There’s been quite a bit published this year about those with “Pure Autonomic Failure” converting to Parkinson’s Disease (PD), Dementia with Lewy Bodies (DLB), or Multiple System Atrophy (MSA). (All three disorders are alpha-synucleinopathies.)
PAF is a disorder of the autonomic system. The autonomic system controls things that the body generally handles automatically such as blood pressure, heart rate, eye blink, body temperature, sweating, digestion, etc.
This article, published in February 2017, is authored by the Autonomic Disorders Consortium, a group made up of the key autonomic specialists in the US.
In this study of 74 subjects at five US medical centers (NYU, Vanderbilt, Mayo Rochester, NIH, and Harvard), about one-third (34%) developed DLB (n=13), PD (n=6), or MSA (n=6) over four years. Overall, 14% of people converted from PAF to one of the three alpha-synculein disorders each year. Many of those who converted had REM sleep behavior disorder (RBD).
Other symptoms were associated with who got MSA, DLB, or PD:
* “Patients who phenoconverted to multiple system atrophy had younger age at onset of autonomic failure, severe bladder/bowel dysfunction, preserved olfaction, and a cardiac chronotropic response upon tilt > 10 beats per minute.” The “younger age” was early 50s. On average, those in the PAF group who converted to MSA had PAF symptoms for fewer than five years.
* “Those who phenoconverted to Parkinson disease or dementia with Lewy bodies had decreased olfaction, a lesser chronotropic response to tilt, and a longer duration of illness.” “Longer duration of illness” refers to the fact that, on average, those in the PAF group who converted to PD or DLB had PAF symptoms for nearly ten years.
And: “The small group of patients retaining the pure autonomic failure phenotype had very low plasma norepinephrine levels, slow resting heart rate, no REM sleep behavior disorder, and preserved smell.”
Here’s a link to the full article (available at no charge online):
www.ncbi.nlm.nih.gov/pmc/artic
The abstract is copied below.
Robin
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Annals of Neurology. 2017 Feb;81(2):287-297.
Natural history of pure autonomic failure: A United States prospective cohort.
Kaufmann H, Norcliffe-Kaufmann L, Palma JA, Biaggioni I, Low PA, Singer W, Goldstein DS, Peltier AC, Shibao CA, Gibbons CH, Freeman R, Robertson D; Autonomic Disorders Consortium.
Abstract
OBJECTIVE:
To define the clinical features and biomarkers that predict which patients with pure autonomic failure will develop Parkinson disease, dementia with Lewy bodies, or multiple system atrophy.
METHODS:
One hundred patients who presented with pure autonomic failure were recruited at 5 medical centers in the United States. Seventy-four patients agreed to be followed prospectively. Patients underwent clinical evaluations including neurological rating scales, sleep questionnaires, smell test, and sympathetic and parasympathetic cardiovascular autonomic function tests.
RESULTS:
At enrollment, patients were 68 ± 12 years old (median ± interquartile range) and had had autonomic failure for 5 ± 7 years. Within 4 years of follow-up, 25 of 74 subjects (34%) developed dementia with Lewy bodies (n = 13), Parkinson disease (n = 6), or multiple system atrophy (n = 6). The presence of probable rapid eye movement (REM) sleep behavior disorder was strongly associated with the development of a manifest central nervous system (CNS) synucleinopathy (odds ratio = 7.1). Patients who phenoconverted to multiple system atrophy had younger age at onset of autonomic failure, severe bladder/bowel dysfunction, preserved olfaction, and a cardiac chronotropic response upon tilt > 10 beats per minute. Those who phenoconverted to Parkinson disease or dementia with Lewy bodies had decreased olfaction, a lesser chronotropic response to tilt, and a longer duration of illness. The small group of patients retaining the pure autonomic failure phenotype had very low plasma norepinephrine levels, slow resting heart rate, no REM sleep behavior disorder, and preserved smell.
INTERPRETATION:
Patients presenting with pure autonomic failure are at high risk of phenoconverting to a manifest CNS synucleinopathy. Specific clinical features predict future diagnosis.
© 2017 American Neurological Association.
PMID: 28093795
www.ncbi.nlm.nih.gov/pubmed/28
Robin