title: A retrospective review of autonomic screening tests conducted at a Tertiary General Hospital.
abstract: Autonomic screening tests (AST) are useful for assessing autonomic dysfunction. Our aim was to delineate the referral pattern, abnormalities, technical difficulties and final diagnoses of ASTs at a Tertiary General Hospital. Referring diagnoses was classified into: orthostatic symptoms, assessment of known/suspected disease associated with dysautonomia, thermoregulatory complaints and neurological disorders. Medication history, patient cooperation and test results were collated. Usefulness of AST in answering the clinical questions was ranked on a 3-point scale. 248 patients were studied. Orthostatic symptoms were the commonest referring diagnosis (71.4%) followed by assessment of a known/suspected disease associated with dysautonomia (13.3%), thermoregulatory complaints (7.7%) and neurological disorders (7.3%). 49.6% of ASTs were abnormal, 40.7% were normal and 9.7% were inconclusive. The first 2 referral categories had the highest proportion of abnormal ASTs while only 5.3% of patients with thermoregulatory complaints had abnormal AST. The most frequent final diagnosis was orthostatic hypotension (OH). It was seen in 31.7% of the cohort; however, 41% of these were attributed to medications. With regard to answering the clinical question, ASTs were very helpful in 56.0% and not helpful in 9.3%. 58.0% of inconclusive ASTs were attributed to poor performance of test maneuvers, 8.0% to medications, 17.0% to both and 17.0% to irregular heart rhythms and pacemakers. 34.7% of patients with diabetes mellitus and 38.2% of patients with Parkinsonism had signs of autonomic dysfunction. About 7% of diabetic and a quarter of Parkinsonism patients had OH secondary to medications. We believe these findings can contribute to better application of AST.
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore. Electronic address: odeliakoh@gmail.com.
authors.forename: Odelia
authors.initials: O
authors.lastname: Koh
authors.affiliation: National Neuroscience Institute, Singapore.
authors.forename: Thirugnanam
authors.initials: T
authors.lastname: Umapathi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006769:Hospitals, General / Q000706:statistics & numerical data*; D006801:Humans; D007024:Hypotension, Orthostatic / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data; D012017:Referral and Consultation; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology; D062606:Tertiary Care Centers / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Autonomic dysfunction; Autonomic neuropathy; Autonomic screening test; Orthostatic hypotension