Trial Report Mismatch between subjective and objective dysautonomia, 2024, Novak, Systrom et al

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https://www.nature.com/articles/s41598-024-52368-x

• Article
• Open access
• Published: 30 January 2024

Mismatch between subjective and objective dysautonomia

• Peter Novak,
• David M. Systrom,
• Sadie P. Marciano,
• Alexandra Knief,
• Donna Felsenstein,
• Matthew P. Giannetti,
• Matthew J. Hamilton,
• Jennifer Nicoloro-SantaBarbara,
• Tara V. Saco,
• Mariana Castells,
• Khosro Farhad,
• David M. Pilgrim &
• William J. Mullally

Scientific Reports volume 14, Article number: 2513 (2024)

Abstract

Autonomic symptom questionnaires are frequently used to assess dysautonomia.

It is unknown whether subjective dysautonomia obtained from autonomic questionnaires correlates with objective dysautonomia measured by quantitative autonomic testing.

The objective of our study was to determine correlations between subjective and objective measures of dysautonomia.

This was a retrospective cross-sectional study conducted at Brigham and Women’s Faulkner Hospital Autonomic Laboratory between 2017 and 2023 evaluating the patients who completed autonomic testing. Analyses included validated autonomic questionnaires [Survey of Autonomic Symptoms (SAS), Composite Autonomic Symptom Score 31 (Compass-31)] and standardized autonomic tests (Valsalva maneuver, deep breathing, sudomotor, and tilt test).

The autonomic testing results were graded by a Quantitative scale for grading of cardiovascular reflexes, sudomotor tests and skin biopsies (QASAT), and Composite Autonomic Severity Score (CASS).

Autonomic testing, QASAT, CASS, and SAS were obtained in 2627 patients, and Compass-31 in 564 patients.

The correlation was strong between subjective instruments (SAS vs. Compass-31, r = 0.74, p < 0.001) and between objective instruments (QASAT vs. CASS, r = 0.81, p < 0.001).

There were no correlations between SAS and QASAT nor between Compass-31 and CASS.

There continued to be no correlations between subjective and objective instruments for selected diagnoses (post-acute sequelae of COVID-19, n = 61; postural tachycardia syndrome, 211; peripheral autonomic neuropathy, 463; myalgic encephalomyelitis/chronic fatigue syndrome, 95; preload failure, 120; post-treatment Lyme disease syndrome, 163; hypermobile Ehlers-Danlos syndrome, 213; neurogenic orthostatic hypotension, 86; diabetes type II, 71, mast cell activation syndrome, 172; hereditary alpha tryptasemia, 45).

The lack of correlation between subjective and objective instruments highlights the limitations of the commonly used questionnaires with some patients overestimating and some underestimating true autonomic deficit.

The diagnosis-independent subjective–objective mismatch further signifies the unmet need for reliable screening surveys.

Patients who overestimate the symptom burden may represent a population with idiosyncratic autonomic-like symptomatology, which needs further study.

At this time, the use of autonomic questionnaires as a replacement of autonomic testing cannot be recommended.

 

Looks like an interesting study with a large sample sizes and multiple illnesses.

But you can read the results two-ways: the questionnaires might be unreliable indicators of objective autonomic testing, or the things measured with the objective tests do a poor job at explaining the patients orthostatic symptoms...

 

These questionnaires are usually used to support Conclusions that patients (including individuals) have objective, physiological, autonomic problems. And I don’t think it’s now safe to draw such conclusions.

TBH, I’d always assumed that someone had done this kind of work originally to validate the questionnaires.

Explaining the Autonomic, — like symptoms is a separate issue,though still very important. But this study seems to move the field forward.

 

I haven't read the paper yet, but it's unlikely the objective tests are measuring reduced cerebral blood flow, but rather relying on the proxy cardiovascular changes such as tachycardia and orthostatic hypotension.

 

The paper does write: "Recorded signals included electrocardiogram, blood pressure, respiratory movement, end-tidal CO2, respiratory rate, and CBFv in the middle cerebral artery using Transcranial Doppler."

 

Or a third way - which might be both - which is that 'dysautonomia' is not a well thought out term. Whatever the tests are measuring it does not seem to be what is bothering the patients.

Rather than talk of dysautomnomia it might be better to stick to specific concepts like postural hypotension or inappropriate tachycardia. Maybe the problem is that if you chuck all the measures into a single questionnaire or a single 'objective measure' anything of any interest gets lost.

 

Bizarre conclusions. The symptoms reported by patients in questionnaires may be caused by a totally different mechanism that has nothing to do with autonomic dysfunction.

 

I'm confused. I thought that postural hypotension and POTS could be objectively measured e.g. by the NASA lean test.

 

Even more likely: both. Autonomic dysfunction and orthostatic intolerance are complex systemic problems, and reducing them to those few data points isn't that much better than randomness or using probing hover hands.

 

Yes, these things can in theory be measured objectively but maybe the problem is trying to devise an objective test for 'dysautonomia' rather than something more specific like these. I have never been quite sure what dysautnomia means. The increase in heart rate in POTS suggests that the autonomic response is functioning - and that something else I wrong I think.

 

Got it now, thanks.