Optokinetic Stimulation Research Articles

What do we know about eye movements in Alzheimer's disease? The past 37 years and future directions.

What do we know about eye movements in Alzheimer's disease? The past 37 years and future directions.

Impact of optokinetic stimulation on mental arithmetic.

Solving arithmetic problems has been shown to induce shifts of spatial attention, subtraction problems orienting attention to the left side, and addition problems to the right side of space. At the neurofunctional level, the activations elicited by the solving of arithmetical problems resemble those elicited by horizontal eye movements. Whether overt orientation of attention (i.e., eye movements) can be linked to the solving procedure is, however, still under debate. In the present study, we used optokinetic stimulation (OKS) to trigger automatic eye movements to orient participants' overt attention to the right or to the left of their visual field while they were solving addition or subtraction problems. The results show that, in comparison to leftward OKS and a control condition, rightward OKS facilitates the solving of addition problems that necessitate a carrying procedure. Subtraction solving was unaffected by leftward or rightward OKS. These results converge with previous findings to show that attentional shifts are functionally related to mental arithmetic processing.

Vestibular and Oculomotor Assessments May Increase Accuracy of Subacute Concussion Assessment.

In this study, we collected and analyzed preliminary data for the internal consistency of a new condensed model to assess vestibular and oculomotor impairments following a concussion. We also examined this model's ability to discriminate concussed athletes from healthy controls. Each participant was tested in a concussion assessment protocol that consisted of the Neurocom's Sensory Organization Test (SOT), Balance Error Scoring System exam, and a series of 8 vestibular and oculomotor assessments. Of these 10 assessments, only the SOT, near point convergence, and the signs and symptoms (S/S) scores collected following optokinetic stimulation, the horizontal eye saccades test, and the gaze stabilization test were significantly correlated with health status, and were used in further analyses. Multivariate logistic regression for binary outcomes was employed and these beta weights were used to calculate the area under the receiver operating characteristic curve ( area under the curve). The best model supported by our findings suggest that an exam consisting of the 4 SOT sensory ratios, near point convergence, and the optokinetic stimulation signs and symptoms score are sensitive in discriminating concussed athletes from healthy controls (accuracy=98.6%, AUC=0.983). However, an even more parsimonious model consisting of only the optokinetic stimulation and gaze stabilization test S/S scores and near point convergence was found to be a sensitive model for discriminating concussed athletes from healthy controls (accuracy=94.4%, AUC=0.951) without the need for expensive equipment. Although more investigation is needed, these findings will be helpful to health professionals potentially providing them with a sensitive and specific battery of simple vestibular and oculomotor assessments for concussion management.

Postural Instability in Children with ADHD Is Improved by Methylphenidate.

HIGHLIGHTS Both spatial and temporal analyses of the Center of Pressure demonstrate that children with ADHD have poorer postural control than typically developing sex-, age-, and IQ-matched children.Poor sensory integration in postural control could partially explained the deficits in postural stability in children with ADHD.MPH treatment improves postural performance in both spatial and temporal domains in children with ADHD.MPH improves postural control specifically when visual and proprioceptive inputs are misleading.Such improvement could be due to MPH effects on neurons, facilitating cerebellar processing of postural control.The aim of this study was to examine postural control in children with ADHD and explore the effect of methylphenidate (MPH), using spatial and temporal analyses of the center of pressure (CoP). Thirty-eight children with ADHD (mean age 9.82 ± 0.37 years) and 38 sex- age- and IQ-matched children with typically development were examined. Postural stability was evaluated using the Multitest Equilibre machine (Framiral®) at inclusion and after 1 month of MPH in children with ADHD. Postural stability was assessed by recording under several conditions: with eyes open and fixed on a target, with eyes closed and with vision perturbed by optokinetic stimulation, on stable and unstable platforms. At inclusion, we observed poor spatial and temporal postural stability in children with ADHD. The spectral power index was higher in children with ADHD than in controls. Canceling time was shorter at low and medium frequencies of oscillation and longer at higher frequencies in children with ADHD. After 1 month of MPH, the surface area and mean velocity of the CoP decreased significantly under the most complex conditions (unstable platform in the absence of proprioceptive and visual inputs). The spectral power index decreased significantly after MPH while the canceling time did not change. Poor postural control in children with ADHD supports the hypothesis of cerebellar dysfunction in this disorder. Postural control could be improved by a more efficient processing of sensory inputs (a high-level process), as suggested by the decrease in spectral power index after MPH without changes in the canceling time (a low-level process).

