Elizabeth Erickson DiRenzo Voice Research Lab

Dr. Erickson DiRenzo's laboratory integrates research techniques from the basic and clinical sciences to improve the prevention and management of voice disorders.

The larynx is uniquely located at the divergence of the upper and lower airways and gastrointestinal tract. The vocal folds are housed within the larynx and are the only tissues in the human body that routinely vibrate at frequencies ranging from ~100-1000 Hz, in order to generate voice.

Voice disorders affect millions of people every year and have a devastating impact on communication and quality of life. Our work is focused on laryngeal mucosal biology. Specifically, we investigate the cellular and molecular events leading to the development of voice disorders and seek to identify unique mechanisms involved in protection of the vocal fold mucosa from injury.

We actively seek to translate our research findings into practical applications for other voice scientists, clinicians, and patients with voice disorders.

Research

Understanding the Composition and Regulation of the Laryngeal Mucus Layer

The vocal folds are exposed to ~25 million pollutant, viral, and bacterial insults each day and require protection from this myriad of inhaled insults. Mucus is the thin layer of fluid that covers the surface of the vocal folds and is the first line of defense in the larynx. However, an increased amount of thick, tacky mucus is commonly observed on the vocal folds in persons with inflammatory voice disorders. This phenomenon, described as “mucus aggregation,” is not trivial. Mucus aggregation is one of the most common complaints of persons with voice disorders and leads to phonotraumatic behaviors, negatively impacts vocal fold vibration and voice quality, and may even promote the accumulation of noxious irritants in the larynx. Currently, a major obstacle in treating mucus aggregation is that biological mechanisms regulation laryngeal mucus production in normal or inflamed larynges are not known. The objective of this project is to elucidate cellular and molecular mechanisms underlying laryngeal mucus production and to assess clinical mucus aggregation and vocal function during normal and inflammatory conditions.  Our findings add to the knowledge base necessary in order to develop strategies to normalize the laryngeal mucus layer. Such strategies will likely not only have a positive impact on voice production, but also overall laryngeal health. 

Collaborators: Drs. Edward Damrose, Karuna Dewan, and Kwang Sung (Stanford University) and Dr. Heather Shaw Bonilha (The Medical University of South Carolina)

Investigating the Laryngeal Health Effects of Tobacco Products

In the United States, the prevalence of conventional cigarette use among adolescents and adults remains high.  We have recently determined that a multitude of cellular and molecular changes, not surprisingly, occur in the laryngeal mucosa of mice and in laryngeal cell cultures exposed to conventional cigarette smoke.  Electronic (e)-cigarettes, also known and electronic nicotine delivery systems (ENDS), have rapidly become one of the most popular inhalants worldwide. Similar to conventional cigarettes smoke, ENDS-generated vapor is inhaled directly and mucosal surface of the respiratory tract, including the larynx, are the first set of tissues to receive this assault.  Despite the widespread use of ENDS, their effects on laryngeal health is unknown. Our long-term goal is to elucidate the effect of ENDS use on laryngeal health and to determine whether use of these devices contribute to the development of laryngeal diseases that disturb critical communicative functions. A major obstacle in achieving our long- term goal is the lack of established in vivo or in vitro models of laryngeal exposure to ENDS vapor. The objective of this project, which is a necessary first step towards our long-term goal, is to develop mouse and cell culture models of ENDS exposure that can be used to study the pathophysiological changes that may occur in the larynx of human ENDS users. Identifying the effects of ENDS on biological mechanisms that contribute to the development of laryngeal disease is of major significance for making informed clinical recommendations regard the use of these devices. 

Collaborators: Dr. Robert Jackler (Stanford University) and Dr. Laura Crotty Alexander (University of California, San Diego)

Investigating Novel Interventions for Voice Disorders

We are also interested in clinical and quality of life outcomes in patients with voice disorders undergoing surgical or behavioral interventions. One area of current focus is developing novel interventions for essential vocal tremor (EVT). Deep brain stimulation (DBS) of the thalamus has emerged as a leading and effective surgical intervention for essential tremor of the limbs. However, the effects of DBS treatment on EVT are almost entirely unknown. The objective of this project to the evaluate the effect of DBS on physiologic, acoustic, and perceptual measures of EVT. Results of this work will provide evidence regarding the promising application of DBS to address EVT in patients with essential tremor and have the potential to alter treatment paradigms for these difficult-to-serve patients.

Collaborators: Drs. Casey Halpern and Kwang Sung (Stanford University)

Publications

2016

Early Cellular Response to Radiation in Human Vocal Fold Fibroblasts.
The Annals of otology, rhinology, and laryngology
Erickson-DiRenzo, E., Enos, G., Thibeault, S. L.
2016; 125 (5): 425-432

 

2015

Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology
NEUROSURGICAL FOCUS
Ho, A. L., Erickson-DiRenzo, E., Pendharkar, A. V., Sung, C., Halpern, C. H.
2015; 38 (6)

 

Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology
NEUROSURGICAL FOCUS
Ho, A. L., Erickson-DiRenzo, E., Pendharkar, A. V., Sung, C., Halpern, C. H.
2015; 38 (6)

 

Utility of cell viability assays for use with ex vivo vocal fold epithelial tissue. 
Laryngoscope
Erickson-DiRenzo, E., Sivasankar, M. P., Thibeault, S. L.
2015; 125 (5): E180-5

 

Deep Brain Stimulation for Essential Vocal Tremor: A Technical Report. 
Cureus
Ho, A. L., Choudhri, O., Sung, C. K., DiRenzo, E. E., Halpern, C. H.
2015; 7 (3)

