To describe cognitive profile in a cohort of Pure Autonomic Failure (PAF) patients and its association to phenotype conversion.

Prospective studies on patients with isolated autonomic failure revealed that some patients maintain a PAF phenotype for many years, while others progress with motor or cognitive deficits. While motor changes were exhaustively evaluated in previous studies, cognitive functions were marginally examined to detect presence/absence of dementia. However mild cognitive deficits may represent signs of disease progression as well.

From the well-characterized IAF-BO cohort, we selected patients who meet PAF criteria and underwent a comprehensive neuropsychological evaluation (NPS).

Twenty-four patients performed NPS (mean age 59,75±8,66 years; disease duration 11,76±5,43 years).
Although nobody had subjective complains, 10 out of 24 patients (41,7%) were cognitively impaired (CI), 9 on attentive-executive tests and 1 on short-term verbal memory.
5 out of 10 patients meet criteria for mild cognitive impairment (MCI).
No differences in clinical variables, cardiovascular autonomic function parameters or sleep disturbances were found between cognitive normal, CI and MCI patients.
Patients with video-polysomnography documented REM sleep Behavior Disorder (RBD) performed significantly worse on attentive tasks (Barrage point score p<0,03; Stroop time score p<0,02) compared to patients without RBD.
After 2-8 years of observation, 3 patients converted to overt synucleinopathies. Nobody was cognitive impaired at first evaluation, while all displayed cognitive deficits (Stroop test, Verbal Analogies) at conversion-time.
None of CI patients converted during follow-up, that comes up to 5 years for 7 patients.

A comprehensive neuropsychological evaluation disclosed an attentive-executive dysfunction in 37,5% of PAF patients.
Cognitive deficits are not strictly associated with phenotype conversion over 5 years.
Further evaluations are mandatory to disclose the cause of cognitive impairment in PAF.