The Effect of Optokinetic Stimulation on Perceptual and Postural Symptoms in Visual Vestibular Mismatch Patients.

BackgroundVestibular patients occasionally report aggravation or triggering of their symptoms by visual stimuli, which is called visual vestibular mismatch (VVM). These patients therefore experience discomfort, disorientation, dizziness and postural unsteadiness.ObjectiveFirstly, we aimed to get a better insight in the underlying mechanism of VVM by examining perceptual and postural symptoms. Secondly, we wanted to investigate whether roll-motion is a necessary trait to evoke these symptoms or whether a complex but stationary visual pattern equally provokes them.MethodsNine VVM patients and healthy matched control group were examined by exposing both groups to a stationary stimulus as well as an optokinetic stimulus rotating around the naso-occipital axis for a prolonged period of time. Subjective visual vertical (SVV) measurements, posturography and relevant questionnaires were assessed.ResultsNo significant differences between both groups were found for SVV measurements. Patients always swayed more and reported more symptoms than healthy controls. Prolonged exposure to roll-motion caused in patients and controls an increase in postural sway and symptoms. However, only VVM patients reported significantly more symptoms after prolonged exposure to the optokinetic stimulus compared to scores after exposure to a stationary stimulus.ConclusionsVVM patients differ from healthy controls in postural and subjective symptoms and motion is a crucial factor in provoking these symptoms. A possible explanation could be a central visual-vestibular integration deficit, which has implications for diagnostics and clinical rehabilitation purposes. Future research should focus on the underlying central mechanism of VVM and the effectiveness of optokinetic stimulation in resolving it.

Voluntary eye movements direct attention on the mental number space.

Growing evidence suggests that orienting visual attention in space can influence the processing of numerical magnitude, with leftward orienting speeding up the processing of small numbers relative to larger ones and the converse for rightward orienting. The manipulation of eye movements is a convenient way to direct visuospatial attention, but several aspects of the complex relationship between eye movements, attention orienting and number processing remain unexplored. In a previous study, we observed that inducing involuntary, reflexive eye movements by means of optokinetic stimulation affected number processing only when numerical magnitude was task relevant (i.e., during magnitude comparison, but not during parity judgment; Ranzini et al., in J Cogn Psychol 27, 459-470, (2015). Here, we investigated whether processing of task-irrelevant numerical magnitude can be modulated by voluntary eye movements, and whether the type of eye movements (smooth pursuit vs. saccades) would influence this interaction. Participants tracked with their gaze a dot while listening to a digit. The numerical task was to indicate whether the digit was odd or even through non-spatial, verbal responses. The dot could move leftward or rightward either continuously, allowing tracking by smooth pursuit eye movements, or in discrete steps across a series of adjacent locations, triggering a sequence of saccades. Both smooth pursuit and saccadic eye movements similarly affected number processing and modulated response times for large numbers as a function of direction of motion. These findings suggest that voluntary eye movements redirect attention in mental number space and highlight that eye movements should play a key factor in the investigation of number-space interactions.

