Influence of Sport on Autonomic Dysreflexia of a Patient with Spinal

Cord Injury

Laura Bellintani de Freitas

, Rafaella Camilo de Oliveira

, Bruna Valentina Zuchatti

Ed Wilson Ferrari Junior

, Orcizo Francisco Silvestre

and Alberto Cliquet Junior

Faculty of Medical Sciences, UNICAMP - State University of Campinas, SP, Brazil

Faculty of Nursing, UNICAMP - State University of Campinas, SP, Brazil

Keywords: Spinal Cord Injury, Sport, Tetraplegia, Autonomic Dysreflexia.

Abstract: Spinal Cord Injury (SCI) causes loss of motor, sensory and autonomic functions below the injured level. The

increase in the number of cases of SCI, the main cause being motor vehicle accidents, and the social impact

that this condition causes makes the study on this condition very relevant. SCI brings physiological changes

and physical adaptations to the individual, such as cardiovascular problems and increased blood pressure due

to lacking of the sympathetic nervous system, known as autonomic dysreflexia (AD). Topographic

observation of the retina can help to understand the change that occurs in the autonomic response of these

individuals. The objective of the study was to analyze the vasculature changes in SCI with AD in athletes and

non-athletes, through retinal photography of these individuals. Retinal photographs were taken of 40 subjects

participating in the research, and these were divided into 4 groups: non-athletes with AD, athletes with AD,

SCI without AD, individuals without SCI. We can conclude that there is a higher prevalence of vascular

changes in patients with AD, especially in the athlete group.

1 INTRODUCTION

Spinal Cord Injury (SCI) is characterized by

disruption of afferent and efferent nerve

communication between the brain and the peripheral

nervous system, which leads to loss or reduction of

body function below the damaged level. SCI may be

complete or incomplete. Complete injury occurs

when there is no neurological function mediated by

the spinal cord below the level of injury. Incomplete

lesion occurs when there is at least some function

such as an intact sensation or as light distal motor

function (Eckert & Martin, 2017). More than half of

the individuals with SCI have the complete lesion,

which leads to total loss of sensitivity and

movements. The condition is classified as paraplegia

or tetraplegia, which are distinguished by the level of

the spinal cord affected by the injury (Holmes, 2017).

The term tetraplegia refers to the decrease or total

https://orcid.org/0000-0003-0213-4013

https://orcid.org/0000-0002-2868-6601

https://orcid.org/0000-0002-9288-3394

https://orcid.org/0000-0002-6870-4528

https://orcid.org/0000-0001-8537-4906

https://orcid.org/0000-0002-9893-5204

loss of motor and sensory functions of the cervical

segments, while the term paraplegia describes the loss

of motor and sensory functions of the thoracic,

lumbar and sacral segments.

The number of people with spinal cord injury has

grown over time, both in incidence and prevalence.

The main causes of injury are motor vehicle

accidents, followed by falls from heights and

firearms. The increase in the prevalence of

comorbidities is a consequence of the longer survival

of these patients due to the better preparation of pre-

hospital care with polytraumatized patients. The

world average of cases is 15 to 40/million inhabitants.

This high prevalence added to the social impact that

this condition brings to the lives of these people,

mostly young male adults still in the age group of 15-

40 years, (that is, the age of great productive

strength), makes the study necessary and relevant

(Casimiro et al., 2016).

Bellintani de Freitas, L., Camilo de Oliveira, R., Zuchatti, B., Ferrari Junior, E., Silvestre, O. and Cliquet Junior, A.

Inﬂuence of Sport on Autonomic Dysreﬂexia of a Patient with Spinal Cord Injury.

