Neuromuscular Re-education of the Submandibular Muscles to Increase Laryngeal Elevation

Using any Class II NMES Device

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Understand the anatomy and physiology of swallowing

Review principles of electrophysiology Discuss rationale for using NMES to the

submandibular region for improving laryngeal elevation

Documentation and billing specifics

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Dysphagia affects: 15 million people in the USA 45%-87% of residents in long-

term care One out of 17 people will eventually

develop dysphagia Aspiration pneumonia is the 5th leading

cause of death in the elderly and the most common cause of death in persons with severe dementia.

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Traditional indirect or direct treatments for dysphagia include:

Oral motor exercises Hyolaryngeal exercises/Shaker

exercises Mendelsohn maneuver Thermal stimulation

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Traditional indirect or direct treatments for dysphagia

Often difficult to perform with geriatric patients due to co-morbidities such as Alzheimer’s Disease, various severities of CVAs, and Parkinson’s Disease

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Electrical Stimulation Has been used for decades in PT/OT Little is known on how it affects

swallowing physiology It has been proven that Estim can

assist in hyolaryngeal elevation Hypothesized that increase sensory

input to the CNS enhances swallow

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Neuromuscular Electrical Stimulation (NMES) Low current levels activate

superficial sensory nerve endings providing feedback to the peripheral and central nervous systems

Increased current levels (intensity or pulse width) penetrate deeper depolarizing nerve endings to produce a muscular contraction when the peripheral nervous system is intact

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NMES Using NMES to treat dysphagia, due

in part to decreased laryngeal elevation, provides the SLP with another safe and effective treatment option to help patients improve their swallow

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A&P is the key to diagnosing and treating muscles and cranial nerves

What muscles raise the larynx and what muscles depress the larynx?

Where are they located? Where is the hyoid bone? Where is the trachea? Is it a muscle? Where are the carotid arteries?

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3 separate phases of the swallow Oral - Preparatory/Transport Pharyngeal Esophageal

Three phases of the swallow work together to produce a functional swallow.

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Phases of Swallow Any breakdown in a phase can

cause dysphagia From initiation to its end, the

swallow takes 8-20 seconds. This time significantly increases with age.

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Oral Phase Begins at the lips and ends at the base

of the tongue behind the velum Bolus is formed and positioned in the

middle of the tongue Tongue is elevated and retracted to

create a lingual velar seal to avoid posterior bolus leakage

Can be subdivided into:▪ Oral Preparatory phase▪ Oral Transport phase

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Oral Preparatory Phase A voluntary act that precedes the

swallow Converts food from solid to bolus

state Affected by dentition and salivary

gland function Must be in place before the

pharyngeal phase is initiated16

FACT

Aspiration most often occurs during the

pharyngeal phase but can occur due to

oral stage dysfunction

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Oral Preparatory Phase Lips, tongue, mandible, palate, and

cheeks act in concert with salivary flow to grind and manipulate food into a consistency and position for subsequent phases of swallow to take place

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Zygomaticus major and minor move outer part of lips

Buccinator maintains food between teeth

Masseter assists in chewing Obicularis oris is in motion when

pursing lips to accept liquid bolus from a straw

Soft palate elevates as tensor veli palatini, levator veli palatini and musculus uvulae muscles contract

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Oral Transport Phase Begins when the tongue contracts

against the hard palate Normal movement of the anterior

2/3 of the tongue is essential for carrying out the tasks of the oral stage of swallow

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Oral Transport Phase Tongue Muscles - Intrinsic vs.