Utilization of oculomotor therapies in the treatment of vertigo originating from mild traumatic brain injury

Event Abstract Back to Event Utilization of oculomotor therapies in the treatment of vertigo originating from mild traumatic brain injury Beau Arrieta1 and Susan E. Esposito1* 1 Life University, United States Background: A 25-year-old caucasian female chiropractor presented with mild traumatic brain injury following an automobile accident. Subsequent to being struck, her vehicle was thrown into a right multi-rotational spin. The patient complained of extreme vertigo, fatigue, and difficulty falling asleep which collectively precluded her ability to work. Magnetic resonance imaging and computerized tomography scans were unremarkable. Methods: A neurological exam revealed a right accommodation spasm that inhibited normal ocular divergence. It was ascertained that she was able to generate appropriate reflexive responses to optokinetic stimuli up to a maximum distance of 2.5 feet. Notably, optokinetic stimulation at a distance beyond 2.5 feet, administered in any direction, elicited a vertiginous response. Optokinetic stimulation at a distance exceeding 2.5 feet produced a reduction in both fast- and slow-phase eye movements with a positive correlation between distance-to-stimulus and level of diminution. Treatment consisted of weekly 2-hour sessions, for 4 weeks. Numerous oculomotor therapies were utilized including: (1) passively activated times-one viewing vertical gaze stability exercises tracking a distancing target; (2) horizontal pursuits tracking a distancing sinusoidal target; and (3) rightward optokinetic stimulation with an in-phase target coupled with active head rotation in-phase with the optokinetic target. Results: Post-treatment evaluation revealed restoration of normal ocular divergence and reinstatement of appropriate optokinetic reflexes at all distances. Optokinetic stimulation no longer induced vertiginous responses at any distance or in any direction. Additionally, the patient reported that her fatigue and sleeping complications had subsided, and she was able to return to work. Conclusion: The positive outcome of this case demonstrates that the utilization of oculomotor therapies can be efficacious in the treatment of vertigo due to mild traumatic brain injury. We recommend further investigation into the use of oculomotor therapies in the treatment of vertigo originating from mild traumatic brain injury. Keywords: Traumatic Brain Injury, Chiropractic, oculomotor therapy, Vertigo, Fatigue Conference: International Symposium on Clinical Neuroscience: Clinical Neuroscience for Optimization of Human Function, Orlando, United States, 7 Oct - 9 Oct, 2016. Presentation Type: Poster Presentation Topic: Abstracts ISCN 2016 Citation: Arrieta B and Esposito SE (2016). Utilization of oculomotor therapies in the treatment of vertigo originating from mild traumatic brain injury. Front. Neurol. Conference Abstract: International Symposium on Clinical Neuroscience: Clinical Neuroscience for Optimization of Human Function. doi: 10.3389/conf.fneur.2016.59.00005 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Aug 2016; Published Online: 07 Sep 2016. * Correspondence: Dr. Susan E Esposito, Life University, Marietta, Ga, 30144, United States, susanesposito@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Beau Arrieta Susan E Esposito Google Beau Arrieta Susan E Esposito Google Scholar Beau Arrieta Susan E Esposito PubMed Beau Arrieta Susan E Esposito Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Multimodal neurorehabilitation for treatment of mild traumatic brain injury

Multimodal neurorehabilitation for treatment of mild traumatic brain injury

Vertigo Perception and Quality of Life in Patients after Surgical Treatment of Vestibular Schwannoma with Pretreatment Prehabituation by Chemical Vestibular Ablation.

Surgical removal of vestibular schwannoma causes acute vestibular symptoms, including postoperative vertigo and oscillopsia due to nystagmus. In general, the dominant symptom postoperatively is vertigo. Preoperative chemical vestibular ablation can reduce vestibular symptoms postoperatively. We used 1.0 mL of 40 mg/mL nonbuffered gentamicin in three intratympanic installations over 2 days, 2 months preoperatively in 10 patients. Reduction of vestibular function was measured by the head impulse test and the caloric test. Reduction of vestibular function was found in all gentamicin patient groups. After gentamicin vestibular ablation, patients underwent home vestibular exercising for two months. The control group consisted of 10 patients who underwent only home vestibular training two months preoperatively. Postoperative rates of recovery and vertigo in both groups were evaluated with the Glasgow Benefit Inventory (GBI), the Glasgow Health Status Inventory (GHSI), and the Dizziness Handicap Inventory questionnaires, as well as survey of visual symptoms by specific questionnaire developed by us. There were no statistically significant differences between both groups with regard to the results of questionnaires. Patients who received preoperative gentamicin were more resilient to optokinetic and optic flow stimulation (p < 0.05). This trial is registered with clinical study registration number NCT02963896.

