Autonomic dysfunction in multiple system atrophy (MSA) includes orthostatic hypotension, urinary dysfunction, constipation, erectile dysfunction, thermoregulation (sweating and temperature intolerance), pupil function, respiration, etc. This email focuses on sweating in MSA.
Mayo Rochester has published a major paper on anhidrosis (lack of sweating) in 232 cases of multiple system atrophy (MSA). Quite a few of our local MSA support group members have been seen at Mayo Rochester, and a few were seen during the time period of the study — between 2005 and 2010.
Thirty-four of the 232 patients eventually had autopsy-proven MSA. We aren’t told if any of the 34 brain donation cases had something other than MSA, so I think we can assume not. Interestingly, some of the 34 with autopsy-proven MSA had close to normal sweat function.
Brain Support Network has helped quite a few MSA families donate a loved ones brain to Mayo Rochester but I’m not sure there were any during that five-year time period of the study.
I’m unclear why it takes Mayo Rochester seven years to publish data from 2005 to 2010. At that rate, progress is mud-slow.
I’ve copied the abstract of the anhidrosis paper below. The full paper is available at no charge online at the Movement Disorders Journal website:
(The paper does have some cool images of anhidrosis patterns in MSA.)
The researchers drew these three conclusions:
“(1) sudomotor dysfunction is almost invariably present in MSA and even more common and severe in MSA-parkinsonism than MSA-cerebellar;
(2) a preganglionic pattern of sweat loss is common in MSA; however, pre- and postganglionic abnormalities may coexist; and
(3) the increasing frequency of postganglionic sudomotor dysfunction over time suggests involvement of postganglionic fibers or sweat glands later in the disease course.”
Here are some definitions just to understand these conclusions —
* sudomotor: describes anything that stimulates the sweat glands
* preganglionic: something that originates in the brainstem or the spinal cord
* postganglionic: something that runs from the ganglion elsewhere; exists outside the central nervous system
These MSA patients at Mayo Rochester were given two tests to determine if the problem (lesion) was in the preganglionic or postganglionic part of the autonomic nervous system:
* thermoregulatory sweat testing (TST), a test of autonomic function, and
* quantitative sudomotor axon reflex testing [QSART], a test of postganglionic sudomotor function
The researchers said: “[An] area of absent sweating on TST in an area with a normal QSART response would indicate a preganglionic lesion. Conversely, a reduced or absent QSART indicates a postganglionic lesion.”
Why was this study done? The researchers said: “Although hypo- or anhidrosis in MSA is well recognized, the degree, pattern, lesion site, and temporal evolution of sudomotor dysfunction in MSA has not been systematically evaluated in a large patient cohort.”
An accompanying editorial in the March 2017 Movement Disorders Journal is titled the “many faces of autonomic failure in multiple system atrophy” (MSA). According to the editorialists, in the anhidrosis study, researchers “show abnormal thermoregulatory sweat testing in 95% of all assessed MSA patients. Remarkably, only 16% of MSA patients complained about sweating symptoms.”
The short editorial looks briefly at other techniques to assess sweat dysfunction. See:
OK, I think that’s enough for most of us….
Anhidrosis in multiple system atrophy involves pre- and postganglionic sudomotor dysfunction
Elizabeth A. Coon MD, Robert D. Fealey MD, David M. Sletten, Jay N. Mandrekar PhD, Eduardo E. Benarroch MD, Paola Sandroni MD, PhD, Phillip A. Low MD, Wolfgang Singer MD
Movement Disorders Journal, Vol 32, Issue 3, March 2017, pages 397-404
First published online: 10 November 2016
The objective of this study was to characterize the degree, pattern, lesion site, and temporal evolution of sudomotor dysfunction in multiple system atrophy (MSA) and to evaluate differences by parkinsonian (MSA-parkinsonism) and cerebellar (MSA-cerebellar) subtypes.
All cases of MSA evaluated at Mayo Clinic Rochester between 2005 and 2010 with postganglionic sudomotor testing and thermoregulatory sweat test were reviewed. Pattern and lesion site (preganglionic, postganglionic, or mixed) were determined based on thermoregulatory sweat test and postganglionic sudomotor testing.
The majority of the 232 patients were MSA-parkinsonism (145, 63%). Initial postganglionic sudomotor testing was abnormal in 59%, whereas thermoregulatory sweat test was abnormal in 95% of all patients. MSA-parkinsonism patients were more likely to have an abnormal thermoregulatory sweat test compared with MSA-cerebellar (98% versus 90%, P = 0.006) and had a higher mean percentage of anhidrosis (57%) compared with MSA-cerebellar (48%; P = 0.033). Common anhidrosis patterns were regional (38%) and global (35%). The site of the lesion was preganglionic in 47% and mixed (preganglionic and postganglionic) in 41%. The increase in anhidrosis per year was 6.2% based on 70 repeat thermoregulatory sweat tests performed on 29 patients. The frequency of postganglionic sudomotor abnormalities increased over time.
Our findings suggest: (1) sudomotor dysfunction is almost invariably present in MSA and even more common and severe in MSA-parkinsonism than MSA-cerebellar; (2) a preganglionic pattern of sweat loss is common in MSA; however, pre- and postganglionic abnormalities may coexist; and (3) the increasing frequency of postganglionic sudomotor dysfunction over time suggests involvement of postganglionic fibers or sweat glands later in the disease course.
© 2016 International Parkinson and Movement Disorder Society