scholarly journals THE UTILITY OF PUPILLARY LIGHT REFLEX AS AN OBJECTIVE BIOMARKER OF ACUTE CONCUSSION IN THE ADOLESCENT ATHLETE

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0015
Author(s):  
Olivia E. Podolak ◽  
Nabin Joshi ◽  
Kenneth Ciuffreda ◽  
Fairuz Mohamed ◽  
Shelly Sharma ◽  
...  
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Pupil Diameter ◽  
Light Stimulus ◽  
Pupillary Light Reflex ◽  
Post Injury ◽  
Light Reflex ◽  
Autonomic Nervous ◽  
Pupillary Light ◽  
Over Time

Background: Visual deficits and autonomic dysfunction have been well recognized following pediatric concussion. Testing of the pupillary light reflex (PLR) is a simple, non-invasive, and objective approach to examine the autonomic nervous system by accessing the brain pathways. The aim of this study was to objectively evaluate adolescent pupillary responses to a light stimulus after a physician-diagnosed concussion and compare them to baseline responses. Methods: In this prospective cohort study, PLR was assessed in 135 adolescent athletes (ages 14-18) during their sport pre-season. All of the athletes were not recovering from a concussion at the time of their baseline assessment. Within this cohort, seven athletes (ages 14-17) sustained a concussion during their sport season and had longitudinal post-injury assessments of PLR through their recovery. The PLR was obtained in response to a brief step-input (0.8 seconds) white light stimulus using a hand-held pupillometer (stimulus recording duration= 5 seconds, light intensity= 150 lux). Pre-set and automated device-generated parameters used for analysis include the minimum and maximum pupil diameter, response amplitude and latency, mean constriction and dilation velocities and the maximum constriction velocity of the eye in response to a light stimulus. During each assessment, three monocular trials were performed in each eye alternatively, and the responses for each eye were subsequently averaged. Results: Six out of the seven concussed adolescents showed response enhancement of about 20% (IQR 11-33%). Enhancement was noted in the steady state diameter with a mean of 24% (median 18%), minimum pupil diameter mean of 17% (median 11%) and maximum constriction velocity mean of 28% (median 33%) following concussion, which decreased during the recovery process (days to weeks post-injury) to pre-injury or below initial pre-injury baseline measurements. Pupillary responsivity was found to be significantly enhanced after concussion compared to baseline measurements, waning over time. Maximum constriction velocity better highlighted the enhancement compared to the baseline pupil diameter. Conclusions/Significance: Pupil responsivity was found to be significantly enhanced after concussion compared to baseline measurements which waned over time during recovery. Assessment of dynamic PLR responses has potential utility as an objective biomarker to aid in concussion diagnosis on the sidelines or in the office, allowing physicians to quantify function (and dysfunction) of the autonomic nervous system under parasympathetic and sympathetic control after concussion.

scholarly journals Pupillary Light Reflex in Children with ADHD

2019 ◽  
Vol 19 (1) ◽  
pp. 30-37
Author(s):  
A Hamrakova ◽  
I Ondrejka ◽  
N Sekaninova ◽  
L Peregrim ◽  
I Tonhajzerova
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Mental Disorders ◽  
Dynamic Balance ◽  
Pupillary Light Reflex ◽  
Light Reflex ◽  
Autonomic Nervous ◽  
Pupillary Light ◽  
Medical Diagnostic ◽  
Invasive Method

Abstract Attention deficit/hyperactivity disorder (ADHD) is one of the most frequently seen mental disorders in children with an increasing risk for other mental disorders. ADHD represents a primary biological dysfunction of the central nervous system, such as dysregulation of frontal-subcortical-cerebellar catecholaminergic circuits and imbalances in the dopaminergic system. However, autonomic nervous system, comprised of two primary branches - sympathetic and parasympathetic nervous systems that are normally in dynamic balance, plays an essential role in the regulation of body functions. Although it is generally assumed that the autonomic regulation is impaired during ADHD the information related to this dysregulation is limited. One of the options to observe changes of autonomic balance in ADHD is pupillary light reflex (PLR). Pupillometric evaluation can be used for the assessment of functioning of both autonomic nervous system branches and certain parameters of pupil responsivity can be helpful as a tool for medical diagnostic and treatment. In conclusion, these findings suggest the pupillometry as a non-invasive method that can indicate abnormalities in the complex central autonomic network regulating PLR.

scholarly journals Central Autonomic Regulation Assessed by Pupillary Light Reflex is Impaired in Children With Attention Deficit Hyperactivity Disorder