Functional neurological treatment approach for chronic dizziness in an adult female patient.

Functional neurological treatment approach for chronic dizziness in an adult female patient.

Improvement of post-concussion symptoms of migraines, vestibular dysfunction and cognitive impairments with integrated neuro-rehabilitative therapies

Event Abstract Back to Event Improvement of post-concussion symptoms of migraines, vestibular dysfunction and cognitive impairments with integrated neuro-rehabilitative therapies Elizabeth McNally1, Austin Jones2 and Linda Mullin Elkins2* 1 Portland Chiropractic Neurology, United States 2 Life University; College of Chiropractic, United States Background: A 33-year-old female presented to a chiropractic functional neurology clinic with complaints of extreme fatigue, dizziness, short-term memory loss, migraines, nausea, motion sickness, asthenopia, photophobia and hyperacusis. These symptoms began immediately following a concussion six months previous and remain unresolved. Methods: The patient had a stooped upper body posture with significant anterior translation of the head and shoulders. Computerized Dynamic Posturography (CDP) revealed instability on a hard and perturbed surface with eyes closed. Videonystagmography (VNG) testing was performed. VNG revealed a fast fail on left pupillary response and right hippus, bilateral accommodation spasm and divergence insufficiency. Optokinetic (OPK) stimulation showed minimal to no response in leftward and upward directions. Saccades were hypometric for upward and leftward motion with the head in perceived neutral and then in right yaw. Pursuits showed a breakdown in all fields with disconjugacy due to right oculomotor weakness in all cardinal directions. Utilizing the Movement Disorder Society Unified Parkinson’s Disease Rating Scale, finger tapping yielded a grade 3 for freezing on the left, and a grade 2 for hesitations on the right. Treatment consisted of spinal manipulative therapy, proprioceptive neurofacilitated retraining, myofascial release, intersegmental traction, postural exercises, electrical muscle stimulation and cold laser therapy at a frequency of five times per week for 3 weeks. Results: The application of this unique combination of patient specific therapies yielded resolution of most of the patient’s symptoms. She reported more energy and improved memory. Her dizziness, nausea and motion sickness significantly improved. She was no longer sensitive to light and sound. VNG retesting showed that vertical and left gaze holding were normal but a mild hippus remained. Accommodation, divergence and pupillary responses all markedly improved. Pursuits and saccades were accurate in all cardinal planes. Improvements in all directions of OPK stimulation except downward were seen. Finger tapping improved bilaterally. Repeat CDP demonstrated improved stability with global postural improvements. Conclusion: This case shows significant improvements in chronic persistent symptoms associated with concussion through an integrated neuro-rehabilitation regimen as described. The authors suggest further investigation into brain-based approaches for patient treatments with mild traumatic brain injuries. Keywords: Post-Concussion Syndrome, Traumatic Brain Injury, Chiropractic manipulation, Fatigue, Migraine Conference: International Symposium on Clinical Neuroscience: Clinical Neuroscience for Optimization of Human Function, Orlando, United States, 7 Oct - 9 Oct, 2016. Presentation Type: Poster Presentation Topic: Abstracts ISCN 2016 Citation: McNally E, Jones A and Mullin Elkins L (2016). Improvement of post-concussion symptoms of migraines, vestibular dysfunction and cognitive impairments with integrated neuro-rehabilitative therapies. Front. Neurol. Conference Abstract: International Symposium on Clinical Neuroscience: Clinical Neuroscience for Optimization of Human Function. doi: 10.3389/conf.fneur.2016.59.00015 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Aug 2016; Published Online: 07 Sep 2016. * Correspondence: Dr. Linda Mullin Elkins, Life University; College of Chiropractic, Marietta, GA, United States, mullin@life.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Elizabeth McNally Austin Jones Linda Mullin Elkins Google Elizabeth McNally Austin Jones Linda Mullin Elkins Google Scholar Elizabeth McNally Austin Jones Linda Mullin Elkins PubMed Elizabeth McNally Austin Jones Linda Mullin Elkins Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Resolution of fatigue, hyperacusis and acquired dyslexia using integrated therapies

