For Patients

Info for Patients

Organization Links

  1. VeDA: The Vestibular Disorders Association’s mission is to inform, support and advocate for the vestibular community.
  2. U.S. Centers for Disease Control and Prevention (CDC): Brain Injury & Concussions — Signs and Symptoms.
  3. Brain Injury Association of America (BIAA) – A nationwide network of chartered state affiliates providing direct support and advocacy for individuals living with brain injury, their friends and family, professionals and the general public.
  4. U.S. Department of Veterans Affairs VA’s Polytrauma System of Care (PSC) is an integrated network of specialized rehabilitation programs dedicated to serving Veterans and Service Members with both combat and civilian related Traumatic Brain Injury (TBI) and polytrauma.

Understanding the Science of Eye Tracking. For the advanced reader, explore NKI’s website for a curated repository to learn more about the science and discoveries in clinical eye tracking and non-invasive neuro-functional diagnostic testing. Find a wide assortment of peer-reviewed, published, scientific research paperswhite papers & case studies and news from NKI and others in industry.

Over 30 years of collaborations with researchers and clinicians has made NKI instrumental in the early and ongoing development of clinical measurement tools associated with important vestibular, neuro-functional and ophthalmic discoveries. These collaborations have meant that NKI has had to put particular emphasis on the precision engineering and science within its I-Portal technologies. Such a long history of clinical leadership has resulted in 26 patents, and put NKI in the unique position of successfully moving cutting edge bench discoveries to bed-side, or into daily clinical settings.

Published Research

NKI Collaborative Research and Studies Involving I-Portal® Systems

Below is a mere a sampling of the of the numerous published papers involving NKI and I-Portal technology. Explore the sections further below sorted by topic area for a more comprehensive bibliography.

  • Oculomotor, Vestibular, and Reaction Time Tests in Mild Traumatic Brain Injury.
    September 21, 2016
    Recent research on mTBI is revealing that crHIT is probably one of tests to include when doing a limited battery to assess concussion. This paper by Dr. Carey Balaban, University of Pittsburgh, and others is compelling on many fronts.  Link
  • The use of Oculomotor, Vestibular and Reaction Time Test to assess mild Traumatic Brain Injury (mTBI) over time
    April 12, 2017Published in Laryngoscope Investigative Otolaryngology journal, is the following article by Dr. Michael Hoffer, University of Miami, Miller School of Medicine, et al. The results describe an objective and effective second generation testing algorithm for diagnosing and following the prognosis of mTBI/concussion during the sub-acute time period up to two weeks post-event. The authors conclude the testing paradigm will allow investigators to institute better treatments and provide more accurate return to activity advice. Six measures from 5 tests were found to classify the control and mTBI during Session 1 with a true positive rate (sensitivity) of 85% and true negative rate (specificity) of 97%.  Link
  • The Horizontal Computerized Rotational Impulse Test
    July 8, 2016

    Dr. Joseph Furman, Department of Otolaryngology, University of Pittsburgh reviews a study that concludes that the horizontal crHIT overcomes many of the limitations of manual head impulse testing and provides a reliable laboratory-based measure.  Link
  • Rotational chair testing: “To rotate, or not to rotate, that is the real question”
    November 1, 2015Paul Radomskij discusses the benefits, application and clinical utility of passive rotation tests in identifying vestibular disorders with respect to vestibular testing. Link
  • Auditory, Vestibular and Cognitive Effects due to Repeated Blast Exposure on the Warfighter
    July, 2012
    Principal investigator LTC Kristen L. Casto, Ph.D. studied and reported on multi-modal effects of repeated blast exposure using I-Portal® systems in this body of research prepared for the U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland. View PDF

Other Published Research

  • Check back often for new content in this sampling and in the curated sections by subject that follow.