DOI: 10.5220/0012248700003587

In Proceedings of the 11th International Conference on Sport Sciences Research and Technology Support (icSPORTS 2023), pages 221-226

ISBN: 978-989-758-673-6; ISSN: 2184-3201

221

The autonomic nervous system is responsible for

controlling body homeorhesis. It is divided into

sympathetic and parasympathetic, who act in an

antagonistic and coordinated manners. In order for it

to be activated, actions of neurotransmitters are

necessary. Acetylcholine (Ach) is responsible for the

post-ganglion synapses of the parasympathetic

autonomic nervous system. When we refer to the

sympathetic autonomic nervous system, the

neurotransmitter responsible is norepinephrine, or

adrenaline. The sympathetic nervous system leads to

an increase in heart rate, respiratory rate, mydriasis

and a decrease in gastrointestinal functions. The

parasympathetic works in a contrary way, balancing

the effects.

SCI that occurs at or above T6 neurologic level

results in a syndrome called autonomic dysreflexia

(AD). AD is thus defined as acute hypertension

because sympathetic reflexes below the affected level

are no longer modulated. This syndrome is often

accompanied by baroreceptor-mediated bradycardia,

which leads to a short-term control of blood pressure.

It is precipitated by massive somatic stimulation,

which leads to vasoconstriction. As factors of

precipitation of the syndrome, we can cite the

distension of the bladder by accumulation of urine or

intestinal constipation. Systolic blood pressure can

reach high values, being characterized as

hypertensive crisis, thus being a medical emergency.

Other related symptoms are: headaches, excessive

sweating, hyperemia of the skin, blurred vision and

anxiety (Edahan and Rabcheysky, 2018).

The human retina can characterize diseases of the

eye and other systems such as the cardiovascular. The

retina is a highly vascularized tissue, and its

functioning can be drastically affected in the course

of vascular changes. The retinal vasculature, because

it allows the easy visualization of part of the human

circulation through its microvasculature, is

considered as a way to non-invasive vessel network

access, without the need for procedures and with the

use of technologies of simple complexity to access it.

Thus, retinography can be an instrument for early

identification of cardiovascular changes, one of the

consequences of autonomic dysreflexia in spinal cord

injuries. Quantitative measures of retinal vascular

topography have already been proposed as a way of

analyzing the effects of autonomic dysreflexia and its

relationship with the diagnosis of this condition. AD

can occur several times a day, depending on the

amount of stimuli, which would justify the structural

change of the peripheral vasculature and its

remodelation (Edahan and Rabcheysky, 2018).

Retinal vasculature changes caused by

uncontrolled arterial hypertension have already been

described in the literature. These are: change in the

branching pattern of the retinal vessels, change in

caliber, tortuosity, and branching angle (Dai et al.,

2020). In principle, the patterns of vascular changes

that uncontrolled chronic arterial hypertension can

cause would help define the pattern of autonomic

dysreflexia.

The analysis of the vascular topography of the

retina can help to understand the functioning of the

autonomic nervous system in SCI individuals that

have AD and understand the changes that arise from

repetitive stimuli, such as the practice of Paralympic

sports. In addition, it can facilitate the diagnosis of

this condition.

The diagnosis of the presence of AD is important

to manage the hypertensive crisis that these

individuals present, since it is differs from the

management of hypertensive crises of other causes. It

is based on the active search for precipitating factors

of the episode to eliminate this stimulus such as, the

emptying of the bladder. In addition, postural

maneuvers such as sitting or lifting the patient with a

straight back can help lower blood pressure from a

better hydrostatic distribution of blood in the

extremes (Edahan and Rabcheysky, 2018).

2 OBJECTIVES

This study aimed to analyze the differences in the

patterns of retinal structures of spinal cord injured

patients with autonomic dysreflexia with those

without alterations of the autonomic system. It seeks

to diagnose changes in the retinal arterial pattern of

patients with AD, physical activity practitioners and

non-athletes, through photographic analysis of the

retina.

Changes in the parameters of the retinal

vasculature are related to increased systemic blood

pressure. Changes in the autonomic nervous system

of these individuals lead to increased blood pressure.

The detection and quantification of affected

individuals can help to clarify the effect of AD on the

cardiovascular system.