Event Abstract Back to Event Resolution of fatigue, hyperacusis and acquired dyslexia using integrated therapies Matthew M. Antonucci1, Katherine Habanek2 and Linda Mullin Elkins2* 1 Plasticity Brain Centers, United States 2 Life University; College of Chiropractic, United States Background: A 28-year-old male presented with complaints of fatigue, hyperacusis and acquired dyslexia. Significant history included a past diagnosed of post-concussive syndrome The patient stated that he would view the treatment as successful if the symptoms were reduced by 40%. Methods: Neurocognitive testing using a concussion management system (C3Logix) was used to reliably and objectively assess the patient’s physical findings and delivered. This testing revealed a symptom severity score of 62/162. Computerized dynamic posturography (CDP) was used to quantify and differentiate between possible sensory, motor and central adaptive impairments to balance control. This subject’s stability score was 84.4% with eyes open on a solid surface and 78.9% with eyes open on a perturbed surface. Functional tests revealed a dynamic right hypertropia, failed convergence on the right, left ptosis with left corectasia. Optokinetic stimulation revealed a right beating post pursuit nystagmus which was confirmed by videonystagmography (VNG). The VNG also revealed right square wave jerks in right gaze with increased blinking and hippus in upward gaze. Further examination revealed bilateral decrease in arm swing during gait analysis, decrease in left palate tone, slow capillary refill on the left hand and decreased right biceps tendon reflex. Dysmetria was also present on a finger-to nose-test with the left arm less accurate than the right. Therapeutic intervention consisting of nerve stimulation, vision therapy, vestibular rehabilitation, cognitive exercises, chiropractic adjustments and multi-axis rotational therapy were administered 3-5 times per day for 5 consecutive days. Results: After the 5 day treatment plan, neurocognitive testing was repeated and showed a 69% decrease in the symptom severity score. The patient had a significant decrease in all subjective complaints and showed significant improvement in all positive exam findings. Conclusions: A novel patient centered treatment program improved objective and subjective measures. More research is needed into the use of integrated therapies in the treatment of post-concussion syndrome. Keywords: Chiropractic, Post-Concussion Syndrome, spinal manipulation, Fatigue, Hyperacusis Conference: International Symposium on Clinical Neuroscience: Clinical Neuroscience for Optimization of Human Function, Orlando, United States, 7 Oct - 9 Oct, 2016. Presentation Type: Poster Presentation Topic: Abstracts ISCN 2016 Citation: Antonucci MM, Habanek K and Mullin Elkins L (2016). Resolution of fatigue, hyperacusis and acquired dyslexia using integrated therapies. Front. Neurol. Conference Abstract: International Symposium on Clinical Neuroscience: Clinical Neuroscience for Optimization of Human Function. doi: 10.3389/conf.fneur.2016.59.00020 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Aug 2016; Published Online: 07 Sep 2016. * Correspondence: Dr. Linda Mullin Elkins, Life University; College of Chiropractic, Marietta, GA, 30060, United States, mullin@life.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Matthew M Antonucci Katherine Habanek Linda Mullin Elkins Google Matthew M Antonucci Katherine Habanek Linda Mullin Elkins Google Scholar Matthew M Antonucci Katherine Habanek Linda Mullin Elkins PubMed Matthew M Antonucci Katherine Habanek Linda Mullin Elkins Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Visual Spatial Attention Training Improve Spatial Attention and Motor Control for Unilateral Neglect Patients.