For Professionals

· Vestibular, NKI pre-I-Portal®

 “The Early Days” – Research done on NKI-designed systems, but not I-Portal technology

  1. Dai, M; Raphan, T; Kozlovskaya, I and Cohen, B: Modulation of vergence by off-vertical yaw axis rotation in the monkey normal characteristics and effects of space flight; Experimental Brain Research, Volume 111, Issue 1, pp 21-29, September 1996. Link
  2. Gordon, Carlos R.; Shupak, Avi; Spitzer, Orna; Doweck, Ilana and Melamed, Yehuda: Nonspecific vertigo with normal otoneurological examination. The role of vestibular laboratory tests, Laryngol Otol 1996 Dec;110(12):1133-1137.
  3. Angeli, Simon I.,MD, Marianne Abouyared, MD, Hillary Snapp, AuD, Daniel Jethanamest, MD: Utricular Dysfunction in Refractory Benign Paroxysmal Positional Vertigo, Otolaryngol Head Neck Surg. 2014 Apr 25;151(2):321-327.
  4. Clément, Gilles, Wood, Scott J.; Eye movements and motion perception during off-vertical axis rotation after spaceflight; Journal of Vestibular Research, vol. 23, no. 1, pp. 13-22, 2013.
  5. McNeely, Marie E.; Earhart, Gammon M.: Lack of Short-Term Effectiveness of Rotating Treadmill Training on Turning in People with Mild-to-Moderate Parkinson’s Disease and Healthy Older Adults: A Randomized, Controlled Study; Parkinson’s Disease; Volume 2012 (2012), Article ID 623985, 8 pages; Link
  6. Helling, Kai, Hausmann, Stefan; Clarke, Andrew and Scherer, Hans: Experimentally Induced Motion Sickness in Fish: Possible Role of the Otolith Organs, Acta Oto-Laryngologica Volume 123, Issue 4, 2003, pages 488-492. Link
  7. Hong, Minna and Earhart, Gammon M.: Rotating treadmill training reduces freezing in Parkinson disease: preliminary observations; Parkinsonism Relat Disord. 2008 May; 14(4): 359–363.
  8. Jacob J. Bloomberg, | Lauren A. Merkle, | Susan R. Barry, | William P. Huebner, | Helen S. Cohen, | S. Alyssa Mueller, | James Fordice: Effects of adaptation of vestibulo-ocular reflex function on manual target localization; Journal of Vestibular Research, vol. 10, no. 2, pp. 75-86, 2000;
  9. Gordon, C.R., A. Kuritzky, I. Doweck, O. Spitzer, A. Shupak, and R. Hering, Vestibulo-Ocular Reflex in Migraine Patients: The Effect of Sodium Valproate; Headache: The Journal of Head and Face Pain; Volume 33, Issue 3, pages 129–132, March, 1993;
  10. Guzy, Lawrence ; Albery, William ; Bowden, David Effects of Tactile and Audio Cues on Reducing Vestibular Illusions; Apr 2004-Jun 2006; Link
  11. Parmentier JC, The physics of labyrinthine motion stimulus. (PMID:2359382); Neurologic Clinics [1990, 8(2):261-268];
  12. Jacobson, Gary P., McCaslin, Devin L., Patel, S., Barin, Kamrin, Ramadan, Nabih M.: Functional and Anatomical Correlates of Impaired Velocity Storage; J Am Acad Audiol 15:324–333 (2004) Link
  13. Wood, S. J, Reschke, M. F.; Kaufmman, G. D, Black, F. O., Paloski, W. H.: Binocular Coordination of the Human Vestibulo-Ocular Reflex during Off-axis Pitch Rotation; NASA Technical Report Server (NTRS) Link
  14. Wood, Scott J.,Reschke, M. F., Clément, Gilles: Tilt and Translation Motion Perception During Off-Vertical Axis Rotation Experimental Brain Research,  Exp Brain Res (2007) 182:365–377
  15. Peng, G.C.Y., Baker, J.F., Peterson, B.W.: Dynamics of Directional Plasticity in the Human Vertical Vestibulo-Ocular Reflex; Journal of Vestibular Research, vol. 4, no. 6, pp. 453-460, 1994
  16. Cohen, B.: Obituary of Jan Parmentier; ENT; Link
· Vestibular NKI Post I-Portal
  1. Michael A. Holliday, MD, Hung Jeffrey Kim, MD, Christopher K. Zalewski, PhD, Talah Wafa, AuD, Ramita Dewan, Kelly A. King, PhD, Carmen C. Brewer, PhD, John A. Butman, MD, PhD, Ashok R. Asthagiri, MD: Audiovestibular Characteristics of Small Cochleovestibular Schwannomas in Neurofibromatosis Type 2; Otolaryngology–Head and Neck Surgery 2014, Vol. 151(1) 117–124, DOI: 10.1177/0194599814529081
  2. Kiderman A: Vestibular testing: where we are, what’s ahead. Vestibular Viewpoint, 12(2):10, 2010.