The work counts on the cooperation of the Spinal

Cord Rehabilitation Outpatient Clinic- University

Hospital, the Biomechanics and Rehabilitation of the

Locomotor System Laboratory, Faculty of Medical

Sciences, both at The University of Campinas -

UNICAMP and the GIGANTES Paralympic Rugby

Team, from the city of Campinas, State of São Paulo.

icSPORTS 2023 - 11th International Conference on Sport Sciences Research and Technology Support

222

3 METHODS

40 individuals were recruited (n = 40), 30 individuals

with spinal cord injury and 10 without spinal cord

injury. Group A was composed of 11 SCI subjects

with AD, all non-athletes. Group B was composed of

8 athletes (tetraplegics) who practice Paralympic

Rugby. As control groups, 11 lower level paraplegic

individuals were selected, by definition without

autonomic dysreflexia, comprising Group C. A total

of 10 individuals without SCI comprised Group D.

Participants with previously diagnosed

cardiovascular disease, such as systemic arterial

hypertension, were excluded from the study.

Photographs of the retina were taken from a

portable retinographer of the company Phelcom

(Figure 1), which made it possible to collect the data.

The control groups were also photographed for

comparison

Figure 1: Photo of EYER, portable retinographer of the

company Phelcom (Phelcom.com/product/ever).

The caliber of retinal arterial vasculature with

uncontrolled hypertension was not significantly

influenced by systemic blood pressure at the time of

photography (Dai et al., 2020). This conclusion

corroborates the structure developed by this work,

since if the hypertensive peak momentarily altered the

vasculature, retinal photographs could be a

confounding element. Since the photograph is free of

momentary alteration, it became an instrument for

retrograde analysis of the pressure profile of the

analyzed individual. The analysis of retinal

photographs was carried out by two qualified

ophthalmologists, who diagnosed changes in patterns

compared to normality, based on changes previously

described in the literature. When the diagnostic

hypothesis diverged, a third ophthalmologist was

requested for the correct classification of patients.

The description of the changes found by them was

carried out. The Ethics Committee approved the

Project - CAAE number: 31510620.9.0000.5404. All

regulations regarding the ethical use of human

volunteers were followed. Furthermore, all

participants gave their written consent, thus allowing

the use the results obtained for further analysis and

the production of new data.

4 STATISTICAL ANALYSIS

The statistical analysis used the calculation of the

odds ratio for comparison between the 4 Groups (A,

B, C and D) to clarify the relationship between

autonomic dysreflexia and the chance of vasculature

changes. For instance, when comparing group A with

group C, shown on Table 2: (4*8) / (3*7) equals 1.52.

The epidemiological profile of groups A and B,

groups referring to individuals with high spinal cord

injuries and with the presence of autonomic

dysreflexia, was also described from the interview

with the participants (Table 1).

Table 1: Epidemiological profile of patients with autonomic

dysreflexia (athletes and non-athletes).

Injury

level

Age

(years)

Sex Trauma history Injury

time

(years)

C5 38 Female Automobile

Accident

C4 34 Male Automobile

Accident

T4 23 Male Automobile

Accident

C5 19 Male Diving Trauma 3

T3 49 Male Automobile

Accident

C5 49 Male Automobile

Accident

T4 54 Male Automobile

Accident

T4 20 Male Automobile

Accident

T4 38 Male Firearm injury 12

C3 45 Male Firearm injury 23

C5 50 Male Fall from Height 18

C6 33 Male Diving Trauma 11

T2 38 Male Automobile

Accident

C7 33 Male Automobile

Accident

C5 30 Male Automobile

Accident

C7 40 Male Diving Trauma 13

C5 34 Male Diving Trauma 16

C6 34 Male Automobile

Accident

C5 43 Male Diving Trauma 20

Inﬂuence of Sport on Autonomic Dysreﬂexia of a Patient with Spinal Cord Injury

223

The diagnosis (Table 2) of changes in the arteries

of the retina: groups A, B, C and D were divided into:

with retinal vasculature alterations and without retinal

vasculature alterations

Table 2: Presence or absence of retinal changes in the

analyzed groups:

With

Alterations

Without

Alterations

Total

Group A 4 7 11

Group B 4 4 8

Group C 3 8 11

Group D 2 8 10

Group A: non-athletes with autonomic dysreflexia

Group B: athletes with autonomic dysreflexia

Group C: non-athletes without autonomic dysreflexia

Group D: individuals without spinal cord injury.