To compare the effect of visual spatial training on the spatial attention to that on motor control and to correlate the improvement of spatial attention to motor control progress after visual spatial training in subjects with unilateral spatial neglect (USN). 9 cases with USN after right cerebral stroke were randomly divided into Conventional treatment group + visual spatial attention and Conventional treatment group. The Conventional treatment group + visual spatial attention received conventional rehabilitation therapy (physical and occupational therapy) and visual spatial attention training (optokinetic stimulation and right half-field eye patching). The Conventional treatment group was only treated with conventional rehabilitation training (physical and occupational therapy). All patients were assessed by behavioral inattention test (BIT), Fugl-Meyer Assessment of motor function (FMA), equilibrium coordination test (ECT) and non-equilibrium coordination test (NCT) before and after 4 weeks treatment. Total scores in both groups (without visual spatial attention/with visual spatial attention) improved significantly (BIT: P=0.021/P=0.000, d=1.667/d=2.116, power=0.69/power=0.98, 95%CI[-0.8839,45.88]/95%CI=[16.96,92.64]; FMA: P=0.002/P=0.000, d=2.521/d=2.700, power=0.93/power=0.98, 95%CI[5.707,30.79]/95%CI=[16.06,53.94]; ECT: P=0.002/ P=0.000, d=2.031/d=1.354, power=0.90/power=0.17, 95%CI[3.380,42.61]/95%CI=[-1.478,39.08]; NCT: P=0.013/P=0.000, d=1.124/d=1.822, power=0.41/power=0.56, 95%CI[-7.980,37.48]/95%CI=[4.798,43.60],) after treatment. Among the 2 groups, the group with visual spatial attention significantly improved in BIT (P=0.003, d=3.103, power=1, 95%CI[15.68,48.92]), FMA of upper extremity (P=0.006, d=2.771, power=1, 95%CI[5.061,20.14]) and NCT (P=0.010, d=2.214, power=0.81-0.90, 95%CI[3.018,15.88]). Correlative analysis shows that the change of BIT scores is positively correlated to the change of FMA total score (r=0.77, P<;0.01), FMA of upper extremity (r=0.81, P<0.01), NCT (r=0.78, P<0.01). Four weeks visual spatial training could improve spatial attention as well as motor control functions in hemineglect patients. The improvement of motor function is positively correlated to the progresses of visual spatial functions after visual spatial attention training.

Balance Rehabilitation Unit (BRUTM) posturography in Menière's disease

AbstractPosturography has been used in the evaluation of patients with vestibular disorders. AimTo evaluate balance control with the Balance Rehabilitation Unit (BRUTM) posturography in patients with Menière's disease. Study designProspective case-control. Material and Method30 patients diagnosed with Menière's disease and a control group consisting of 40 healthy matching individuals in relation to age and gender, were submitted to a balance function evaluation by means of a Balance Rehabilitation Unit (BRUTM) posturography. ResultsComparing patients with Menière's disease and the control group, we found significant differences between the values of the sway speed in the static force plate, down optokinetic stimulation (p=0.038) and horizontal visual vestibular interaction (p=0.049); and of the ellipse area in the static force plate, eyes closed (p=0.001); left optokinetic stimulation (p=0.007); down optokinetic stimulation (p=0.003); horizontal visual vestibular interaction (p=0.003); and vertical visual vestibular interaction (p=0.028). ConclusionThe postural control assessment with the Balance Rehabilitation Unit (BRUTM) posturography enables the identification of sway speed and ellipse area abnormalities in patients with Menière's disease.

