Testing Visual Function by Assessment of the Optomotor Reflex in Glaucoma.

Optomotor response/reflex (OMR) is a fast and efficient first-in-line visual screening method, especially for rodents. It has the potential to evaluate both the scotopic and photopic visions of nonrestrained animals through tracking head movement, providing a quantitative estimate of visual functions. In restrained animals, optokinetic response (OKR), compensatory eye movements for visual shifts in the surroundings, is utilized. Both OMR and OKR capitalize on an individual's innate reflex to stabilize images for the purpose of capturing clear vision. The two reflexes have similar reliability when evaluating stimulus luminance, contrast, spatial frequency, and velocity. They have emerged as powerful tools to evaluate the efficacy of pharmacological treatments and phenotypes of subjects undergoing study. With OMR and OKR accurately assessing visual acuity (VA) as well as contrast sensitivity (CS), the gold standards for measuring clinical vision, they provide reliable and easily accessible results that further eye and brain research. These methods of sight evaluation have been used in multiple animal models, particularly mice and zebrafish. Through OMR assays, these animal models have been utilized to investigate retinal degenerative diseases, helping researchers differentiate between worsening stages. Alongside tests such as optical coherence tomography (OCT), OMR provides confirmation of visual status, where increased OMR function often correlates with improved visual status. OMR has continued to be used outside of glaucoma in various retinal diseases, such as retinitis pigmentosa (RP), diabetic retinopathy, and age-related macular degeneration.In this chapter, we will introduce the concept and application of visual stimulus-induced head or eye reflex movement in different animal species and experimental models of eye diseases, such as glaucoma and other neurodegenerative disorders, and in patients with glaucoma.

Brain-body physiology: Local, reflex, and central communication.

Behavior is tightly synchronized with bodily physiology. Internal needs from the body drive behavior selection, while optimal behavior performance requires a coordinated physiological response. Internal state is dynamically represented by the nervous system to influence mood and emotion, and body-brain signals also direct responses to external sensory cues, enabling the organism to adapt and pursue its goals within an ever-changing environment. In this review, we examine the anatomy and function of the brain-body connection, manifested across local, reflex, and central regulation levels. We explore these hierarchical loops in the context of the immune system, specifically through the lens of immunoception, and discuss the impact of its dysregulation on human health.

Consolidating roles of neuroimmune reflexes: specificity of afferent, central, and efferent signals in homeostatic immune networks.

Neural reflexes occupy a central role in physiological homeostasis. The vagus nerve is a major conduit for transmitting afferent and efferent signals in homeostatic reflex arcs between the body and the brain. Recent advances in neuroscience, immunology, and physiology have revealed important vagus nerve mechanisms in suppressing inflammation and treating rheumatoid arthritis and other autoimmune conditions. Numerous clinical trials indicate that there is significant benefit to vagus nerve stimulation therapy. Although many questions are still unanswered, it will be important, even necessary, to pursue answers that will be useful in guiding interventions to modulate immunological and physiological homeostasis.

Effects of Early Life Scarcity-Adversity on Maturational Milestones in Male and Female Rats.

Although many studies have shown a long-term negative impact of early life adversity (ELA) in rodents, literature regarding its effects on maturational milestones in rats is scarce. Available evidence suggests that ELA interferes with normal growth and development in rodents and that effects may be sex-dependent even at an early age. In accordance, we hypothesized that early life scarcity-adversity would impair physical and reflex development in male and female rats. To test this, we used an early life resource scarcity paradigm based on reducing home cage bedding during postnatal days (PND) 2-9 and assessed physical landmarks by measuring weight gain, incisor presence, fur development, and eye opening. We also evaluated the impact of early life scarcity-adversity on developmental reflexes by measuring surface righting and grasp reflexes, negative geotaxis, cliff avoidance, bar holding, and auditory startle. Early life scarcity-adversity resulted in earlier complete lower incisor presence in males (PND 6), impaired surface righting (PND 6) and grasp reflexes (PND 8) in both sexes, and impaired cliff avoidance responses in females (PND 12). These results extend previous research examining the effects of ELA on developing male and female rodents by showing that it negatively impacts a subset of physical landmarks and developmental reflexes in a sex-dependent manner.

Intraoperative bulbocavernosus reflex monitoring for predicting postoperative voiding dysfunction in patients with distal intraspinal tumors.

