In this study, the US researchers investigated the spontaneous spinal cerebrospinal fluid-venous fistula as a cause of behavioral variant of fronto-temporal brain sagging syndrome.
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. The behavioral variant of fronto-temporal 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.
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 imaging of the spine.
The diagnosis of cerebrospinal fluid venous fistulas is important because these patients do not respond well to epidural blood patches and usually require surgery to cure.
About the study
In this study, 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).
The results showed, for the first time, that spinal cerebrospinal fluid leaks are responsible for a significant proportion of cases with behavioral variant of fronto-temporal brain sagging syndrome. Nine patients (43%) had a cerebrospinal fluid-venous fistula.
The identification of a cerebrospinal fluid-venous fistula is important because it allows effective treatments, such as surgical ligation of the fistula. All nine patients from this study with cerebrospinal fluid-venous fistula underwent surgical ligation of the fistula. In all nine patients, complete or nearly complete and sustained resolution of cerebrospinal fluid leak symptoms was obtained, accompanied by a reversal of the brain sagging.
The authors concluded that the detection of spontaneous spinal cerebrospinal fluid-venous fistula as a cause of behavioral variant of fronto-temporal brain sagging syndrome, requires specialized imaging that is invasive and not widely available. Even with this specialized imaging the source of the spinal cerebrospinal fluid loss remains elusive in more than half of patients. However, continuing to detect cerebrospinal fluid-venous fistulas is worthwhile because treatment of the fistula is effective and associated with low risk.
This article is published in the scientific journal Alzheimer’s Dementia. Schievink WI, Maya M, Barnard Z, et al. The reversible impairment of behavioral variant frontotemporal brain sagging syndrome: Challenges and opportunities. Alzheimer’s Dement. 2022; 8: e12367. https://doi.org/10.1002/trc2.12367