E-Stim Update: A Perspective on Ampcare, LLC

by Karen Sheffler, MS, CCC-SLP, BCS-S of SwallowStudy.com

Yes, that cute baby is there for more than just to catch your attention! As clinicians working in the field of dysphagia, we need to realize how our field is really still in its infancy (early childhood at best). Jeri Logemann started researching swallowing and swallowing disorders in the late 1970’s to early 1980’s, well within my lifetime! The field is now having a major growth spurt! Did you know that the first World Dysphagia Summit was last month in Barcelona? This surge in research causes us to have to do a lot of critical analysis of new research, new ideas and new treatment modalities (e.g., neuromuscular electrical stimulation or NMES, aka, e-stim). Please see my prior blog (New Horizons For Electrical Stimulation?) that reviewed the history and prior research on the topic of e-stim. Ianessa Humbert, PhD, CCC-SLP noted in her recent “Down The Hatch” episode on e-stim (“What’s The Deal with E-stim?”), that this is likely the most researched treatment modality, but we need to think critically about what we are treating and why. Dr Humbert also warns: “FDA approval for use doesn’t necessarily mean effective.”

With that background perspective,

I want to share my findings from the course I recently attended by Ampcare, LLC called:

“Deciphering Dysphagia with Ampcare’s Effective Swallowing Protocol (ESP™)” – presented by Russ Campbell, PT (who is the co-owner of Ampcare, along with Rick McAdoo, MS, CCC-SLP & Ronda Polansky, MS, CCC-SLP):

I gained:

1. A new listening for and a new appreciation for this modality of electrical stimulation.

2. A realization that some of the claims are an issue of semantics, and these can be cleared up.

3. An appreciation that the company is emphasizing critical thinking in the application of this device. It is not for all patients with all types of difficulties swallowing.

Ampcare’s Protocol Emphasized:

• “Once you know the physiological impairment, then you can figure out if you want to use the device or not.”
• “What is the physiological response you want and for what reason?”
• Gone are the days of throwing the electrodes everywhere to hope to “just get everything.” This protocol requires the therapist to think critically about which patients could benefit. The therapist is actively present and working with the patient the whole time on exercises and effortful saliva swallows during the intermittent stimulation for the full 30 minutes (e.g., 5 seconds of stimulation followed by 15-25 seconds of rest).
• “If you don’t see a change in 6 weeks (after making multiple modifications), then don’t continue the device and treatment protocol.”
• “Be a clinician, not a technician.”
• “We give you the sheet music, and you determine how to play it.”
• “You should question anything people are telling you.”

LET’S CLARIFY E-STIM SEMANTICS FIRST:

In the past, when any company has said that stimulation elevates the larynx and works on pharyngeal contraction, that is when therapists have put on their anatomy/physiology hats and said: “that does not make biological sense!” The electric current cannot reach that deep (as noted in my prior Facebook post from Sept 12, 2017). Research had also showed that the reverse was true, that the larynx is pulled down with some electrode placements. (See the DysphagiaGrandRounds episode on E-stim reviewing the following article by Ludlow, et al., 2007 for one example.) This has caused therapists to write-off this modality in the past.

At this Ampcare workshop, I realized that first we have to agree on HOW we describe structures and actions. Maybe the confusion was partially in the SEMANTICS!

Read on regarding how we may define “hyolaryngeal elevation” differently.

Hang in there – it gets nitty-gritty.

As noted by Dr Humbert in her “Down The Hatch” podcast, we are manipulating a person’s airway, and you could manipulate it in a good way through perturbation (a disturbance of the regular course of motion) or in a bad way.

We are all in agreement that stimulation to the paired submental muscles (under the chin) – the anterior belly of the diagastric, the mylohyoid and the geniohyoid – pulls the HYOID forward and upward, as well as depresses the mandible. With stimulation on and increasing in intensity, you first feel the tingle at the skin, then the grimace of the platysma, followed by your jaw pulling down, and finally, you can palpate your hyoid and feel it moving up and forward. I felt this on myself (see videos in the comments section on my @SwallowStudySLP Facebook post). See videofluoroscopic image of this action on Ampcare’s website: https://swallowtherapy.com/research/

Did you see the hyoid bone move on the fluoro image?

Did you notice also that the laryngeal vestibule or “airway” was stretching wider OPEN?

