Abstract Details

Title Impedance Pharyngography to Evaluate Swallowing in Patients with Amyotrophic Lateral Sclerosis

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) P1 - Poster Session 1 (12:00 PM-1:00 PM)

Poster/Presentation
Number 1-006

Objective

The goal of this pilot study was to investigate whether impedance pharyngography (IPG) can be used to evaluate the swallowing process in ALS patients and to learn how IPG waveforms relate with videofluoroscopy data.

Background

Swallowing dysfunction develops almost universally in patients with amyotrophic lateral sclerosis (ALS). IPG is a non-invasive measurement procedure for monitoring the dynamic impedance change during the swallowing process and quantifying swallowing abnormalities.

Design/Methods

Data was collected on 8 ALS patients (5 men, 3 women, with a mean age of 70.5 years). IPG data was recorded using a continuously measuring lock-in-amplifier-based impedance measurement system. The current-injecting surface electrodes were placed bilaterally at the insertion of the sternocleidomastoid muscles, while the voltage-sensing electrodes were placed between the hyoid and larynx bilaterally. All IPG measurements were performed simultaneously with routine videofluoroscopy during swallowing food substances of different consistencies: thin liquid, nectar thick liquid, and solids.

Results

All participants tolerated the IPG procedure well. The changes in both magnitude and phase of the IPG signal from the ALS patients correlated to the chronological series of anatomical events in the swallowing process. During the pharyngeal stage, an obvious drop of the magnitude waveform and the increase of the phase waveform was observed, which likely reflecting upward and forward movement of the larynx with an increased cross-sectional area and decreased distance between the hyoid and larynx. No consistent differences of the IPG signals were found in swallowing the various substances, suggesting that this change was not related to passage of the bolus itself.

Conclusions

These initial findings suggest that IPG can be easily performed in ALS patients and correspond with the physiological swallow as observed on videofluoroscopy. Further work is necessary to learn how this measure complements standard assessments of disease status including ALSFRS-R scale.

Authors/Disclosures
Hilda V. Gutierrez, MD (Beth Israel Deaconess Medical Center) PRESENTER	Ms. Gutierrez has nothing to disclose.
	No disclosure on file
Akashleena Mallick, MD, MBBS (Massachusetts General Hospital- Harvard Medical School)	Dr. Mallick has nothing to disclose.
Badria Munir, MD	Dr. Munir has nothing to disclose.
	No disclosure on file
	No disclosure on file
Seward B. Rutkove, MD, FAAN	Dr. Rutkove has received personal compensation in the range of $50,000-$99,999 for serving as a Consultant for Myolex, Inc. Dr. Rutkove has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for American Academy of Neuorlogy . The institution of Dr. Rutkove has received research support from NIH. The institution of Dr. Rutkove has received research support from NASA. The institution of Dr. Rutkove has received research support from Blavatnik Family Foundation. Dr. Rutkove has received intellectual property interests from a discovery or technology relating to health care. Dr. Rutkove has received intellectual property interests from a discovery or technology relating to health care. Dr. Rutkove has received publishing royalties from a publication relating to health care. Dr. Rutkove has received publishing royalties from a publication relating to health care. Dr. Rutkove has received personal compensation in the range of $500-$4,999 for serving as a Grant Reviewer with NIH.