Extrinsic Intrinsic Tongue Muscles

Primary action is to produce changes in the shape of the tongue during articulation and deglutition (cradling the bolus)

Superior/Inferior Longitudinal Transversus Verticalis

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Oral Transport Phase Extrinsic Tongue Muscles:

Genioglossus – protracts and depresses tongue

Hyoglossus – depresses tongue Styloglossus – retracts and elevates

tongue Palatoglossus – elevates tongue

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Oral Transport Phase Musculature

Originates along the mental spine, hyoid bone, styloid process, and soft palate respectively; insert into other extrinsic or intrinsic tongue muscles

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FACT

The tongue provides a supplemental role as it provides

anchoring during hyoid bone elevation and upper esophageal

sphincter (UES) opening. It is connected to the hyoid bone,

pharynx, and epiglottis26

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Swallowing Problem Muscle Group Cranial Nerve

Acceptance Orbicularis Oris CN VII

Anterior loss Orbicularis Oris CN VII

Oral scatter or pocketing

Buccinator and intrinsic and extrinsic lingual

muscles

CN VII, IX, XII

Anterior-posterior propulsion

Intrinsic and extrinsic lingual muscles –

Hyoglossus, Genioglossus

CN XII

Mastication Masseter, Pterygoids, and Temporalis

CN V

Cranial Nerves (see booklet on how to test) V : Trigeminal VII : Facial IX : Glossopharyngeal X : Vagus XI : Accessory XII : Hypoglossus

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Pharyngeal Phase Shortest but most complex phase Requires 1-2 seconds to complete –

does not vary with consistency of food, age, or gender

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Pharyngeal Phase Involves highly cortical centers as

well as brainstem centers including CN V, IX, X, XI, and XII

Involuntary, with 90% occurring during expiration

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Pharyngeal Phase Triggered by glossopharyngeal nerve when

bolus encroaches on palatoglossal arch.

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Pharyngeal Phase Additional factors may be

responsible for initiation of swallow:▪ May also be triggered late by superior

laryngeal nerve – “delayed swallow reflex” when this occurs

▪ Posterior tongue movement▪ Stimulation of the pharynx

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Pharyngeal Phase Afferent impulses from cranial

nerves reach the brainstem completing a reflex arc affecting the following automatic events:

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Pharyngeal Phase1) Velopharyngeal closure to prevent

reflux2) Specific sequential closure of the

larynx to prevent aspiration; vocal and aryepiglottic fold adduction; retroversion of the epiglottis

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Pharyngeal Phase3) Pharyngeal constrictor contraction

superiorly to inferiorly while the tongue drives the bolus posteriorly

4) Elevation and anterior pull of the larynx and hyoid bone toward base of tongue

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Pharyngeal Phase5) Relaxation of tonically contracted

cricopharyngeus and inferior pharyngeal constrictor muscles allowing passage of bolus into esophagus

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Pharyngeal Phase As the true vocal folds adduct a

finite period of apnea occurs during swallow lasting approximately 0.3 – 2.5 sec

Deglutition occurs most often during expiration

Can lead to fatigue during the meal and consequent risks of laryngeal penetration and aspiration

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Pharyngeal Phase Following closure of larynx, pharyngeal

peristalsis by contraction of superior, middle and inferior pharyngeal constrictor muscles, then laryngeal elevation takes place.

Laryngeal elevation takes places because the hyoid bone and tongue base move anteriorly and superiorly secondary to contraction of the anterior digastric, mylohyoid, geniohyoid, and stylohyoid muscles.

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Suprahyoids (sling muscles)LARYNGEAL ELEVATORS Digastrics – anterior – elevates/protracts

hyoid, assists with jaw depression Mylohyoid – elevates/protracts hyoid Geniohyoid – depresses jaw,

elevates/protracts hyoid Stylohyoid – elevates/retracts hyoid

Located in the submental area of the submandibular triangle.

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Pharyngeal Phase The first movement of the epiglottis

occurs synchronously with the elevation of the larynx.

