The role of the inner ear in Dyslexia and ADHD
Understanding how the vestibular works and, more importantly, how it affects our functioning makes it easier to understand why it is implicated in syndromes like dyslexia and ADHD. It also helps to explain why and how certain, specific movements improve vestibular functioning and make positive differences to children struggling at school.
The role of the inner-ear or vestibular system underlying cognitive and behavioral disorders and their treatment has been studied by many gifted clinicians and therapists. However, the role of both the inner-ear and cerebellum (the ‘small brain’ at the base of the larger cerebrum) in determining ADHD dates back to the pioneering dyslexia research of Frank and Levinson initially published in 1973, and then evolving over four decades. By recognizing that dyslexia and ADHD are significantly overlapping disorders characterized by imbalance and poor coordination, Levinson proposed that both disorders stem from one common impairment– a signal-scrambling dysfunction of inner-ear/cerebellar origin. His ADHD data and concepts were published in numerous papers and books. Significantly, these concepts are consistent with the cerebellar research of Noble Laureate Sir John Eccles and outstanding others as well as inner-ear clinicians called neurotologists, hence gaining their support.
Levinson explained the ‘signal-scrambling’ as follows: “Just imagine the symptoms induced by spinning until dizzy. When dizzy you can’t properly read, write, speak, recall, think, plan, concentrate, orient, balance and coordinate. It’s as if the signals transmitted to varied brain structures are ‘dizzy’ or scrambled and so cannot be normally processed. They thus induce temporary dyslexic or ADHD-like states. It’s the dizzy or scrambled signals that are considered etiologically most important, not necessarily the conscious sensation or experience of dizziness which may lessen, disappear or be absent. “This analogy also explains how and why signal stabilizing medications, including inner-ear enhancing antihistamines and stimulants, are so effective in treating both dyslexia and ADHD. And it further explains the efficacy of anti-vertigo therapies in preventing the inner-ear triggered reading reversals (“space dyslexia”) and impaired concentration, orientation and balance (“space ADHD”) in orbiting astronauts.
There isn’t enough recent research to support Levinson’s findings but a 2013 study by Jean Hebert and colleagues published in Science provided important experimental evidence that a genetically induced inner-ear impairment in mice was linked to hyperactivity and thus might cause ADHD in humans.(http://www.einstein.yu.edu/news/releases/932/inner-ear-disorders-may-cause-hyperactivity/