2021 ◽  
pp. S513-S521
Author(s):  
A HAMRAKOVA ◽  
I ONDREJKA ◽  
N SEKANINOVA ◽  
L BONA OLEXOVA ◽  
Z VISNOVCOVA ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Pupil Diameter ◽  
Light Stimulus ◽  
Autonomic Regulation ◽  
Pupillary Light Reflex ◽  
Light Reflex ◽  
Hyperactivity Disorder ◽  
Non Invasive ◽  
Pupillary Light

It is assumed that the Attention Deficit Hyperactivity Disorder is associated with the central autonomic dysregulation, however, the studies are rare. Analysis of pupillary light reflex represents a non-invasive tool to provide information related to the central autonomic regulation; thus, we aimed to evaluate potential disturbances in the central autonomic integrity using pupillary light reflex examination in Attention Deficit Hyperactivity Disorder. We have examined 20 children with Attention Deficit Hyperactivity Disorder (10 boys, 13.0±2.3 years) and 20 age/gender-matched healthy subjects. Pupillary light reflex was examined at rest for both eyes using Pupillometer PLR-2000 (NeurOptics, USA). Evaluated parameters were: diameter of the pupil before the application of light stimulus and after illumination at the peak of the constriction, the percentual change of the pupil diameter during constriction, average constriction velocity, maximum constriction velocity and average dilation velocity. We found significantly lower percentual change of the pupil diameter during constriction for both eyes in Attention Deficit Hyperactivity Disorder group compared to controls (right eye: -25.81±1.23 % vs. -30.32±1.31 %, p<0.05, left eye: -25.44±1.65 % vs. -30.35±0.98 %, p˂0.05). The average constriction velocity and maximum constriction velocity were significantly shortened in left eye in Attention Deficit Hyperactivity Disorder group compared to controls (p˂0.05). Our findings revealed altered pupillary light reflex indicating abnormal centrally-mediated autonomic regulation characterized by parasympathetic underactivity associated with relative sympathetic predominance in children suffering from Attention Deficit Hyperactivity Disorder.

scholarly journals The use Of Pupillary Light Reflex in Concussed Athletes

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0027
Author(s):  
Olivia E. Podolak ◽  
Kristy B. Arbogast ◽  
Joshi B. Nabin ◽  
Kenneth Ciuffreda ◽  
Matthew Grady ◽  
...  
Keyword(s):  
Light Stimulus ◽  
Symptom Burden ◽  
Pupillary Light Reflex ◽  
Adolescent Athletes ◽  
Post Injury ◽  
Light Reflex ◽  
Clinical Assessments ◽  
Pupillary Light ◽  
Pupillary Responses ◽  
Clinical Measures

Background: Despite advancements, concussion diagnosis remains reliant on subjective symptom report and clinical assessments. Visual deficits and autonomic dysfunction have been described following concussion. Testing of the pupillary light reflex (PLR) is a simple, portable, non-invasive, and objective means of quantifying pupillary function. Purpose: The aim of this study was to objectively evaluate pupillary responses to a light stimulus in concussed adolescent athletes and to determine whether clinical assessments correlated with PLR responses after a diagnosed concussion when compared to pre-injury responses. Methods: In this prospective cohort study, PLR and clinical measures [PCSI and/or SCAT symptom scales, near point of convergence (NPC) and accommodation amplitude (AA) of both eyes] were assessed in 93 (45 female), non-concussed adolescent athletes (ages 14-18) during their pre-season. PLR was obtained in response to a brief white light stimulus using a hand-held pupillometer. During each assessment, three monocular trials were performed in each eye alternatively, with subsequent averaged responses for each eye. Seven athletes (ages 14-17) sustained a concussion and had post-injury assessments of PLR and clinical measures completed longitudinally through recovery. Results: All seven concussed athletes completed PLR and clinical assessments at least once post-injury (mean initial day of evaluation = 6 days post injury). Six out of the seven concussed athletes demonstrated an increase in steady state diameter of 24% (median 18%), minimum pupil diameter of 17% (median 11%) and a maximum constriction velocity of 28% (median 33%) following concussion which decreased over the course of recovery, returning to pre-injury or below pre-injury measurements. Six of seven of the concussed athletes completed NPC and AA assessments at both pre-season and post-injury timepoints. In contrast to the PLR findings, both NPC and AA measures were normal at post-injury assessments. Reported symptom scores improved throughout recovery, correlating with PLR response recovery, with both returning to pre-injury measurements. Conclusion: Pupil responsivity was found to be significantly enhanced after concussion compared to pre-injury measurements, waning over time during recovery, following a similar trajectory as symptom burden. NPC and AA, which have autonomic contributions and are clinical measures, were normal pre- and post-injury and did not differentiate the concussed state from the uninjured state in our series. Our preliminary results demonstrate that dynamic PLR responses may detect acute autonomic deficits that are not evident via clinical assessments. Further investigation of its potential utility as sensitive and objective biomarker in concussion diagnosis, management and sports clearance is warranted.