OBJECTIVE: To investigate the predictive value of intraoperative bulbocavernosus reflex (BCR) monitoring for voiding dysfunction post-operatively in patients with distal intraspinal tumors and to determine an appropriate timing for postoperative follow-up assessment. METHODS: Patients with distal intraspinal tumors who underwent surgery with BCR monitoring were collected. Patients were classified into BCR absent and present groups according to the monitoring responses at the end of surgery. Voiding function was evaluated at 1 week, 2 months, 4 months, and 6 months after surgery. RESULTS: A total of 52 patients were included. There were 30 (57.7 %) males and the mean age was (48.6 ± 17.2) years. Forty-nine (94.2 %) patients were adult. BCR was preserved in 50 (96.2 %) patients and completely disappeared in 2 cases at the end of the surgery. The sensitivity of intraoperative BCR loss for worsened voiding were 20.0 %, 33.3 %, 66.7 %, and 100.0 % at 1 week, 2 months, 4 months, and 6 months post-operatively respectively. The specificity was all 100.0 % at the four follow-ups. Preoperative voiding difficulty was more common in patients suffering from worsened voiding than those maintained at 1 week post-operatively (P < 0.05). CONCLUSIONS: Intraoperative BCR monitoring is a reliable technique to predict the postoperative voiding dysfunction in patients with distal intraspinal tumors. Preservation of the BCR is a robust indication for favorable postoperative urinary function as time goes on and 6-month post-operatively may be an optimal timing for functional assessment with high sensitivity and specificity. Preoperative voiding symptoms may be a risk factor for voiding difficulty at early stage after surgery.

Developmental Changes in Locomotion and Sensorimotor Reflexes Following Spinal Cord Transection.

The developmental trajectory of weight-bearing locomotion and sensorimotor reflexes following a spinal cord injury, as well as the mechanisms for plasticity, remain unclear. In rats, the second postnatal week is a critical period for the development and recovery of spinal sensorimotor function. The purpose of the present study was to characterize developmental changes during this time frame to provide a basis for potential interventions and future research. Rats underwent a complete low-thoracic (T8-T10) spinal cord transection surgery, or sham procedure, on postnatal day (P)1. Spontaneous locomotion and sensorimotor reflexes (surface righting, hindlimb placing, and crossed-extensor reflex) were tested on P7, P14, or P21. Results show that spinal-transected and sham rats exhibited the same amount of spontaneous locomotion, but the degree of relative weight bearing on the hindlimbs was different between groups and changed over time. Reflex findings showed that throughout the neonatal period, the isolated lumbar spinal cord can respond to sensory input and execute coordinated motor output following spinal cord transection. These insights contribute to understanding the developmental trajectory of spinal cord function after injury and provide a foundation for interventions to enhance recovery outcomes.

Effects of acepromazine, xylazine and propofol on spinal reflexes in healthy dogs.

BACKGROUND: In the neurological examination, it is crucial to identify the possible location of the lesion in order to determine the appropriate treatment process. In aggressive animals, chemical restraint may be necessary due to their non-cooperative behaviour. However, sedatives may distort the results of examinations. Therefore, a drug should be found that has minimal impact on the examination results. OBJECTIVES: To investigate the effects of acepromazine, xylazine, and propofol on spinal reflexes in healthy dogs. METHODS: In a randomized, blinded study, ten native adult mixed-breed dogs were participated in three groups with a 1-week washout period between each group. Before performing each step, the spinal reflexes were evaluated. Then, in the first group, acepromazine (0.05 mg/kg, IM), in the second group, xylazine (1 mg/kg, IM), and in the third group, propofol (3 mg/kg, IV for initial bolus and 0.1 mg/kg/min for maintenance) were injected for sedation. The spinal reflexes were reevaluated at maximum sedation and at 15, 30, and 45 min thereafter. RESULTS: Acepromazine increased the patellar reflex and decreased the panniculus reflex. Xylazine increased the cranial tibial reflex and decreased the panniculus reflex, while propofol decreased the withdrawal, and extensor carpi radialis reflexes, and suppressed the palpebral and gag reflexes. CONCLUSIONS: The drugs used in the present study did not have a significant impact on the most important reflexes evaluated in neurological examinations. Among the drugs, acepromazine has the least effects compared to other drugs, making it a suitable choice for sedation.

(Don't) take my breath away: Rare epithelial cells in our airways initiate reflexes to guard against harmful stimuli.

Rare epithelial cells in our airways initiate reflexes to guard against harmful stimuli.

Vglut2-based glutamatergic signaling in central noradrenergic neurons is dispensable for normal breathing and chemosensory reflexes.