We all agree: Stimulation to the submental muscles “pulls the airway open,” as said by Russ Campbell, PT from Ampcare. Additionally, only PART of the larynx is elevating – the thyroid cartilage aspect of the larynx is being pulled upward and forward by the anterior/superior hyoid movement. This is explained by “anatomical inference,” per Russ, meaning that because structures are connected (by the thryrohyoid ligament), the thyroid cartilage will be yanked upward/forward too. Ampcare’s preliminary findings article from 1998 in Advance (linked on the Ampcare website) titled: “Promoting Laryngeal Elevation with E-Stim,” used a non-invasive Computerized Laryngeal Analyzer to measure the surface readings of movement of the larynx during the swallow. They noted that the “larynx” was elevating, but the superficial readings could only be detecting the thyroid cartilage moving. However, that does not mean that the entire larynx and laryngeal vestibule is elevating in the right direction (i.e., cricoid cartilage, arytenoids, false and true vocal cords, etc).

ANALYZING AMPCARE’S PRIOR CLAIMS:

At times, Ampcare uses the phrases of:

• “facilitating laryngeal elevation,”
• “facilitating the hyolaryngeal complex,” and
• “pulling the airway in the correct or right direction.”

To further muddy the waters, an article linked on their website from BioNews-Texas states: “The FDA’s approval for the ESP™ system defines it as an approach that leads to ‘muscle re-education by application of external stimulation to the muscles necessary for pharyngeal contraction,’ according to an Ampcare press release.” 

Russ Campbell, PT from Ampcare, LLC and I had a great discussion after the lecture to really clear up these website claims and the semantic issues. His lecture had cleared up some issues, as he stated that no e-stim company can claim that stimulation reaches the pharyngeal constrictors!

MORE AGREEMENTS:

-We CANNOT say it is pulling the whole larynx and laryngeal vestibule up.

-We CANNOT say it is immediately pulling the whole “hyolaryngeal complex” up.

Most speech-language pathologists would then envision a beautifully sealed off airway with the laryngeal vestibule closed up tight. That is what is expected if a company claims airway protection. This does not happen. Ampcare was maybe using the term “hyolaryngeal elevation/excursion” without realizing that SLPs may assume an immediately improved laryngeal vestibule closure.

-We agreed that the term “airway” cannot be used too loosely.

-We cannot say that the entire “airway” is pulled in the “correct or right” direction.

There is NO approximation of the arytenoids to the epiglottic petiole, NO complete epiglottic inversion, and no tight airway protective seal of the laryngeal vestibule. In looking at the videofluoroscopic swallow studies with estim on, we have not been able to see if there is any effect on the false and true vocal cords. Those with FEES plus E-stim experience, please contribute to discussion in comments section below!

–REGARDING THE PES/UES: We agreed that improved hyoid excursion MAY assist in the mechanical yanking open of the pharyngoesophageal segment (PES, aka UES or the upper esophageal sphincter). However, it does not aide in the “relaxation,” which occurs milliseconds before opening by a message from the lateral medulla in the brainstem. I suggested that they cannot keep using the terms “relaxation” and “opening” interchangeably. These are distinct, yet interacting, stages of overall UES function. I will quote an excerpt from a paper I wrote on Lateral Medullary Syndrome:

“UES opening is the ‘sum effect of the relaxation of the cricopharyngeal (CP) muscle, its pliability, and the distraction forces imparted on the sphincter’ (Shaker et al., 1997, p. G1518). Jacob, Kahrilas, Logemann, Shah and Ha (1989) also described the UES sphincter opening as an active mechanical event rather than simply a consequence of CP relaxation. This is a five step sequence: (1) Relaxation, (2) Opening, (3) Distention, (4) Collapse, and (5) Closure with sphincter contraction.”

DIFFERENT KIND OF THERAPY:

When stimulation is ON, the laryngeal vestibule is STRETCHED wide open.

That is pretty cool to be able to stretch the larynx in this fashion. As Dr Humbert said, this is airway manipulation and potentially a good perturbation. This will apply a resistance, and the patient has to work hard to overcome the opening in order to swallow.

As you could see on my Facebook videos, when stimulation was on, I felt that my first swallow was hard to complete. Subsequent swallows were easier. My system was learning how to go into overdrive to overcome the perturbation.