scholarly journals Pupillary Light Reflex is Altered in Adolescent Depression

2017 ◽  
pp. S277-S284 ◽  
Author(s):  
A. MESTANIKOVA ◽  
I. ONDREJKA ◽  
M. MESTANIK ◽  
D. CESNEKOVA ◽  
Z. VISNOVCOVA ◽  
...  
Keyword(s):  
Nervous System ◽  
Major Depression ◽  
Parasympathetic Nervous System ◽  
Dynamic Balance ◽  
Pupillary Light Reflex ◽  
Control Group ◽  
Light Reflex ◽  
Pupillary Light ◽  
Adolescent Patients ◽  
Depressive Group

Major depressive disorder is associated with abnormal autonomic regulation which could be noninvasively studied using pupillometry. However, the studies in adolescent patients are rare. Therefore, we aimed to study the pupillary light reflex (PLR), which could provide novel important information about dynamic balance between sympathetic and parasympathetic nervous system in adolescent patients suffering from major depression. We have examined 25 depressive adolescent girls (age 15.2±0.3 year) prior to pharmacotherapy and 25 age/gender-matched healthy subjects. PLR parameters were measured separately for both eyes after 5 min of rest using Pupillometer PLR-2000 (NeurOptics, USA). The constriction percentual change for the left eye was significantly lower in depressive group compared to control group (-24.12±0.87 % vs. –28.04±0.96%, p˂0.01). Furthermore, average constriction velocity and maximum constriction velocity for the left eye were significantly lower in depressive group compared to control group (p˂0.05, p˂0.01, respectively). In contrast, no significant between-groups differences were found for the right eye. Concluding, this study revealed altered PLR for left eye indicating a deficient parasympathetic activity already in adolescent major depression. Additionally, the differences between left and right eye could be related to functional lateralization of autonomic control in the central nervous system.

Abstract TMP97: Autonomic Nervous System Dysfunction Correlates With Increased Blood Pressure Variability After Acute Ischemic, But Not Hemorrhagic, Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Adam H de Havenon ◽  
Melissa Cortez ◽  
Cecilia Peterson ◽  
Fa Tuuhetaufa ◽  
Nils Petersen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Blood Pressure Variability ◽  
Hemorrhagic Stroke ◽  
Light Stimulus ◽  
Pupillary Response ◽  
Autonomic Nervous System Dysfunction ◽  
Autonomic Nervous ◽  
The Mean

Background: Elevated blood pressure variability (BPV) in the days after acute stroke onset is associated with worse outcome. However, the mechanism of increased BPV remains unknown, but may be due to dysfunction of the autonomic nervous system, which can be measured by pupil response to a light stimulus. Methods: This is a retrospective study of 109 patients in a neurocritical care unit: 45 with acute ischemic stroke (AIS), 44 with intracerebral hemorrhage (ICH), and 20 with subarachnoid hemorrhage (SAH). The primary outcome is BPV, measured as standard deviation of SBP (SD), using all blood pressures from admission to 72 hours later. The primary predictors are pupillary light reflexes (PLR) from the same period, measured with a bedside pupilometer, the NPi-200. We used linear regression to evaluate the association between PLRs and BPV, and adjusted for patient age and gender. Results: The mean (SD) age was 60.7 (16.4) and 58.7% were male. The mean (SD) number of blood pressure and PLR measurements were 30.0 (9.0) and 10.4 (7.3). We found that parasympathetically mediated PLR measures were associated with BPV in AIS patients (Table 1), but no consistent pattern emerged in ICH or SAH patients (all p>0.05). The relationships between BPV and PLR for AIS patients were linear in nature (Figure 1), and were consistent with parasympathetic hypofunction in patients with the greatest BPV. Conclusions: Elevated BPV is associated with parasympathetic hypofunction, as measured by pupillary response to light, after acute ischemic, but not hemorrhagic, stroke. Further research is needed to better understand this relationship as it may represent a therapeutic target for BPV reduction.