 

A preliminary investigation of potential biases in phonation threshold pressure analysis.
Journal of voice
Sundarrajan, A., Erickson-Levendoski, E., Sivasankar, M. P.
2015; 29 (1): 22-25

 

2014

Vocal Fold Ion Transport and Mucin Expression Following Acrolein Exposure
JOURNAL OF MEMBRANE BIOLOGY
Levendoski, E. E., Sivasankar, M. P.
2014; 247 (5): 441-450

 

Reducing the negative vocal effects of superficial laryngeal dehydration with humidification.
The Annals of otology, rhinology, and laryngology
Levendoski, E. E., Sundarrajan, A., Sivasankar, M. P.
2014; 123 (7): 475-81

 

Vocal fold epithelial barrier in health and injury: a research review.
Journal of speech, language, and hearing research : JSLHR
Levendoski, E. E., Leydon, C., Thibeault, S. L.
2014; 57 (5): 1679-91

 

2012

Influence of Obligatory Mouth Breathing, During Realistic Activities, on Voice Measures
JOURNAL OF VOICE
Sivasankar, M. P., Erickson-Levendoski, E.
2012; 26 (6)

Role for Ion Transport in Porcine Vocal Fold Epithelial Defense to Acid Challenge
OTOLARYNGOLOGY-HEAD AND NECK SURGERY
Erickson-Levendoski, E., Sivasankar, M. P.
2012; 146 (2): 272-278

 

2011

Acute Stress to Excised Vocal Fold Epithelium From Reactive Oxygen Species
LARYNGOSCOPE
Alper, R., Fu, X., Erickson-Levendoski, E., Zheng, W., Sivasankar, M.
2011; 121 (10): 2180-2184

 

Investigating the Effects of Caffeine on Phonation
JOURNAL OF VOICE
Erickson-Levendoski, E., Sivasankar, M.
2011; 25 (5): E215-E219

 

2010

Simulated Reflux Decreases Vocal Fold Epithelial Barrier Resistance
LARYNGOSCOPE
Erickson, E., Sivasankar, M.
2010; 120 (8): 1569-1575

 

Evidence for Adverse Phonatory Change Following an Inhaled Combination Treatment
JOURNAL OF SPEECH LANGUAGE AND HEARING RESEARCH
Erickson, E., Sivasankar, M.2010; 53 (1): 75-83

 

Hypertonic challenge to porcine vocal folds: Effects on epithelial barrier function
OTOLARYNGOLOGY-HEAD AND NECK SURGERY
Sivasankar, M., Erickson, E., Rosenblatt, M., Branski, R. C.
2010; 142 (1): 79-84

 

2009

Short-Duration Accelerated Breathing Challenges Affect Phonation
LARYNGOSCOPE
Sivasankar, M., Erickson, E.
2009; 119 (8): 1658-1663

 

2008

Phonatory Effects of Airway Dehydration: Preliminary Evidence for Impaired Compensation to Oral Breathing in Individuals With a History of Vocal Fatigue
JOURNAL OF SPEECH LANGUAGE AND HEARING RESEARCH
Sivasankar, M., Erickson, E., Schneider, S., Hawes, A.
2008; 51 (6): 1494-1506

Meet the Team

Elizabeth Erickson DiRenzo, PhD, CCC-SLP

Assistant Professor
Laboratory Director

edirenzo@stanford.edu

I received my Master’s degree in speech language pathology from Purdue University in 2008. I then completed my Clinical Fellowship Year (CFY) at Indiana University Health – Arnett Hospital in Lafayette, Indiana. Following the completion of my Master’s degree, I remained at Purdue and received my PhD in 2012 in laryngeal physiology with M. Preeti Sivasankar, PhD. I then completed postdoctoral training in the Department of Surgery, Division of Otolaryngology – Head & Neck Surgery at the University of Wisconsin-Madison in the laboratory of Susan L. Thibeault, PhD studying vocal fold biology. 

I joined the Stanford faculty in 2014 as an Assistant Professor. My clinical interests include the evaluation and treatment of patients with voice, resonance, airway, and swallowing disorders.


Meena Easwaran, MS

Research Associate
meenae@stanford.edu

Joshua Martinez, MS

Research Associate
joshua.martinez@stanford.edu

JOIN US

We are looking for smart, hard-working and fun individuals to join our research team. We currently have positions for undergraduates, medical students, resident physicians, fellow physicians, and postdoctoral researchers. We are looking for individuals with strong background in cellular and molecular biology, airway biology, otolaryngology, and/or speech-language pathology. For interested individuals, please send your resume/curriculum vitae and a short description of why you are interested in our research to Dr. Elizabeth Erickson-DiRenzo.

 

MAKE A GIFT

Specify “DiRenzo Voice Lab” next to “Special Instructions/Other Designation”.


By supporting our laboratory's research, you are supporting:

  1. Educating and training the next generation of laryngeal scientists.
  2. Developing innovative research technology to study laryngeal mucosal biology.
  3. Empowering our scientists in executing high-risk, high-reward experiments to make a major impact in the assessment and treatment of voice disorders.

Every dollar makes a difference in achieving these goals. Thank you for supporting our students, postdoctoral fellows, and research program.

SPONSORS

CONTACT US

DiRenzo Voice Lab
1291 Welch Rd 
Grant Building, Rm S378 
Stanford, CA 94305

 

Lab Office
801 Welch Road 
Department of Otolaryngology - Head & Neck Surgery, Rm 231
Stanford, CA 94305
(650) 498-9051