Central noradrenergic (NA) neurons are key constituents of the respiratory homeostatic network. NA dysfunction is implicated in several developmental respiratory disorders including Congenital Central Hyperventilation Syndrome (CCHS), Sudden Infant Death Syndrome (SIDS), and Rett Syndrome. The current unchallenged paradigm in the field, supported by multiple studies, is that glutamate co-transmission in subsets of central NA neurons plays a role in breathing control. If true, NA-glutamate co-transmission may also be mechanistically important in respiratory disorders. However, the requirement of NA-derived glutamate in breathing has not been directly tested and the extent of glutamate co-transmission in the central NA system remains uncharacterized. Therefore, we fully characterized the cumulative fate maps and acute adult expression patterns of all three vesicular glutamate transporters (Slc17a7 (Vglut1), Slc17a6 (Vglut2), and Slc17a8 (Vglut3)) in NA neurons, identifying a novel, dynamic expression pattern for Vglut2 and an undescribed co-expression domain for Vglut3 in the NA system. In contrast to our initial hypothesis that NA-derived glutamate is required to breathing, our functional studies showed that loss of Vglut2 throughout the NA system failed to alter breathing or metabolism under room air, hypercapnia, or hypoxia in unrestrained and unanesthetized mice. These data demonstrate that Vglut2-based glutamatergic signaling within the central NA system is not required for normal baseline breathing and hypercapnic, hypoxic chemosensory reflexes. These outcomes challenge the current understanding of central NA neurons in the control of breathing and suggests that glutamate may not be a critical target to understand NA neuron dysfunction in respiratory diseases.

Changes in primitive reflexes in older adults and their relationship to mental health indices: An experimental investigation.

The reemergence of primitive reflexes (PRs) in older age is related to cognitive impairment. Currently, there are no means to prevent or slow their reappearance, but research evidence exists for their control in children. Therefore, this experiment investigated whether a 16-week special sensorimotor exercise program could benefit older adults and whether the intervention-induced changes (if any) may be associated with various indices of mental health. Of 115 adults over 60, 95 completed the study (mean age = 76.37 ± SD = 7.04 years, 22 % men). The experimental group (n = 38) showed an almost threefold decline in PRs compared to controls. In contrast, the control group (n = 57) exhibited a nearly threefold increase in PRs compared to the intervention group. Cognitive function increased in the experimental but not in the control group. Changes in PRs over the 16-week intervention were positively related to negative mental health indices (hopelessness and perceived stress) and negatively related to well-being. These findings suggest that the here-presented mild sensorimotor exercises could affect older adults' reemerging PRs and that changes in PRs are associated with mental health benefits. These results may open new research avenues toward preventing cognitive and psychological decline in older adults.

Descending motor drive does not interact with muscle metaboreflex for ventilation regulation during rhythmic exercise in healthy humans.

The muscle metaboreflex effect on pulmonary ventilation (V̇E) regulation is more apparent during rhythmic exercise than rest, possibly because this reflex interacts with other mechanisms regulating V̇E during voluntary contractions, such as central command. Therefore, we tested whether one part of central command, the descending component of motor execution (i.e., descending motor drive), and the muscle metaboreflex interact synergistically to regulate V̇E. Thirteen healthy adults (9 men) completed four experiments in random order under isocapnia. The muscle metaboreflex was activated by rhythmic handgrip exercise at 60% maximal voluntary contraction (MVC) force with the dominant hand. Then, the muscle metaboreflex remained active during a 4-min recovery period via postexercise circulatory occlusion (PECO), or it was inactivated, maintaining free blood flow to the dominant upper limb. During the last 2 min of the handgrip exercise recovery, participants either performed rhythmic voluntary plantar flexion with the dominant leg at 30% MVC torque to generate descending motor drive or the dominant leg's calf muscles were involuntarily activated by electrical stimulation at a similar torque level (i.e., without descending motor drive). V̇E increased to a similar level during handgrip exercise in all conditions (≈22 L/min, P = 0.364). PECO maintained V̇E elevated above recovery with free blood flow (≈17 L/min vs. ≈13 L/min, P = 0.009). However, voluntary and involuntary plantar flexion with or without PECO evoked similar V̇E responses (Δ ≈ 4 L/min, P = 0.311). Therefore, an interaction between descending motor drive and muscle metaboreflex is not ubiquitous for V̇E regulation during rhythmic exercise.NEW & NOTEWORTHY Voluntary (i.e., with descending motor drive) and involuntary (i.e., no descending motor drive) plantar flexion elicited similar ventilatory responses when postexercise circulatory occlusion was or was not used in an upper limb. These results indicate that the descending motor drive component of the central command and the muscle metaboreflex do not interact to regulate pulmonary ventilation during rhythmic exercise, which suggests that a supposed interaction between central command-muscle metaboreflex is more complex than previously thought.