  3. González, J.E. & Kiderman, A.. ENG/VNG (Diagnostic Procedure: Electronystagmography / Videonystagmography). In S.E. Kountakis (Ed.), Encyclopedia of Otolaryngology, Head and Neck Surgery (pp. 785-792). Berlin: Springer-Verlag. 2013
  4. González, J.E. & Kiderman, A. Rotary chair (Diagnostic Procedure). In S.E. Kountakis (Ed.), Encyclopedia of Otolaryngology, Head and Neck Surgery (pp. 2321-2330). Berlin: Springer-Verlag. 2013
  5. González, J.E., King, J.E., & Kiderman, A. Subjective Visual Vertical (SVV) patterns obtained using different translation times during unilateral centrifugation (UC) testing. Journal of the American Academy of Audiology, 25(3), p. 253-260. 2014
  6. Furman J, Roxberg J, Shirey I., Kiderman A, The computerized rotation head impulse test (crHIT), Journal of vestibular research, Volume 24, Numbers 2,3, 2014, Specials issue, Abstracts from XXXVIII Barany society meeting, Buenos Aires, Argentina, May 25-28, 2014
  7. Peterka R, Brown J, Doucette S, Kiderman A: Assessment of clinical potential of a new rotation test of asymmetric vestibular function, American Balance Society Meeting, 2010
  8. González JE, Kiderman A: Continued development of the rotational Head Thrust Test (rHTT): vestibular patient data, American Balance Society Meeting, 2010
  9. Gonzalez J, Kiderman A: Development of a normative percentage of saccadation during smooth pursuit testing. XXVI Bárány Society Meeting, Reykjavik, Iceland, August 2010
  10. Gonzalez J, Kiderman A: The use of ocular counterroll and horizontal nystagmus patterns in trapezoidal eccentric rotation as indicators of canal and utricular function. XXVI Bárány Society Meeting, Reykjavik, Iceland, August 2010
  11. Mango H, Makuta C, Kiderman A: Interpretive considerations and corresponding practical implications upon conducting static Subjective Visual Vertical and dynamic Unilateral Centrifugation with Subjective Visual Vertical test, American Balance Society Meeting, 2011
  12. Gonzalez J, Kiderman A: Normative data for rotational chair testing obtained by VNG technology, American Balance Society Meeting, 2011
  13. Gonzalez J, King J, and Kiderman A: The effect of translation time between eccentric positions on ocular counteroll patterns and Subjective Visual Vertical (SVV) obtained during unilateral centrifugation testing XXVII Bárány Society Meeting, Sweden Uppsala, 2012
  14. Gonzalez J, King J, and Kiderman A: Subjective Visual Vertical (SVV) patterns obtained using different translation times during unilateral centrifugation (UC) testing, American Balance Society Meeting, 2013
  15. Kiderman, Alexander, Jorge E. González, Kathleen McNerney, Assessing the clinical utility of the fast component of optokinetic nystagmus (OKN). American Balance Society Meeting, 2014
  16. Grace J, Kiderman A, Setting The Patient Straight: A Unique Approach To Vestibular Rehabilitation, Balance and VOR Therapy Orlando 20
  17. Christy, Jennifer B. PT, PhD; Payne, JoAnne MA, CCC-A; Azuero, Andres PhD, MBA; Formby, Craig PhD: Reliability and Diagnostic Accuracy of Clinical Tests of Vestibular Function for Children; Pediatric Physical Therapy: Summer 2014 – Volume 26 – Issue 2 – p 180–189;
  18. Arshad Q., Kaski D., Buckwell D., Faldon M.E., Gresty M.A., Seemungal B.M., Bronstein A.M.: A New Device to Quantify Ocular Counterroll Using Retinal Afterimages; Audiol Neurotol 2012; 17:20–24 (DOI:10.1159/000324859)
  19. Myunggi Moon MD, Sun O Chang MD, PhD, Min-Beom Kim MD, PhD: Diverse clinical and laboratory manifestations of bilateral vestibulopathy 12 MAR 2016; DOI: 10.1002/lary.25946; The Laryngoscope
  20. Wilkes, Bradley J., Carson, Tana B., Patel, Kunal P., Lewis, Mark H., White, Keith D.: Oculomotor performance in children with high-functioning Autism Spectrum Disorder; Research in Developmental Disabilities; Volume 38, March 2015, Pages 338–344. Link
  21. McNerney, Kathleen M, Coad, Mary Lou, Burkard, Robert: The Influence of Caffeine on Rotary Chair and Oculomotor Testing; Journal of the American Academy of Audiology; Volume 29, July/August 2018, Pages 587 – 595. Link
