I am in the process of getting my BRS-S. I have wanted to specialize in dysphagia for a long time, but finally worked up the courage to actually start it. As I’m working towards the BRS-S, I have several projects that need to be initiated. One of those projects for me was to start a journal club. I sent out 75 surveys and invitations, of which I received 7. Of those 7, only about 4 people were interested. I finally set the journal club for January 15, 2011, with about 7-8 people attending. When it came down to it, I sat at Ihop alone, with my computer and my journal article. I sat for an hour. The only good thing about that day was that I had a good breakfast.
I decided since I did all the work I would post my journal article review on my blog. What better way to reach more than 7-8 people?? That is if anyone even reads this! Hahaha.
My article was Swallowing and Dysphagia Rehabilitation: Translating Principles of Neural Plasticity into Clinically Oriented Evidence by JoAnne Robbins, Susan G. Butler, Stephanie K. Daniels, Roxann Diez Gross, Susan Langmore, Cathy L. Lazarus, Bonnie Martin-Harris, Daniel McCabe, Nan Musson and John Rosenbek from the Journal of Speech Language and Hearing Research 2008; 51; S276-S300.
Basically this article is to encourage SLP’s to look further into the principles of Neural Plasticity and to gain more evidence into the 10 principles. The swallow was once looked upon as a sequence of reflexive events, but we’re now finding that the swallow may be more controlled than once believed.
Neural plasticity refers to the ability of the brain to change.
The 10 principles of plasticity are 1.) Use it or lose it, 2.) Use it and improve it, 3.) Plasticity is experience specific, 4.) Repetition Matters, 5.) Intensity matters, 6.) Time matters, 7.) Salience matters, 8.) Age matters, 9.) Transference and 10.)Interference.
For principle 1, Use it or Lose it, the simple act of swallowing will not improve the swallow in a person with dysphagia. They need to use the function with increasing competence. The question remains what are the best treatment strategies for swallowing. It makes sense that those patients that are NPO and have not swallowed in years will “lose” their swallow function. Simple saliva swallowing drills can help a person return to oral feedings.
Principle 2, Use it and improve it, there are many different treatment techniques including expiratory muscle strength training, lingual strengthening, Shaker, Mendelsohn, Masako and effortful swallow. Keep your patients swallowing to strengthen those muscles, but as they swallow, challenge the patient and challenge the swallow system. To merely sit and observe as a patient eats a meal is by no means therapeutic. To feed a patient during a meal is by no means therapeutic. Building the competence of a system is imperative, not just allowing a patient to complete the simple act of swallowing.
Principle 3, Plasticity is experience specific, to focus and rehab the swallow may or may not affect other aspects, such as dysarthria or voice deficits and vice versa. Does simply completing OME with patients improve the swallow?? If we have the patient complete voice exercises, that do not involve the swallow, how will that improve the swallow function. It’s a different function to complete the exercises without a bolus than it is with a bolus.
Principle 4, Repetition matters, number of repetitions of an exercise will affect the neural changes made by that exercise. Many of the effective exercises involve systematic repetition such as LSVT, isometric lingual exercises and the Shaker. Simply completing a movement or an exercise 10 times 3 times a day may not cut it. The Shaker uses 90 repetitions and 3 repetitions of holding the head up and seems far more effective than simple OME alone.
Principle 5, Intensity matters, there is building evidence that intensity is critical for swallowing therapy. Evidence is still pending for particular dosage recommendations that are therapeutic for the swallow. If you are training for a fight, to run, to lift weights, etc, how can you improve without an intense workout. We’re working with a muscular system with swallowing and should apply the same exercise science rules to swallowing as we do to any other training.
Principle 6, time matters involves the length of your session. A person is going to benefit more from a longer session, 30-60 minutes then they will a 15 minute session.
Principle 7, Salience matters, therapy has to be purposeful for swallowing. You can’t have the person stick out their tongues 15 times and expect their swalow to improve. Simple, repetitive movements and strength training are likely not going to improve swallow function.
Principle 8, Age matters, although neural plasticity does occur throughout the lifespan, a younger system will be more responsive to the changes. This may imply that older adults need a more strenuous or a program with a greater length of time.
Principle 9, transference defined as “the ability of plasticity within one set of neural circuits to promote concurrent or subsequent plasticity.” Evidence from NMES (neuro muscular electrical stimulation) applies to this principle. This continues to be a principle that needs further investigation for implications to the swallowing system.
Principle 10, interference results from inappropriate use of E-stim. E-stim can either facilitate or inhibit the corticobulbar excitability. A simple change in Hz can change the excitability which is why there is extensive study out there now on NMES.
These principles can and should be incorporated into therapy. The more a therapist understands the swallowing system, exercise physiology and neural plasticity, the better prepared they are to treat a dysphagic patient.
Bonnie Martin-Harris and colleagues found 14 physiologic components in the swallowing system,
~hold position/tongue control
~bolus transport/lingual motion
~initiation of pharyngeal swallow
~soft palate elevation and retraction
~anterior hyoid excursion
~pharyngeal stripping wave
~pharyngoesophageal segment opening
~tongue base retraction
Our role as a therapist is to improve the strength, duration and timing of the swallowing movements, with regards to the above components.
We have different options with different interventions including bolus effects by altering volume, viscosity, thermal, taste, tactile or temperature. We can use e-stim. Compensatory strategies including the chin tuck, head rotation, head tilt, head back and side lying positions. We can use maneuvers such as the Mendelsohn, Supraglottic swallow, Super Supraglottic swallow, effortful swallow, double swallow or the Masako. We also use lingual exercises and the Shaker.
The Mendelsohn can alter the extent and duration UES opening as well as aiding in hyolaryngeal excursion.
The supraglottic and super supraglottic swallows facilitate the timing and extent of laryngeal closure at specific levels of the larynx.
The effortful swallow help to increase base-of-tongue retraction and results in increased tongue propulsive force, increased oral pressure, duration and extent of hyoid movement and laryngeal vestibule closure, longer duration of pharyngeal pressure and UES relaxation.
The tongue hold maneuver increases anterior motion of the posterior pharyngeal wall at the level of the tongue base.
You can find increased tongue base-pharyngeal wall pressure and contact duration when performing the effortful swallow, tongue-hold, Mendelsohn and super supraglottic swallow.
Robbins and her group demonstrated that lingual muscles have a propensity for increasing strength and mass and that as a result of non-swallowing exercises, improvement in swallowing pressures on liquid boluses occurred, penetraion Aspiration Scores were reduced and dysphagia-specific quality of life improved.
The Shaker exercise increases swallowing function through decreased aspiration following the swallow.
There is still a need for research from this article including looking at variables of repetition, intensity and time for rehabilitation and finding the appropriate site, stimulation frequency, amplitude, phase duration, optimal frequency and length of an individual stimulation treatment including potential effects.
When presented with a patient with dysphagia, research the disorder. If you are requesting an MBSS ask that the therapist look at muscle movement rather than just the absence or presence of aspiration/penetration. Treat the system as a whole and as a muscular system. We can actually learn much from our PT and OT friends on exercise physiology and use that to design our dysphagia therapy programs to better serve our patients.
Article and references can be found at: http://jslhr.asha.org/cgi/content/full/51/1/S276.