Perturbation Examples: It is really hard to lift a heavy suitcase when you expect it to be light. However, when you then anticipate that the suitcase is heavy, you prepare for it and lift it well. Then when the weight is less (perturbation off), the next item you will lift that suitcase well over your head. It will be so easy!

You see this idea also when a baseball batter is swinging three heavy bats to get ready to just use just one for a big hit.

The Masako exercise is another example of perturbation, as you are sticking out your tongue to make the back of your tongue work harder against this challenge to the system. However, how many repetitions can you actually get from your patient with the Masako?

See topic #7 in this prior blog that covers Dr Humbert’s presentation regarding motor learning and perturbation at the 2016 Dysphagia Research Society Meeting. 

Motor learning is needed to repeatedly lift a heavy object, but what would happen if the next weight was super light? Feed-forward processing tells us that she would launch it to the sky. Then her system would adapt.

We tell people all the time to perform an “effortful swallow,” but how do we know if they are really giving it more effort? How do we know where they are pushing harder (i.e., extra tongue push, extra throat squeeze)? Is is maladaptive? Potentially, the e-stim perturbation can focus the patient’s muscle effort in a functional rather than maladaptive way. Hopefully, more research will come on that.

With typical exercises your patient may get bored and quit after just 5-10 repetitions? Therefore, typical therapy exercises may not follow neuroplasticity principles of repetition, intensity, specificity, difficulty, and more. With non-device driven therapies there is no “dosing,” so we don’t know how hard the “hard swallow” is. There is also no way to really motivate the patient to perform a lot of repetitions.

THERAPY POTENTIAL:

This is exciting that you can potentially get up to 60-90 swallows in one 30 minute session and finally get to the Type IIb muscle fibers, per Russ. Swallowing musculature has a high overall percentage of Type IIb fibers, per Ampcare. Disuse atrophy is a shrinking of these Type IIb fibers. Normal exercise alone starts out using the less fatiguable Type I fibers, but prolonged exercise may get to the Type IIa & IIb fibers. However, if your patient stops after just 10 repetitions of a traditional swallowing exercise, you have never worked on the fast-twitch, dynamic, powerful and explosive Type IIb fibers. In other words, brief and low-intensity therapy may not be effective. Per Ampcare, using stimulation over the appropriate neuromuscular junctions/motor points plus voluntary exercises against resistance and repetitive swallowing against resistance maximizes the recruitment of Type IIb.

IDEAS for getting a lot of repetitions as dry swallows can be difficult to generate: Brush the teeth first, which will stimulate saliva production. Apply mouth moisturizer before and during the rest times. If the patient is safe for some oral intake, the patient can have sips or bites during the rest times when the stimulation is off. The ESP protocol has 15-25 second rests between stimulations.

In talking further with Russ about “facilitating laryngeal vestibule closure,” he noted that the idea was NOT to achieve the immediate result of improved hyolaryngeal elevation with e-stim on. Their goal is for the longer-term effects of improved hyolaryngeal elevation after therapy. These rehabilitation outcomes can be seen in some patients (not all), per Russ. The person is told to swallow saliva with stimulation on (with an effortful swallow or a Mendelsohn maneuver, for example), and he/she is working hard to close the airway in response to this airway opening perturbation. The thought is that with perturbing the system for the 30 minute protocol, the muscles over time will learn to move stronger and quicker.

OTHER E-STIM COMPANIES’ CLAIMS:

Another company, that-shall-not-be-named, uses the additional placement of electrodes below the thyroid. There is additional opening of the airway from below, which is due to the electrode placement over the laryngeal depressor muscles. These pull the larynx down. This other device “allows” patients to swallow a bolus of food or liquid with the airway perturbed in this fashion. Ampcare has stated that it is unsafe to swallow a bolus of food or liquid with stimulation on. I have heard people say that they like the other company, because the patient “can” swallow food/liquid with the stimulation on. I would warn, that just because the company says you “can,” doesn’t mean you should.

Let me be very clear, an open airway = bad = opposite direction your airway should go for a safe swallow = more risk for you to aspirate if you are swallowing food or liquid with stimulation on.