  22. Chen, TS, Han, X, Liu, Q, Li, SS, Wen, C, Wang, W, Xu, KS, Lin, P: A pilot study of the unilateral centrifugation subjective visual vertical in healthy young people; Chinese Journal of Otorhinolaryngology Head and Neck Surgery; Volume 7, November 2018, Pages 811 – 814. Link
· Eye Tracking
  1. Moore, S., Haslwanter, T., Curthoys, I., Smith, S.: A geometric basis for measurement of three-dimensional eye position using image processing. 1996. Link
  2. MacDougall, H.: Head Sets 2003 (Download PDF)
  3. Socius Partners; Goggle Opportunity Report June 26, 2005 (Download PDF)
  4. Long O, Tonguz OK, and Kiderman A: A high speed eye tracking system with robust pupil center estimation algorithm, Proc. of the 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Lyon, France, Aug. 2007 Link
  5. Long O, Tonguz OK, and Kiderman A: Real time pupil size monitoring as a screening method for diabetic retinopathy, IEEE Biomedical Circuits and System Conference, Montreal, Canada, Nov. 2007 Link
  6. Long X, Kiderman A., Kovaˇcevi´c J, and Ozan K: A new calibration method based on pupil shape constraint for eye-tracking systems, IEEE Transactions on Biomedical Engineering, 2010
  7. Pickworth, Wallace B., Murillo, Rudy: Pupillometry and Eye Tracking as Predictive Measures of Drug Abuse; Pharmacokinetics and Pharmacodynamics of Abused Drugs, edited by Steven B. Karch, MD, FFFLM, Chapter 7, pp.127-142
  8. Ortube, M.C., Kiderman, A., Eydelman, Y., Yu, F., Aguilar, N., Nusinowitz, S., Gorin, M.: Comparative Regional Puillography as a Noninvasive Biosensor Screening Method for Diabetic Retinopathy; Investigative Ophthalmology and Visual Science, January 2013 Vol 54, No.1
· mTBI & Concussions
  1. Casto, Kristen L ; Nedostup, Amy E ; Byrne, Clyde D: Auditory, Vestibular and Cognitive Effects due to Repeated Blast Exposure on the Warfighter; 1 Jul 2012-31 Sep 2012; Link
  2. McKinnon, B.J., Kiderman, A., Ives, T.E.: Neuro-otologic Test Center Evaluation in Mild Traumatic Brain Injury; Link
  3. Laura Lei-Rivera, John Sutera, Jessica A. Galatioto, Bryan D. Hujsak, James M. Gurley: Special tools for the assessment of balance and dizziness in individuals with mild traumatic brain injury; NeuroRehabilitation 32 (2013) 463–472; DOI:10.3233/NRE-130869
  4. Hoffer, M.E., Schubert, M.C., Balaban, C.D.: Eary Diagnosis of Traumatic Vestibulopathy and Postconcussive Dizziness; Neuro Clinical (2015). Link
  5. Kelly, K., Kiderman, A., Akhavan, S., Quigley, M., Snell, E., Happ, E., Synowiec, A., 
Miller, E., Bauer, M., Oakes, L.,
Eydelman, Y., Gallagher, C., Schroeder, J. H., Ashmore, R.: Oculomotor, Vestibular, and Reaction Time Testing in Teenage Athletes After Sport-Related Concussion. (In review);
  6. Kocher, C., Kiderman, A., Gonzalez, J.: Ocular Motility Following Sport-Related Impacts. (By request)
  7. Balaban, C., Hoffer, M. E., Szczupak, M., Snapp, H., Crawford, J., Murphy, S., … Kiderman, A. (2016). Oculomotor, Vestibular, and Reaction Time Tests in Mild Traumatic Brain Injury. PLoS ONE, 11(9), e0162168.  Link
  8. Hoffer, M. E., Balaban, C., Szczupak, M., Buskirk, J., Snapp, H., Crawford, J., Wise, S., Murphy, S., Marshall, K., Pelusso, C., Knowles, S. and Kiderman, A. (2017), The use of oculomotor, vestibular, and reaction time tests to assess mild traumatic brain injury (mTBI) over time. Laryngoscope Investigative Otolaryngology, 2: 157–165. doi:10.1002/lio2.74 Link
  9. King, J. E., Pape, M. M., Kodosky, P.N. (2018), Vestibular Test Patterns in the NICoE Intensive Outpatient Program Patient Population. Military Medicine, Volume 183, Issue suppl_1, 1 March 2018, Pages 237–244. Link
  10. Kelly, K. M.; et al; (2018), Oculomotor, Vestibular, and Reaction Time Effects of Sports-Related Concussion: Video-Oculography in Assessing Sports-Related Concussion. Journal of Head Trauma Rehabilitation. September 18, 2018. Link
  11. Balaban, C. D., Kiderman, A., Szczupak, M., Ashmore, R. C., Hoffer, M. E. (2018), Patterns of Pupillary Activity During Binocular Disparity Resolution. Frontiers in Neurology. November 26, 2018. Link