Balance in Parkinson's disease patients changing the visual input

AbstractThe description of the postural responses in Parkinson's disease patients when visual information changes from a stable to a moving visual field analyzing the impact on balance in these patients. Methods (Clinical)Limits of Stability, Body center of pressure and balance functional reserve were measured by means of the force platform in 24 Parkinson's patients in stages 1 and 2 of the Boher classification and 19 volunteers as a control group. Both groups were stimulated with 1-Static visual field and 2-horizontal optokinetic stimulation using a virtual reality system. Postural responses were analyzed using the inverted pendulum as mathematical model. ResultsWhile the control group didn't show significant differences on the postural control between the two sensory conditions (COP p=0.0017, BFR p=0.0025), Parkinson's patients presented significant differences in the area of the center of pressure and the balance functional reserve values between static visual field and optokinetic stimulation. (COP p=0.0017, BFR p=0.0025). ConclusionsThe results support the hypothesis about the influence of the changes in the visual information in triggering balance control disorders in Parkinson's patients. It is discussed the interest of these fact in the assessment and the rehabilitation programs of this disease.

Novel Use of Optokinetic Chart Stimulation to Restore Muscle Strength and Function in a Bed Bound Traumatic Brain Injury Patient that was in a Vegetative State of Unconsciousness: A Case Study

Introduction: Patients with severe traumatic brain injury are known to have poor outcomes. The prognosis is even worse if they remain vegetative or minimally conscious for months. The objective of this case report is to highlight the novel use of optokinetic chart stimulation to improve muscle strength and functional mobility in a patient who was in a vegetative state of unconsciousness for months after sustaining a severe traumatic brain injury and C7 spinal fracture. The patient could not open their eyes and breathed through a tracheostomy tube.

Effect of Developmental Binocular Vision Abnormalities on Visual Vertigo Symptoms and Treatment Outcome

Customized vestibular rehabilitation incorporating optokinetic (OK) stimulation improves visual vertigo (VV) symptoms; however, the degree of improvement varies among individuals. Binocular vision abnormalities (misalignment of ocular axis, ie, strabismus) may be a potential risk factor. This study aimed to investigate the influence of binocular vision abnormalities on VV symptoms and treatment outcome. Sixty subjects with refractory peripheral vestibular symptoms underwent an orthoptic assessment after being recruited for participation in an 8-week customized program incorporating OK training via a full-field visual environment rotator or video display, supervised or unsupervised. Treatment response was assessed at baseline and at 8 weeks with dynamic posturography, Functional Gait Assessment (FGA), and questionnaires for symptoms, symptom triggers, and psychological state. As no significant effect of OK training type was noted for any variables, data were combined and new groups identified on the basis of the absence or presence of a binocular vision abnormality. A total of 34 among 60 subjects consented to the orthoptic assessment, of whom 8 of the 34 had binocular vision abnormalities and 30 of the 34 subjects completed both the binocular function assessment and vestibular rehabilitation program. No significant between-group differences were noted at baseline. The only significant between-group difference was observed for pre-/post-VV symptom change (P = 0.01), with significant improvements noted only for the group without binocular vision abnormalities (P < 0.0005). Common vestibular symptoms, posturography, and the FGA improved significantly for both groups (P < 0.05). Binocular vision abnormalities may affect VV symptom improvement. These findings may have important implications for the management of subjects with refractory vestibular symptoms.Video Abstract available for insights from the authors regarding clinical implication of the study findings (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A115).

Optokinetic circular vection: a test of visual-vestibular conflict models of vection nascensy.

The propensity to experience circular vection (the illusory perception of self-turning evoked by a rotating scene, CV) as reflected by its onset latency exhibits considerable interindividual variation. Models of CV nascensy have linked this delay to the time it takes the visual-vestibular conflict to disappear. One line of these "conflict models" (Zacharias and Young in Exp Brain Res 41:159-171, 1981) predicts that, across individuals, CV latency (CVL) correlates positively with the vestibular time constant (TC) and negatively with the vestibular motion detection threshold (vTHR). A second type of models (Mergner et al. in Arch Ital Biol 138:139-166, 2000) predicts only an increase in CVL with TC. We here examine which of these predictions can be experimentally substantiated. Also, we ask whether the relative weight W O of the optokinetic contribution to the perception of real self-turning could also be a factor influencing CVL. We conducted 5 experiments in 29 subjects measuring: (1) CVL, (2) the TCs of velocity perception and of accompanying nystagmus during rotation in darkness and (3) likewise for displacement perception, (4) vTHR, and (5) W O as revealed by discordant visual-vestibular stimulation. CVL correlated with the nystagmus TC recorded during velocity estimation but with none of the other vestibular TCs nor with vTHR. Confirming earlier findings, CVL shortened with rising scene velocity. Finally, CVL correlated inversely with W O: the larger an individual's optokinetic weight, the shorter was his CVL. Taken together, our data favour the second type of models which invoke an antagonism between CV inhibition by the optokinetic-vestibular conflict and disinhibition by optokinetic stimulation. Idiosyncratic factors appear to strongly modulate the balance between inhibition and disinhibition, thus increasing CVL variability and obscuring the expected relation between CVL and TC.