5 RESULTS

According to the epidemiological profile of patients

with autonomic dysreflexia found, we can conclude

that there is a higher prevalence of spinal cord injuries

in males, while automobile accident was the most

prevalent mechanism of trauma. The mean age of the

individuals was 35.2 years old. Mean years of injury

was 12.3 years (Figure 2).

Figure 2: Distribution by sex, age and years of injury.

The retinal changes found and described in spinal

cord injured patients with autonomic dysreflexia

were: arteriolar narrowing, arteriolar tortuosity and

pathological AV crossing. These alterations were also

found in the control groups, but the number of

individuals with alterations in the group with AD was

higher. In addition, cases with two or more

overlapping changes were present in the group with

AD, but this was not observed in the control groups

(Figures 3 to 7).

Figure 3: Arteriolar tortuosities and arteriolar narrowing.

Figure 4: Pathological AV crossing.

Figure 5: Arteriolar narrowing.

Figure 6: Retina without vascular changes (control group).

Figure 7: Retina without vascular changes (control group).

Considering the groups with AD non-athletes and

athletes together (groups A and B), we concluded that

there is a 2.33 times higher chance of developing

retinal artery changes in these individuals, compared

to individuals without AD (Groups C and D).

Considering only individuals with AD, when we

analyzed only groups A and B, we noticed a chance

of changes of 1.75 times more in Group B (athletes),

compared to Group A (non-athletes).

Comparing only individuals with spinal cord

injury that were non-athletes, we noticed a chance of

1.52 times more changes in Group A (with AD),

compared to Group C (without AD).

icSPORTS 2023 - 11th International Conference on Sport Sciences Research and Technology Support

224

Table 3: statistical analysis of the comparison between

groups A, B, C and D.

(A + B) × (C + D) A × B A × C

Odds Ratio (OR) 2.33 1.75 1.52

6 DISCUSSION

From our analysis, it was possible to infer that there

is a higher chance of occurrence of changes in retinal

arterial vasculature in individuals with AD compared

to those who do not present this comorbidity.

The chance of occurrence increases in individuals

with AD who practice physical exercise, compared to

individuals who do not practice sport.

When we analyze only the groups of non- athletes

with SCI, we see that the chance of occurrence is still

greater than 1, thus meaning an increase in

occurrence, but it is still lower than that present in the

athletes.

The results obtained lead to the discussion that it

is possible to have a higher occurrence of retinal

artery changes in these patients. Sport can influence

the occurrence of these vascular changes, and this

may be due to the higher frequency of stimuli that

these individuals are exposed to, due to regular sports.

This study demonstrated the identifiable patterns

in the retina of individuals with such condition, which

may lead in the future to an early diagnosis from the

analysis of the back of the eye from these individuals.

Patterns of alterations such as arteriolar narrowing,

arteriolar tortuosity and pathological AV crossing

were described. These changes were previously

described also in patients with Chronic Systemic

Arterial Hypertension (Ponto et al., 2017). Since the

changes in these arteries reflect systemic changes, it

can be inferred that these patients are more prone to

vascular diseases due to the presence of autonomic

dysreflexia.

This study can serve as a warning about the

increased risk of cardiovascular diseases that

autonomic dysreflexia could bring, presenting as

changes in the retinal vasculature. These can be

considered as target organ lesions, and thus retinal

photography can be a screening method for

comorbidity, enabling the individual to detect early

possible complications of cardiovascular disease that,

as in chronic arterial hypertension, can manifest as

ischemic or hemorrhagic stroke, coronary artery

disease, peripheral vascular disease, and kidney

disease (Oparil et al., 2018).

