Innovative Measures of Speech and Swallowing Dysfunction in Neurological Disorders

Speech and swallowing abnormalities are important symptoms associated with disorders of the
central nervous system, motor neuron disease (such as amyotrophic lateral sclerosis),
myasthenia gravis, and primary muscle conditions. In addition to characterizing the evolution
in muscle architecture that could underlie associated orofacial weakness, identifying new
ways to measure these abnormalities is critical to the development and testing of novel
treatment approaches. As painless, non-invasive, portable technologies, quantitative
ultrasonography (QUS) and electrical impedance myography (EIM) could meet the need for
objective measures of speech and swallowing dysfunction.

In QUS, acoustic energy is applied to a muscle of interest; the resultant pictorial data are
translated into a single value that reflects the health of the imaged muscle. Similarly, in
EIM, a high-frequency, low-intensity alternating electrical current is applied to individual
muscles, and the resulting voltages measured. Impedance values reflect changes in muscle
architecture, including fiber atrophy, inflammation, and the replacement of muscle with fat
or connective tissue. Both of these user-friendly methods can provide sensitive indicators of
neuromuscular disease status when applied to the limbs. Although they have also been used to
evaluate orofacial muscles in healthy volunteers and patients with primary muscle disorders,
they have not yet been systematically studied in patients with a range of neurological
conditions.

When applied to muscles of the face and tongue, such tools could 1. Improve accuracy of early
diagnosis; 2. Allow monitoring of speech and swallowing dysfunction over time; 3. Help
individualize care; and 4. Serve as biomarkers in clinical trials. We propose that QUS and
EIM will provide convenient, reliable, clinically meaningful surrogate markers of orofacial
dysfunction in a variety of neurologic conditions.

Inclusion Criteria:

- Established, or clinically probable, neurologic diagnosis with at least the potential
for associated bulbar dysfunction

- Age 20-90 years

Exclusion Criteria:

- History or presence of a medical condition that substantially impacts bulbar function

- Age under 20 or over 90 years