The distinctive body habitus of frontotemporal dementia sagging brain syndrome

BACKGROUND: Frontotemporal dementia sagging-brain-syndrome (FTDSBS) is characterized radiographically by severe brain sagging. However, an underlying CSF leak can be found in only a minority of patients. Clinical observation suggests that some of these patients have a distinctive body habitus consisting of tall stature and obesity. The purpose of the present study was to evaluate FTDSBS patients for the presence of this particular body habitus. METHODS: This single center cross-sectional study included a consecutive group of FTDSBS patients, with or without an underlying spinal CSF-venous fistula. Comparison groups included patients with CSF-venous fistulas without FTDSBS and U.S. population reference estimates from NHANES. RESULTS: The mean age of the 43 men and five women with FTDSBS was 52.8 years. Patients with FTDSBS were taller and more obese than patients with CSF-venous fistulas without FTDSBS and the general population. The differences in height (5.5 to 7.3 cm [2.2 to 2.9 inches]), weight (15 to 27.7 kg [33 to 61 lbs]), and BMI (1.9 to 6.8 kg/m2) were statistically significant (p<0.001). These differences were especially pronounced for patients with FTDSBS who did not have an identifiable underlying spinal CSF leak. DISCUSSION: A distinctive body habitus consisting of tall stature and obesity is common among patients with FTDSBS especially among those who do not have an identifiable underlying spinal CSF leak. This may help generate hypotheses regarding the pathophysiology and eventual treatment of this devastating disorder.