If the patient cannot overcome that airway manipulation or perturbation (disturbance), then eating/drinking with stimulation on may be too risky. Unless you have visualized your specific patient on a videofluoroscopic swallow study, you do not truly know if it is safe to eat with stimulation on? Are you sure that the patient is able to resist every time and close the airway? Are you sure that this same patient you saw under fluoroscopy will do that on every swallow across a long treatment session without fatigue? How about if your outpatient appointment is late in the day? What if your patient’s disease process causes such variability from one day to the next?

HOW DO I KNOW IF THIS E-STIM DEVICE IS RIGHT FOR MY PATIENT?

You select any device or treatment protocol based on the pathophysiology that was already identified on the patient’s complete swallowing evaluation, which included instrumental analysis of the underlying deficits.

Dr Humbert recommended the following in her Dysphagia Grand Rounds lecture on Estim:

Use videofluoroscopy to ensure the effectiveness, with the above caveats considered. It is helpful to initially place and train the use of any device in the clinic first. Make sure the patient is fitted with the correct size of electrodes, comfortable without pain or teeth rattling (stay off the jaw bone), and you have the appropriate settings to the point that you can palpate good hyoid movement. Then bring the patient into a videofluoroscopic swallow study and test the effectiveness of the device under fluoro. (Mobile van units are great for this at nursing facilities). Getting the device set up first, allows you to minimize radiation time while testing the effectiveness of the device. See what moves at rest with stimulation on/off. See how the patient responds with a dry swallow and an effortful with stimulation on (realizing the first swallow with stimulation on may be challenging). Does the patient compensate over time to the stretching open of the laryngeal vestibule? Are they capable of moving up the rest of the larynx to achieve full airway closure?

FUTURE RESEARCH:

Research is pending on whether it can really help speed up the laryngeal vestibule closure reaction time (LVCrt), which is the speed of closure from the point of initial hyoid movement to the point of maximum laryngeal vestibule closure. This is closure of the entire laryngeal vestibule, and not just the hyoid yanking. We all look forward to more research coming from Humbert’s lab and others. 

Dr Humbert commented that Estim is now the most researched therapeutic technique, but there is still much to learn. She is also concerned that the HYOID has become overrated! We really need to focus the attention on improved airway protection (laryngeal vestibule closure). Dr Humbert recommended her Critical Thinking in Dysphagia Management – Hopeisinthescience.com course, regarding “Ampcare training where all 3 of the 4 necessary stakeholders were included: researchers, clinicians, manufacturers (no patients). We discuss estim (AMPCARE) and a rich discussion followed,” per Humbert. (Note: as of 2020, the CTDM course is not available.)

Research is also still looking into potential sensory benefits. Does all this stimulation to the neck help the person become more aware and potentially more able to detect residue and airway invasion? We will have to wait and see.

Research methods are crucial, as simply showing a diet improvement alone does not indicate that a treatment was effective from a physiological standpoint. Scales like NOMS and FOIS also do not detect physiological changes. The Penetration Aspiration Scale (PAS) may not be sensitive enough to see improvements, as it is not a severity scale, and taking an average of scores is less meaningful. Additionally, residue needs to be an additional outcome measure, as one could have a Penetration Aspiration Scale score that is “normal,” with a pharynx full of residue due to a severe impairment.

E-STIM SUMMARY:

Electrical Stimulation is one tool in our dysphagia therapy toolbox, but what makes it work and what makes it potentially effective for your specific patient is your brain, per Russ Campbell, PT. Over the years, false claims have caused therapists to completely discredit this broad modality. Now I realize that some of these claims were semantic errors, meaning we are labeling and describing things differently!

We have to be careful to make sure we are using the correct terms to accurately state what we mean, and to not claim something that does not make biological sense. We need to challenge companies and ask questions when we find them making potentially erroneous claims.

Re-embracing this modality with a critical mind will move the field forward.

I have remained open, reviewed information with a critical (and picky) mind, and I am excited to start to see if progress can be made. We can all do research with an “N” of 1 – one patient at a time.

I look forward to further discussion on e-stim in the comments section below. 

***

Disclosures:

I do not receive any financial compensation from the above links to courses. I do peer reviewing for the DysphagiaGrandRounds.com courses.

In exchange for my critical analysis of this modality, the Ampcare company allowed me to attend their course free of charge, but they did not compensate me financially in any other way. SaveSave

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