Sex-based differences in the blood pressure responses to muscle metaboreflex activation are consistent between limb and respiratory muscle.

The purpose of this study was to compare sex-based differences in the mean arterial blood pressure (MAP) response to limb and inspiratory metaboreflex activation, during relative and absolute workloads. Healthy males (n = 9) and females (n = 8) completed pulmonary function testing, forearm volume and circumference measurements, and bouts of limb and inspiratory muscle exercise. The exercises performed included bouts of rhythmic handgrip exercise (RHG) and inspiratory pressure threshold loading (PTL) to task failure, performed in a randomized order and separated by 30 minutes of rest. Participants performed both RHG and PTL at predetermined relative (R) and absolute (A) workloads, while cardiopulmonary measurements were recorded continuously. A time-dependent rise in MAP was observed in all participants, regardless of sex, muscle, or workload (P < 0.001). MAP was greater in males than females during all exercise bouts regardless of muscle group or workload (P < 0.001). The change in MAP from baseline was also greater in males (R-RHG: Δ31 ± 12 mmHg; R-PTL: Δ31 ± 9; A-RHG: Δ35 ± 6; and A-PTL: Δ30 ± 7) than females (R-RHG: Δ21 ± 7 mmHg; R-PTL: Δ13 ± 7; A-RHG: Δ21 ± 7; and A-PTL: Δ14 ± 3) (P < 0.001). Results from this study show that when the forearm and diaphragm perform the same relative or absolute work, the blood pressure response is statistically similar, and both responses are greater in males than females. The findings from the present study suggest that the sex-based difference in the response to metaboreflex activation is similar between the limb and respiratory musculature.NEW & NOTEWORTHY With rhythmic handgrip exercise and inspiratory pressure threshold loading there was a time-dependent rise in the blood pressure that was significantly lower in females than males. The blunted blood pressure response in females was present whether handgrip or inspiratory workload was relative or absolute. An attenuated cardiovascular response to high levels of limb or respiratory muscle work may have implications for whole body exercise in health and disease.

The Influence of Cough Reflex Testing on Patient Management.

PURPOSE: Cough reflex testing (CRT) is an adjunct to the clinical swallowing evaluation (CSE), providing information on patients' risk of silent aspiration. CRT has been shown to influence diet recommendations, but in previous work, the many varied patient characteristics are not controlled. Therefore, the specific role of CRT results in these decisions remains unclear as this relationship has not been directly assessed. METHOD: An online survey was sent to speech language therapists working in dysphagia. Two patient cases were presented that differed only by the presence of risk factors for the development of aspiration pneumonia. For each patient case, there were three assessment scenarios: CSE information only, CSE information with a "pass" CRT result, and CSE information with a "fail" CRT result. Clinicians outlined their patient management plans for each of the six scenarios. RESULTS: Ninety-seven data sets were used in the final analysis. A "fail" result was found to lead to the most restrictive patient management. Decisions made when provided with only CSE information were very similar to decisions made for a CSE with a "pass" result. Aspiration pneumonia risk factors were shown to influence decision making, with the low-risk patient more likely to be recommended a less restrictive diet. CONCLUSIONS: When information was available regarding silent aspiration risk, clinicians factored the results into their decision making. However, in the absence of a CRT result, airway sensation was assumed to be intact in the absence of information. This finding warrants further investigation given the impact this assumption may have on a patient's pulmonary health.

Apraisal of the diagnostic value of the gag reflex in patients with neurogenic oropharyngeal dysphagia / Evaluación del valor clínico del reflejo nauseoso en la disfagia orofaríngea neurogénica.

