Preprint Dysautonomia and small fiber neuropathy in post-COVID condition and Chronic Fatigue Syndrome, 2023, Azcue

Free:
https://www.researchsquare.com/article/rs-3388628/v1

Dysautonomia and small fiber neuropathy in post-COVID condition and Chronic Fatigue Syndrome

Naiara Azcue1

Rocio Del Pino2

Marian Acera1

Tamara Fernandez Valle1

Naia Ayo Mentxakatorre1

Tomás Pérez Concha3

Ane Murueta-Goyena4

Jose Vicente Lafuente4

Álvaro Prada-Iñurrategui5

Adolfo López de Munain6

Guillermo Ruiz-Irastorza1

Daniel Martín-Iglesias1

Laureano Ribacoba3

Iñigo Gabilondo1

Juan Carlos Gómez-Esteban1

Beatriz Tijero-Merino1

1 Biocruces Bizkaia Health Research Institute: Instituto de Investigacion Sanitaria Biocruces Bizkaia,

2 IIS Biocruces Bizkaia: Instituto de Investigacion Sanitaria Biocruces Bizkaia,

3 Cruces University Hospital: Hospital Universitario Cruces,

4 UPV/EHU: Universidad del Pais Vasco,

5 Hospital de Donostia: Hospital Universitario de Donostia,

6 Donostia Ospitalea: Hospital Universitario de Donostia

https://doi.org/10.21203/rs.3.rs-3388628/v1

This work is licensed under a CC BY 4.0 License

Background
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and post-COVID condition can present similarities such as fatigue, brain fog, autonomic and neuropathic symptoms.

Methods
The study included 87 patients with post-COVID condition, 50 patients with ME/CFS, and 50 HC. The hemodynamic autonomic function was evaluated using the deep breathing technique, Valsalva maneuver, and Tilt test. The presence of autonomic and sensory small fiber neuropathy (SFN) was assessed with the Sudoscan and with heat and cold evoked potentials, respectively. Finally, a complete neuropsychological evaluation was performed. The objective of this study was to analyze and compare the autonomic and neuropathic symptoms in post-COVID condition with ME/CFS, and healthy controls (HC), as well as, analyze the relationship of these symptoms with cognition and fatigue.

Results
Statistically significant differences were found between groups in heart rate, with ME/CFS group presenting the highest (H = 18.3; p ≤ .001). The Postural Orthostatic Tachycardia Syndrome (POTS), and pathological values in palms on the Sudoscan were found in 31% and 34% of ME/CFS, and 13.8% and 19.5% of post-COVID patients, respectively. Concerning evoked potentials, statistically significant differences were found in response latency to heat stimuli between groups (H = 23.6; p ≤ .01). Latency was highest in ME/CFS, and lowest in HC. Regarding cognition, lower parasympathetic activation was associated with worse cognitive performance.

Conclusions
Both syndromes were characterized by inappropriate tachycardia at rest, with a high percentage of patients with POTS. The prolonged latencies for heat stimuli suggested damage to unmyelinated fibers. The higher proportion of patients with pathological results for upper extremities on the Sudoscan suggested a non-length-dependent SFN.

 

"Patients diagnosed of ME/CFS should be previously diagnosed or meet the Fukuda et al.(6) criteria at the evaluation time."

 

Now published:
https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04678-3

 

ME Research UK

Many individuals with ME/CFS report pain as a major symptom. Pain is a key feature of small fibre neuropathy – a comorbidity of ME/CFS. This condition is also associated with a wide range of other symptoms, such
as ‘pins and needles’ and gastrointestinal issues.

Read more about small fibre neuropathy:
https://tinyurl.com/bdw7ey7h