerebrospinal fluid-venous fistula. All of them underwent surgical ligation of the fistula, which resulted in complete or nearly complete and sustained resolution of cerebrospinal fluid leak symptoms, and a reversal of the brain sagging.
The authors noted that their results revealed, for the first time, that spinal cerebrospinal fluid leaks are responsible for a substantial proportion of individuals suffering from a behavioral variant of frontotemporal brain sagging syndrome.
Conclusion
Researchers concluded that the detection of spontaneous spinal cerebrospinal fluid-venous fistula requires specialized imaging that is invasive and not widely accessible. Despite the use of this specialized imaging technique, the source of spinal cerebrospinal fluid loss remains elusive in more than half of patients. Therefore, researchers suggested that it is important to continue to detect cerebrospinal fluid-venous fistulas because their treatment is effective and associated with low risk.
This article is published in Alzheimer’s Dementia.
Journal Reference
Schievink WI, Maya M, Barnard Z, et al. The reversible impairment of behavioral variant frontotemporal brain sagging syndrome: Challenges and opportunities. Alzheimer’s Dementia 2022; 8: e12367. https://doi.org/10.1002/trc2.12367