Introduction: The gag reflex is a protection mechanism that prevents food and unwanted agents from entering the lower airways. It is usually part of the physical examination of swallowing to detect oropharyngeal dysphagia, but it is a potentially ambiguous sign. Objective: To evaluate the diagnostic value of the gag reflex in patients with neurogenic oropharyngeal dysphagia and adults without it. Materials and methods: We conducted an analytical observational study in patients with neurogenic oropharyngeal dysphagia (cases) and patients without dysphagia (controls). We evaluated the absence or presence of the reflex bilaterally, by direct visualization, and adjusted it according to sex, age, and other interaction variables. Results: We included 86 patients with neurogenic oropharyngeal dysphagia and 80 control subjects. The gag reflex on swallowing physical examination showed a positive relationship with the patients (right side: OR = 3.97; 95 % CI: 2.01-7.84; left side: OR = 4.84; 95 % CI: 2.41-9.72), but a negative association with the control group. In both groups, neither sex, nor age, nor other interaction variables modified the gag reflex. Conclusions: The gag reflex absence or presence does not confirm or exclude the existence of oropharyngeal dysphagia due to neurological and neuromuscular causes. Therefore, health professionals must not rely on this reflex. Clinicians must go beyond a simple reflex revision, even in neurological patients where it is supposed to be absent.

Introducción. El reflejo nauseoso es un mecanismo de protección que impide que alimentos y agentes no deseados penetren en la vía aérea inferior. Usualmente, hace parte del examen físico de la deglución para detectar la disfagia orofaríngea, pero es un signo potencialmente ambiguo. Objetivo. Evaluar el valor diagnóstico del reflejo nauseoso en pacientes con disfagia orofaríngea neurogénica y en pacientes sin ella. Materiales y métodos. Se trata de un estudio observacional, analítico, en pacientes con disfagia orofaríngea neurogénica (casos) y en personas sin disfagia (controles), en el cual se evaluó por visualización directa la ausencia o la presencia del reflejo nauseoso de forma bilateral. Este resultado se ajustó por sexo, edad y otras variables de interacción. Resultados. Se evaluaron 86 pacientes con disfagia orofaríngea neurogénica y 80 personas sin ella. En el examen físico de la deglución, la presencia del reflejo mostró una relación positiva con los pacientes (lado derecho: OR = 3,97; IC95%: 2,01-7,84; lado izquierdo: OR = 4,84; IC95%: 2,41-9,72), pero una asociación negativa con los controles. En ambos grupos, ni el sexo ni la edad, ni otras variables de interacción modificaron el reflejo nauseoso. Conclusiones. La ausencia o la presencia del reflejo nauseoso no confirma ni excluye la existencia de una disfagia orofaríngea por causas neurológicas o neuromusculares; por lo tanto, no es recomendable que los profesionales de la salud se fíen del resultado de este reflejo. Los médicos tratantes deben ir más allá de una simple revisión del reflejo nauseoso, incluso en pacientes neurológicos en quienes se supone que debería estar ausente.

Functional involvement of the sternohyoid muscle during breathing and swallowing in rats.

The sternohyoid muscle depresses the hyoid bone, but it is unclear whether the muscle contributes to respiratory and swallowing mechanisms. This study aimed to clarify whether the sternohyoid muscle participates in the respiration and swallowing reflex and how the activity is modulated in two conditions: with airway stenosis and with a fixed sternohyoid muscle length. Electromyographic activity in the sternohyoid, digastric, thyrohyoid, and diaphragm muscles was recorded in anesthetized rats. The sternohyoid muscle activity was observed in the inspiratory phase and during swallowing, and was well coordinated with digastric and thyrohyoid muscle activity. With airway stenosis, the respiratory activity per respiratory cycle was facilitated in all assessed muscles but the facilitation of activity per second occurred only in the digastric, thyrohyoid, and sternohyoid muscles. With airway stenosis, the swallowing activity was facilitated only in the digastric muscle but not in the thyrohyoid and sternohyoid muscles. Swallowing activity was not observed in the sternohyoid muscle in the condition with the sternohyoid muscle length fixed, although increased inspiratory activity remained. The current results suggest that 1) the sternohyoid muscle is slightly activated in the inspiratory phase, 2) the effect of airway stenosis on respiratory function may differ between the upper airway muscles and diaphragm, and 3) swallowing activity in the sternohyoid muscle is not dominantly controlled by the swallowing central pattern generator but instead occurs as a myotatic reflex.NEW & NOTEWORTHY We found that the sternohyoid muscle was activated in the inspiratory phase. However, increased airway resistance had different effects on the extrathoracic muscles than on the diaphragm. The swallowing activity of the sternohyoid disappeared when the muscle length was fixed. These findings suggest that the sternohyoid muscle may be activated not by the swallowing central pattern generator but as a myotatic reflex.

Acute effects of local vibration inducing tonic vibration reflex or illusion of movement on maximal wrist force production.

