Among patients with at least a 5-year history of idiopathic autonomic failure, 32% phenoconverted to a CNS synucleinopathy, with early urinary dysfunction and REM sleep behavior disorder predicting conversion.
Cohort (n=50)
No
What are the clinical and instrumental predictors of phenoconversion to CNS synucleinopathies in patients with idiopathic autonomic failure?
In patients with idiopathic autonomic failure, early onset of urinary dysfunction, REM sleep behavior disorder, and a Valsalva ratio ≥1.25 predict phenoconversion to CNS synucleinopathies.
Objective To retrospectively describe clinical and instrumental features of a cohort of patients with at least a 5-year history of idiopathic autonomic failure (IAF) longitudinally evaluated at the Autonomic Unit of the University of Bologna (IAF-Bo cohort). Methods We identified patients with at least a 5-year history of IAF who were referred to our department from 1989 to 2016 and evaluated at least once a year during the disease course. Clinical and instrumental data were collected from medical records. Clinical variables were categorized as early if presenting within 3 years from disease onset. Predictors associated with conversion to other synucleinopathies were identified in a Cox regression analysis. Results The IAF-Bo cohort included 50 patients (39 male, 19 deceased at the last follow-up). At the last follow-up visit, 34 patients retained IAF phenotype (ncIAF group), while 16 developed a CNS synucleinopathy (converters group). Specific clinical and instrumental features were represented differently in the converters and ncIAF groups. The converters group showed a higher risk of death than the ncIAF group. Early onset of urinary dysfunction, early onset of REM sleep behavior disorder, and a Valsalva ratio ≥1.25 were identified as variables associated with phenoconversion. Conclusions This is one of the largest studies on the natural history of a cohort of patients with at least a 5-year history of IAF, showing a percentage of phenoconversion of 32%. We demonstrated that specific clinical and instrumental features entail an increased probability of phenoconversion. These findings could contribute to a better definition of the nature of IAF and to the identification of early markers of phenoconversion.
Spigset et al. (Sat,) conducted a cohort in Idiopathic autonomic failure (IAF) (n=50). Idiopathic autonomic failure was evaluated on Phenoconversion to a CNS synucleinopathy. Among patients with at least a 5-year history of idiopathic autonomic failure, 32% phenoconverted to a CNS synucleinopathy, with early urinary dysfunction and REM sleep behavior disorder predicting conversion.