Leonard P. Rybak, MD, PhD

Research Professor, Department of Otolaryngology Head and Neck Surgery

    About me

    Dr. Leonard P. Rybak is a research professor and ear, nose and throat specialist whose general otolaryngology practice focuses on sinus disease and obstructive sleep apnea. Dr. Rybak received his medical degree from the Medical College of Wisconsin-Milwaukee and completed his internship at Hennepin County Medical Center in Minneapolis. He completed a residency in otolaryngology and also obtained a PhD at the University of Minnesota-Minneapolis.

    Dr. Rybak served as an assistant professor of otolaryngology at the University of Minnesota prior to coming to the SIU School of Medicine. Dr. Rybak's professional affiliations include the American College of Surgeons, and the American Academy of Otolaryngology - Head and Neck Surgery. Locally, he is a member of the Sangamon County Medical Society and of various committees at St. John’s Hospital and the SIU School of Medicine. He serves as president of the Sangamon County Chapter of the Society for Neuroscience.

    As a clinician and surgeon, Dr. Rybak's special interests include general otolaryngology and sleep apnea. Known both nationally and internationally for his research in the field of otolaryngology, Dr. Rybak has published and presented numerous articles and chapters dealing with various aspects of ear, nose and throat diseases. He is certified by the American Board of Otolaryngology.

    Research Interests/Areas of Expertise:

    • Growth of cochlear hair cells derived from Immortomouse (HEI-OC1, OC-k3 cells) in culture
    • Ototoxicity of cisplatin, carboplatin and loop diuretics and chemoprevention
    • Mechanisms controlling free radical production within the cochlea
    • Auditory development and ototoxicity during development
    • Scanning and transmission electron microscopy of the cochlea
    • Mechanisms of noise-induced hearing loss and pharmacological prevention
    • Cell death and cell replacement pathways in the cochlea



    Education & training

    Board Certifications
    Medical School
    Medical College of Wisconsin, Milwaukee, WI
    University of Minnesota, Minneapolis, MN - Otolaryngology


    Research Interests
    Sinusitis, Sleep Apnea, Thyroid Cancer, and Pediatric Otolaryngology



    Jiang P, Ray A, Rybak LP Brenner M:  Role of STAT1 and Oxidative Stress in Gentamicin-Induced Hair Cell Death in Organ of Corti, Otol Neurotol : October 2016 - Volume 37 - Issue 9 - p 1449–1456

    Kaur T, Borse V, Sheth S, Sheehan K, Ghosh S, Tupal S, Jajoo S, Mukherjea D, Rybak L P, Ramkumar V.:  Adenosine A1 Receptor Protects Against Cisplatin Ototoxicity by Suppressing the NOX3/STAT1 Inflammatory Pathway in the Cochlea.  J Neurosci  36:3962-3977, 2016.

    Fox DJ, Cooper MD, Speil CA, Roberts MH, Yanik SC, Meech RP, Hargrove TL, Verhulst SJ, Rybak L P , Campbell KCM.  D-Methionine Reduces Tobramycin-induced Ototoxicity without Antimicrobial Interference in Animal Models.  Journal of Cystic Fibrosis 2015, Jul 9. pii: S1569-1993(15)00158-7. doi: 10.1016/j.jcf.2015.06.005..


    Monsell, EM, Cass, S, Rybak, LP,Nedzelski, JM: Chemical Treatment of the Labyrinth, In:  D.E. Brackman, C. Shelton, and M. Arriaga (eds)  Otologic Surgery, Fourth edition, Elsevier, Philadelphia, pp. 431-444, 2016.

    Ramkumar V, Borse V, Ghosh S, Kaur T,  Sheehan, K,   Sheth S,   Dhukhwa A,  Tupal S, Mukherjea D, Rybak LP.:  Role of Adenosine Receptors in Auditory Functions, Chapter 9 in ; Adenosine Signaling Mechanisms: Pharmacology, Functions and Therapeutic Aspects, Nova science publishers, pages 183-192, 06/2015.

    Rybak, L.P. and Brenner MJ:  Vestibular and Auditory Toxicity, In:  Cummings C.W. et al. (eds), Otolaryngology:  Head and Neck Surgery, Sixth  Edition,  Elsevier Saunders: Philadelphia, Vol. 3, pp. 2369-2382, 2015.


    Miller J, Le Prell, C and Rybak, L (editors).  Free Radicals in ENT Pathology, Springer, New York, NY, 2015.



    Endogenous Modulation of Cochlear Injury. Leonard P. Rybak, MD, PhD,  Principal Investigator, National Institutes of Health, National Institute on Deafness and Other Communicative Disorders (R01 DC 02396-18A1, competing renewal, March 1, 2014-February 28, 2019,  total direct costs $1,062,500*.

    Transplatin:  A Novel Agent to Mitigate Cisplatin Toxicity, Vickram Ramkumar, Principal Investigator, Leonard P. Rybak, co-investigator, National Cancer Institute, R01 CA 166907-01A1, July 1, 2013-June 30, 2018, total costs $1,500,000*.

    Phase II Clinical Trials; D‐methionine to Reduce Noise‐Induced Hearing Loss. Department of Defense Kathleen Campbell PhD, PI, Co-Is Leonard Rybak, MD. PhD Joseph Milbrandt,PhD, Maj Jillyen Mathis AuD, Carrie Redlich, MD, Martin Slade MPH. ($2,568,584.99) March 1, 2011 through Feb 28, 2016*.


    Paparella Lecturer and Award Recipient, University of Minnesota Department of Otolaryngology, May 4, 2015

    Distinguished Research Award, Southern Illinois University School of Medicine, Department of Surgery; 2009