Subjective Visual Vertical and Adolescent Idiopathic Scoliosis (AIS)

The AIS is pathology with multifactorial origin. It affects between 1 – 3% of the population aged 10 – 16 years. Many authors suggest orthostatic postural control disorders in AIS. The orthostatic postural control is the ability to organize the standing posture on the earth-vertical. The longitudinal body axis, the trunk and the spinal axis are oriented in an internal representation of the gravitational vertical. Our hypothesis is that AIS is the consequence of a re-organization of orthostatic postural control, on an erroneous internal representation of earth-vertical. Our objective is to show a disturbance of the sense of verticality in the AIS, by measuring the Subjective Visual Vertical (SVV) in AIS, particularly in dynamic visual condition. Prospective study: a group of adolescents with AIS versus a control group of non-scoliotic adolescents. The test is a measure of the SVV (Synapsis), standing posture, in static and dynamic visual conditions (visual disturbance by optokinetic stimulation 40°/sec). Six measures are evaluated. Norms for static condition–2.5° to +2.5°, and for dynamic condition–4 to +4°. Preliminary results on 35 scoliotic adolescents (Group S: 31 girls, 14.2 ± 1.74 years, angle: 38.4 ± 15.7°), versus 5 non-scoliotic adolescents (Group C: 5 girls, 14.9 ± 1.14 years). Group S: static VVS = 1.59 ± 1.45°; dynamic VVS = 4.7 ± 8.27°. 57.1% with a least 1 pathological value, 28.5% with a least 2 pathological values, particularly in dynamic visual condition (clockwise rotation with right tilt of the VVS, average 12.39°). Group C: static VVS = 0.72 ± 0.5°; dynamic VVS = 2.17 ± 1.5°. No subject control with pathological value. This preliminary study shows a disturbance in the vertical evaluation in the AIS. One possible explanation is a disturbance of the sense of verticality by impaired multisensory central integration. The authors are grateful to the Harps Association's members, for their helpful comments.

Effects of microvascular decompression surgery on posture control: A case report in an elderly patient

We report the case of an 84-year-old woman with neurovascular conflict of the left cochleovestibular nerve. Prior to surgery, the patient complained of positional vertigo and dizziness for the past two years, and marked instability. Hearing loss and tinnitus were reported on the left side. The aim of this study was to investigate the effects of microvascular decompression of the cochleovestibular nerve on posture control. Evaluation of cochleovestibular function and posture control was performed before and after surgery. Postural performance was analyzed in static and dynamic conditions, with and without vision, and with optokinetic stimulation. Perception of the static visual vertical (SVV) was recorded in darkness. Positional vertigo and tinnitus disappeared immediately after the decompression. The SVV remained unchanged one week after the surgery. Speech intelligibility of the left ear was improved (30 dB), and the vestibular deficit on this side was also significantly reduced (54% versus 18%). However, the more spectacular result was the effect on postural control. This elderly patient improved her postural balance in both static and dynamic conditions, and became able to maintain her equilibrium in the more challenging dynamic conditions, with and without vision, as early as one week after the surgery, a postural performance that she had been unable to do preoperatively. This work is the first to show that the postural deficits resulting from neurovascular conflict of the cochleovestibular nerve are strongly improved after microvascular decompression.