Also see the Posters section for additional resources.

· Diabetic Retinopathy/Pupillography

Maria Carolina Ortube, Alexander Kiderman, Yakov Eydelman, Fei Yu, Nelson Aguilar, Steven Nusinowitz, and Michael B. Gorin, Comparative Regional Pupillography as a Noninvasive Biosensor Screening Method for Diabetic Retinopathy, IOVS January 2013 54:9-18; published ahead of print November 15, 2012 Link

· Oculomotor/ Ocular Motor Testing, Neurology and Neurologic Pathways
  1. Büttner-Ennevera JA.  A review of Otolith Pathways to Brainstem and Cerebellum.  ANYAS 871: 51-64, 1999.
  2. Middleton FA, Strick PL. Basal Ganglia and Cerebellar Loops: Motor and Cognitive circuits. Brain Res Rev 31: 236-250, 2000.
  3. Krauzlis RJ.  Recasting the Smooth Pursuit Eye Movement System.  J Neurophysiol 91: 591-603, 2004.
  4. Leigh RJ, Zee DS.  The Neurology of Eye Movements 4th ed.  Oxford University Press, 2006.
  5. McDowell JR, Dyckman KA, Austin BP, Clementz BA.  Neurophysiology and Neuroanatomy of Reflexive and Volitional Saccades:  evidence from studies of humans.  Brain and Cognition 68: 255-270, 2008.
  6. Munoz DP, and Everling S.  Look away: the Anti-saccade Task and the Voluntary Control of Eye Movement.  Nature Reviews Neuroscience 5:219-228, February 2009.
  7. Maruta J, Ghajar J. Detecting Eye Movement Abnormalities from Concussion. Prog Neurol Surg. 2014; 28:226-33.
White Papers & Case Studies
  • NKI Case Study – NEURO-OTOLOGIC TEST CENTER EVALUATION IN MILD TRAUMATIC BRAIN INJURY. The ability to compare test data for an individual who was part of a normative data collection program was unexpectedly valuable when the subject later suffered a concussion and was subsequently retested repeatedly over time, revealing varied changes in test performance over time. Read
  1. Balaban, C, Kiderman, A, Szczupak, M. and Hoffer, M. A Disparity Fusion Test for Objective Diagnosis of Vergence Abnormalities After Mild Traumatic Brain Injury. Poster presented at: The 41st Annual Mid-Winter Meeting of the Association for Research in Otolaryngology ; 2018 Feb 10-12; San Diego, CA. ARO 2018 Vergence Steps – Poster