Nonlinearity and fractality in the variability of cardiac period in the lizard, Gallotia galloti: effects of autonomic blockade

2008 ◽  
Vol 295 (4) ◽  
pp. R1282-R1289
Author(s):  
Luis De Vera ◽  
Alejandro Santana ◽  
Julian J. Gonzalez
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Chaotic Behavior ◽  
Autonomic Nervous ◽  
Fractal Properties ◽  
Adrenergic Activity ◽  
Autonomic Blockade ◽  
Cardiac Period ◽  
Over Time ◽  
Gallotia Galloti

Both nonlinear and fractal properties of beat-to-beat R-R interval variability signal (RRV) of freely moving lizards ( Gallotia galloti) were studied in baseline and under autonomic nervous system blockade. Nonlinear techniques allowed us to study the complexity, chaotic behavior, nonlinearity, stationarity, and regularity over time of RRV. Scaling behavior of RRV was studied by means of fractal techniques. The autonomic nervous system blockers used were atropine, propranolol, prazosin, and yohimbine. The nature of RRV was linear in baseline and under β-, α1- and α2-adrenoceptor blockades. Atropine changed the linear nature of RRV to nonlinear and increased its stationarity, regularity and fractality. Propranolol increased the complexity and chaotic behavior, and decreased the stationarity, regularity, and fractality of RRV. Both prazosin and yohimbine did not change any of the nonlinear and fractal properties of RRV. It is suggested that 1) the use of both nonlinear and fractal analysis is an appropriate approach for studying cardiac period variability in reptiles; 2) the cholinergic activity, which seems to make the α1-, α2- and β-adrenergic activity interaction unnecessary, determines the linear behavior in basal RRV; 3) fractality, as well as both RRV regularity and stationarity over time, may result from the balance between cholinergic and β-adrenergic activities opposing actions; 4) β-adrenergic activity may buffer both the complexity and chaotic behavior of RRV, and 5) neither the α1- nor the α2-adrenergic activity seem to be involved in the mediation of either nonlinear or fractal components of RRV.

Consistency and Test-Retest Reliability of Spontaneous Autonomic Nervous System Activity and Eye Movements

1965 ◽  
Vol 20 (3_suppl) ◽  
pp. 1225-1228 ◽  
Author(s):  
Frank E. Hustmyer ◽  
J. Alan Burdick
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Eye Movements ◽  
Autonomic Nervous System Activity ◽  
Retest Reliability ◽  
System Activity ◽  
Autonomic Nervous ◽  
Nervous System Activity ◽  
Test Retest Reliability ◽  
Over Time

Spontaneous autonomic nervous system (ANS) activity (GSR) was recorded during rest, and frequency of horizontal eye movements was recorded during the viewing of two different dot patterns by 14 Ss. The same tasks were repeated after a 2- to 4-mo. period. ANS activity during rest was found to be quite consistent over time ( rho = .75, p < .01) as were eye movements. The within-session rho between eye movements on the patterns was .30 (N.S.) for the first session and .76 ( p < .01) for the second session. The rhos of eye movements obtained 2 to 4 mo. apart were .58 ( p < .05) for a 6-dot stimulus and .77 ( p < .01) for a 1-dot stimulus. When eye movements for the 2 conditions were combined, rho was .78 ( p < .01) between the sessions separated by 2 to 4 mo.

scholarly journals A method to quantify autonomic nervous system function in healthy, able-bodied individuals

2020 ◽  
Author(s):  
Shubham Debnath ◽  
Todd J. Levy ◽  
Mayer Bellehsen ◽  
Rebecca M. Schwartz ◽  
Douglas P. Barnaby ◽  
...  
Keyword(s):  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Pupil Diameter ◽  
Electrodermal Activity ◽  
Cold Pressor Test ◽  
Healthy Population ◽  
Individual Response ◽  
Autonomic Nervous ◽  
Organ Systems

AbstractThe autonomic nervous system (ANS), which maintains physiological homeostasis in various organ systems via parasympathetic and sympathetic branches, is altered in common diffuse and focal conditions. Sensitive, quantitative biomarkers could detect changes in ANS function, first here in healthy participants and eventually in patients displaying dysautonomia. This framework combines controlled autonomic testing with feature extraction from physiological responses. Twenty-one individuals were assessed in two morning and two afternoon sessions over two weeks. Each session included five standard clinical tests probing autonomic function: squat test, cold pressor test, diving reflex test, deep breathing, and Valsalva maneuver. Noninvasive sensors captured continuous electrocardiography, blood pressure, breathing, electrodermal activity, and pupil diameter. Heart rate, heart rate variability, mean arterial pressure, electrodermal activity, and pupil diameter responses to the perturbations were extracted, and averages across participants were computed. A template matching algorithm calculated scaling and stretching features that optimally fit the average to an individual response. These features were grouped based on test and modality to derive sympathetic and parasympathetic indices for this healthy population. A significant positive correlation (p = 0.000377) was found between sympathetic amplitude response and body mass index. Additionally, longer duration and larger amplitude sympathetic and longer duration parasympathetic responses occurred in afternoon testing sessions; larger amplitude parasympathetic responses occurred in morning sessions. These results demonstrate the robustness and sensitivity of an algorithmic approach to extract multimodal responses from standard tests. This novel method of quantifying ANS function can be used for early diagnosis, measurement of disease progression, or treatment evaluation.

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