Local vibration (LV) mainly stimulates primary afferents (Ia) and can induce a tonic vibration reflex (TVR) and an illusion of movement. This study aimed to evaluate the effect of these two phenomena on maximal voluntary isometric contraction (MVIC) capacity. LV (80 Hz) was applied to the wrist flexor muscles in two randomized experiments for 6 min. LV conditions were adjusted to promote either TVR (visual focus on the vibrated wrist) or ILLUSION [hand hidden, visual focus on electromyographic activity of the flexor carpi radialis muscle (FCR)]. Mechanical and electromyographic (EMG) responses of the FCR and extensor carpi radialis muscles were recorded during MVIC in flexion and extension and during electrically evoked contractions at supramaximal intensity. Measurements were performed before (10 min and just before) and after (0 and 30 min) LV protocol. An increase in FCR EMG was observed during LV in the TVR condition (+340%) compared with the illusion condition (P = 0.003). In contrast, the movement illusion was greater in the ILLUSION condition (assessed through subjective scales) (P = 0.004). MVIC was reduced in flexion only after the TVR condition ([Formula: see text], all P < 0.034). Moreover, the decrease in force was correlated with the amount of TVR recorded on the FCR muscle (r = -0.64, P = 0.005). Although potentiated doublets of each muscle did not evolve differently between conditions, a decrease was observed between the first and the last measure. In conclusion, when conducting research to assess maximal strength, it is necessary to have better control and reporting of the phenomena induced during LV.NEW & NOTEWORTHY The maximal force production of the vibrated muscle is reduced after 6 min of LV only in TVR condition. Furthermore, the amount of TVR is negatively correlated with this force decrease. When measuring the effects of LV on maximal force production, it is important to control and report any phenomena induced during vibration, such as TVR or movement illusion, which can be achieved by recording EMG activity of vibrated muscle and quantifying illusion.

Virtual muscles and reflex control generates human-like ankle torques during gait perturbations.

A biologically-inspired actuation system, including muscles, spinal reflexes, and vestibular feedback, may be capable of achieving more natural gait mechanics in powered prostheses or exoskeletons. In this study, we developed a Virtual Muscle Reflex (VMR) system to control ankle torque and tuned it using data from human responses to anteroposterior mechanical perturbations at three walking speeds. The system consists of three Hill-Type muscles, simulated in real time, and uses feedback from ground reaction force and from stretch sensors on the virtual muscle fibers. Controller gains, muscle properties, and reflex/vestibular time delays were optimized using Covariance Matrix Adaptation (CMA) to minimize the difference between the VMR torque output and the torque measured from the experiment. We repeated the procedure using a conventional finite-state impedance controller. For both controllers, the coefficient of determination (R2) and root-mean-square error (RMSE) was calculated as a function of time within the gait cycle. The VMR had lower RMSE than the impedance controller in 70%, and in 60% of the trials, the R2 of the VMR controller was higher than for the impedance controller. We concluded that the VMR system can better reproduce the human responses to perturbations than the impedance controller.

Contralateral cutaneous reflex modulation during gait in individuals with and without chronic ankle instability.

INTRODUCTION: Chronic ankle instability (CAI), a common seqeula to ankle injury is characterized by a variety of sensorimotor deficits extending beyond the previously injured limb. Cutaneous reflexes have been identified as a potential contributor to these functional limitations with recent studies identifying alterations in reflex patterns following sural nerve stimulation among those with CAI. To date, no studies have measured cutaneous reflexes of the unaffected limb in this population, therefore, the objective of this study was to measure contralateral cutaneous reflexes during gait in individuals with unilateral CAI and healthy controls. METHODS: Muscle activity of 6 lower limb muscles was measured in nineteen participants while receiving random, non-noxious sural nerve stimulations during a walking task. RESULTS: Control reflex patterns were generally well-aligned with previous literature while CAI patterns varied from controls in several muscles throughout the gait cycle. Namely, a lack of lateral gastrocnemius facilitation during late stance and medial gastrocnemius inhibition at midstance. Additionally, a lack of significant BF facilitation throughout contralateral swing was noted. These results indicate reflex alterations extend beyond the affected limb in those with unilateral CAI indicating changes at the spinal level following lateral ankle sprains (LAS). Considering the symptom variability in CAI, the lack of significant reflexes exhibited by the CAI group may be due to increased variability in motor output between subjects or between stimulation trials. CONCLUSIONS: These findings highlight the importance of identifying reflex alterations arising from LAS and subsequently treating these limitations through rehabilitation targeting systemic neural pathways rather than local deficits.