Date: February 3, 2023, from 12pm to 2pm US ET
Description: OTs trained in Sensory Integration identify some life-long motion sensitivity and balance problems as gravitational insecurity (GrI). In children, GrI presents as a reluctance to move the head out of an upright orientation, e.g., to lay back, as well as in sensitivity to some motions. These children often refuse to climb, swing, skate, or bike; they may be teased about their clumsiness and/or non-participation in sports (May-Benson & Koomar 2007). Adults with this condition fear and avoid activities that challenge balance, such as standing on one foot, being on a raised, unstable, or moving surface or maintaining body stability when leaning over to perform instrumental activities of daily living.
These symptoms of GrI have been ascribed to an “oversensitivity” to gravitational cues supposedly related to primary otolith organ dysfunction. However, this hypothesis is problematic because a signal from the semicircular canals is required to distinguish head tilt (rotation) from linear acceleration. Amplification of this signal as required for small, slow head rotations is carried out by a brainstem vestibulo-cerebellar circuit for vestibular velocity storage (VVS) that boosts signal gain (magnitude) and time constant (persistence). Indeed, a neuroscientific-OT collaborative study with Dr. Teresa May-Benson on people with mild GrI found their VVS to be “underpowered” (Potegal et al 2022). They appear to compensate by using more effortful hip strategies of balance, as determined by a posturography test not previously used with GrI. Mild GrI was also found to be associated with spatial orientation problems, likely involving vestibular projections ascending to cortex, but not with general hypersensitivity or anxiety.
In the first part of the presentation, Prof. Potegal will briefly review vestibular end-organ anatomy, VVS function and ascending vestibular pathways on an understandable level. He will discuss the GrI study and the differences between study findings and the emotional/behavioral profile of child and adult clients with more severe GrI typically seen OT clinics. However, the 2022 study leaves open the possibility that gravity-detection by the otolith organs is also dysfunctional in GrI. Fortunately, this hypothesis can be assessed directly with a perceptual test. Importantly, this test is done seated and involves no movement, so people with GrI should be more willing to participate. In the second part of the presentation Prof. Potegal and panelists will discuss this prospective study. Participants are encouraged to think about being in such a study, either as people who experience GrI themselves or as researchers who will test study participants at their own locations.
Outline / Agenda:
- Identify the signs of GrI in adults
- List the signs of GrI in children
- Name the 3 sensory systems that control balance
- Identify the vestibular end-organs in pictures of the inner ear
- Explain the gravitational and linear or rotational acceleration signals transduced by each vestibular end-organ
- Describe how the semicircular canals disambiguate gravitational vs linear acceleration signals
- Explain how the brainstem VVS circuit amplifies small, slow head movement signals using the technical terms “gain” and “time constant”
- Answer the thought question: Does an “underpowered” VVS produce a hyper- or hypo-sensitivity to gravitational signals?
- Explain the findings of Potegal et al (2022) on the use of hip strategies of balance in GrI
- Describe the 3rd factor explanation for the clinical association between GrI and anxiety
- Explain how the visual vertical test can be used to assess otolith end-organ function in GrI
- Decide if you want to participate as subject and/or researcher in a prospective visual vertical test of people with GrI
Assessment: Completion of Feedback Form
Certificate of attendance will be provided
Provider Name: The Maude Le Roux Academy
Presenter: Mike Potegal, PhD, Assoc. Prof ad Honorem, University of Minnesota
After earning a BS in physics, Prof. Mike Potegal’s research career as a behavioral neuroscientist began at MIT where his thesis project involved finding the neural basis of egocentric orientation, a system in which the observer is the center of the spatial coordinate system. Egocentric orientation could logically involve the integration of vestibular input over time into a sense of distance and direction. Mike’s neurophysiological post-doc work at the Columbia College of Physicians and Surgeons and the University of Amsterdam demonstrated just such input to the system, as did subsequent behavioral testing of rats with surgically altered vestibular function. These experiences prompted his great interest in gravitational insecurity (GrI) when OT Teresa Nicols first told him about the condition years later. Having been persuaded that GrI is real nosological entity by a survey he did of OTs’ experiences with children, he and his students in the OT Masters Program at the University of Minnesota then determined that anomalies in vestibular “velocity storage” (integration over time) may be a pathophysiology underlying GrI. Mike is committed to a deeper understanding of this condition, including possible dysfunction of otolith organ input, and to bringing OT-defined GrI to the attention of the larger health-provider community.
In the other line of Mike’s research life, he has pursued the internal motivational mechanisms that control overt angry and aggressive behaviors in people and other animals. After mid-career retraining in clinical psychology and work as a pediatric neuropsychologist, these interests in motivation and behavior led to studies of children’s tantrums, the Anger-Distress Model of tantrums and some media attention to the results. He generally refrains from having tantrums when discussing GrI.
Panelists: Sarah Schoen PhD, OTR
Dr. Schoen is the Director of Research at STAR Institute. She is an occupational therapist with over 30 years of clinical experience and a doctorate in occupational therapy from New York University (2001). She completed a two-year post-doctoral fellowship awarded by the Developmental Psychobiology Research Group at the University of Colorado Health Sciences Center, Department of Psychiatry, under the mentorship of Dr. Lucy Jane Miller. She is a co-author of the Sensory Processing 3 Dimensions Scale currently being standardized by Western Psychological Services. Dr Schoen is an Associate Professor at the Rocky Mountain University of Health Professions and has served on multiple doctoral committees. She is nationally recognized for her research, educational programs and clinical expertise and has co-developed and teaches the monthly Advanced Mentorship trainings at STAR Institute. Her resume includes over 50 published peer reviewed articles as well as authoring multiple chapters on sensory integration and the STAR Frame of Reference. Dr. Schoen received the Recognition of Achievement Award from the American Occupational Therapy Association in 1997, the Virginia Scardina Award of Excellence in 2011 and the A. Jean Ayres Award in 2022, both from the American Occupational Therapy Foundation.
Dr. Teresa May-Benson, ScD, OTR/L, FAOTA
Dr. May-Benson is a well-known lecturer and researcher on sensory integration. She is author of the Test of Ideational Praxis, the Motor Planning Maze Assessment, Adult/Adolescent Sensory History, the GI-Assessment, and numerous book chapters and articles related to praxis, ideation, and sensory integration. She has extensive experience with children and adults with autism and a diverse clinical background having worked in private and public-school settings as well as private practice.
Maude Le Roux, OTR/L
Maude Le Roux is an inspiration to many professionals and parents across the globe. Her workshops are popular and previous feedback included much praise. Maude was born and raised in South Africa and graduated from the University of Stellenbosch in Cape Town in 1984. She opened her center, A Total Approach, in September 2001.
She opened the Maude Le Roux Academy online in January 2019. Maude has presented at conferences in a variety of settings across the US and also internationally. She has co-authored the book, The Listening Journey, with Francoise Nicoloff, and her second book, Our Greatest Allies, is now available on Amazon.com.
Special Needs Accommodation: We invite anyone who may need a specific accommodation to contact [email protected] and we will do our best to accommodate your needs.
Cancellation policy: This webinar is provided at no charge to participants. If you cannot attend on the specific time and date, please still register o receive the recording
Target Audience: Occupational Therapists, Speech Language Pathologists, Physical Therapists, Social Workers, Psychologists, Educators, Parents
Educational Level: Intermediary
Number of Participants: Unlimited
Instructional Methods: PowerPoint, Panel Discussion, Q and A
Contact Hours: 2
Fee: No Charge