7 CONCLUSION

The current study was limited by the small number of

participants, especially considering the group of

athletes. More studies are needed, with larger

numbers of individuals, to prove the association that

this work aimed to demonstrate. In the future, early

diagnosis of AD through ophthalmoscopy in these

patients may be beneficial for early detection of the

condition and better monitoring and progression of

comorbidity.

Sport in this study was considered as a risk factor,

but we did not aim to discourage its practice. It has

already proven to be beneficial for this portion of the

population, both in terms of quality of life and health.

The practice of sport leads to a lower risk of

developing shoulder injuries, especially on the

acromioclavicular joint (Medina et al., 2015). In

addition, it is undeniable that sport serves as a form

of psychological support and social interaction for

this population. Our main objective is to stimulate the

regular follow-up of these patients, athletes or not, for

early detection and control of future changes, since all

individuals with AD are exposed to greater risks than

individuals without AD.

Since the results are similar to those found in the

analysis of retinal patterns of chronic hypertensive

patients - pathological AV crossing, tortuosities,

arteriolar narrowing, we can conclude that although

autonomic dysreflexia crises are an acute condition,

the condition can be considered as chronic. This is

explained by the characteristic of AD of high degree

of daily recurrence, justifying that acute pressure

peaks behave as chronic throughout the life of these

patients. Monitoring blood pressure during

paralympic sports involving high lesioned spinal cord

parathletes, tetraplegics in particular, is highly

recommended.

ACKNOWLEDGMENTS

The State of São Paulo Foundation for Research-

FAPESP, The National Council for Scientific and

Technological Development-CNPq (Brasilia) and the

Ministry of Education - CAPES

REFERENCES

Eckert, M. J., & Martin, M. J. (2017). Trauma: spinal cord

injury. Surgical Clinics, 97(5), 1031-1045.

Inﬂuence of Sport on Autonomic Dysreﬂexia of a Patient with Spinal Cord Injury

225

Holmes, D. (2017). Spinal-cord injury: spurring regrowth.

Nature, 552(7684), S49.

Casimiro, F. D. G., Oliveira, G. F. D., Tenório, P. H. D. M.,

Gagliardi, I. D. C., Zoppi Filho, A., & Cliquet Junior,

A. (2016). Clinical and radiographic evaluation of

elbows from spinal cord injuried patients. Acta

ortopedica brasileira, 24, 77-80.

Eldahan, K. C., & Rabchevsky, A. G. (2018). Autonomic

dysreflexia after spinal cord injury: Systemic

pathophysiology and methods of management.

Autonomic Neuroscience, 209, 59-70.

Dai G, Dai, G., He, W., Xu, L., Pazo, E. E., Lin, T., Liu, S.,

& Zhang, C. (2020). Exploring the effect of

hypertension on retinal microvasculature using deep

learning on East Asian population. PloS one, 15(3),

e0230111.

Ponto, K. A., Werner, D. J., Wiedemer, L., Laubert-Reh,

D., Schuster, A. K., Nickels, S., ... & Mirshahi, A.

(2017). Retinal vessel metrics: normative data and their

use in systemic hypertension: results from the

Gutenberg Health Study. Journal of hypertension,

35(8), 1635-1645.

Oparil, S., Acelajado, M. C., Bakris, G. L., Berlowitz, D.

R., Cífková, R., Dominiczak, A. F., Grassi, G., Jordan,

J., Poulter, N. R., Rodgers, A., & Whelton, P. K. (2018).

Hypertension. Nature reviews. Disease primers, 4,

18014

Medina, G. I. S., Jesus, C. L. M., Ferreira, D. M., Pacheco,

E. M. B., Beraldo, G. L., de Franca Urquiza, F., &

Cliquet, A. (2015). Is sport practice a risk factor for

shoulder injuries in tetraplegic individuals?. Spinal

Cord, 53(6), 461-466.

icSPORTS 2023 - 11th International Conference on Sport Sciences Research and Technology Support

226