Epiglottis acts to anatomically direct food bolus laterally toward the UES, as well as assisting in airway protection

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Pharyngeal Phase The anterior and superior

movement of the larynx combined with the contraction of the middle and inferior constrictor muscles strips the bolus inferiorly ushering in the final portion of the pharyngeal phase – entry of the bolus into the cervical esophagus

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Pharyngeal Phase Studies have shown that PES

relaxation takes place during elevation of the hyoid and larynx and reaches its most complete relaxation at their apex of elevation

The following table shows common swallowing problems in the pharyngeal phase along with associated muscle groups and cranial nerves:

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Swallowing Problem Muscle Group Cranial Nerve

Poor velopharyngeal seal

Decreased closure of the larynx

Weak contraction -pharyngeal constrictors

Tensor Veli Palatini, Levator Veli Palatini, Musculus Uvulae

Post. and Lat. Cricoarytenoids, Transverse Arytenoid

Superior, Middle, and Inferior Pharyngeal Constrictors

CN V, XI

CN IX, X

CN IX, X

Decreased ant/superior elevation - hyolaryngeal complex

Anterior Digastric, Mylohyoid, Geniohyoid

CN V, XII

Difficulty relaxing the cricopharyngeus

Inferior Pharyngeal Constrictor, Cricopharyngeus, Upper Esophageal Musculature

CN IX , X

Esophageal Phase Involuntary action, involves

rhythmic contractions Transit time can increase

significantly with age Transit time range is from 6 – 18

seconds to clear solids

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Esophageal Phase Cricopharyngeal and inferior

pharyngeal constrictor muscles relax allowing the bolus to pass into the upper esophagus.

The bolus passage triggers relaxation of the UES/PES to allow passage via peristaltic contractions

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UES/PES Function: Protects pharynx by preventing

reflux Prevents air entering the

gastrointestinal tract during normal respirations

Relaxes completely to allow gas to exit or when vomiting occurs

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UES/PES Dysfunction may occur secondary to: Reduced laryngeal elevation Abnormal cricopharyngeal

contraction And/or inflammation as a result of

GERD

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Esophageal Phase The upper and lower esophageal

sphincters elongate/relax as much as needed. The LES allows the bolus to enter the stomach.

The following table shows common swallowing problems in the esophageal phase along with associated muscles and cranial nerves:

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Swallowing Problem Muscle Group Cranial Nerve

Failure of opening the UES

Cricopharyngeus CN IX, X

Decreased anterior superior elevation of

the hyolaryngeal complex

Anterior Digastric, Mylohyoid,Geniohyoid

CN V, XII

Poor lingual pressure to drive the bolus through the UES

Intrinsic and extrinsic lingual muscles –

Hyoglossus, Genioglossus

CN XII

Swallow Reflex Term is deceptive in that the swallow is an elicited response requiring both sensory and motor information to initiate the swallow reflex.

One muscle and/or one nerve with impairment can affect the normal swallow function.

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The swallow reflex is NOT a “no brainer”. The brain stem is involved. A typical reflex arc is a “no brainer”.

Information travels to the spinal cord and returns to the limbs.

Normal swallow is a dynamic activity that is dependent on both conscious, volitional cortical action, and reflexive subcortical neuromuscular patterns.

Two reasons we swallow▪ Maintenance – to manage own secretions▪ Swallow food or liquid

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Swallow reflex arc affects: Velopharyngeal closure Laryngeal closure (specific

sequence); vocal and aryepiglottic fold adduction and epiglottis retroversion

Pharyngeal constrictor contraction Laryngeal/hyoid bone elevation and

anterior pull Cricopharyngeus/inferior pharyngeal

constrictor muscles53

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Displacement of the food bolus into the pharynx by the tongue initiates swallow.

Relaxation of the cricopharyngeal muscle (the physiological upper esophageal sphincter) permits movement of the food bolus into the proximal esophagus.

Assessment forms the basis of developing management strategies

Rarely does one form of assessment provide complete diagnostic information

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Bedside Swallowing Evaluation (BSE) 1st step in a clinical assessment Head and neck examination Cranial nerve examination Oral phase – observe chewing Clinical signs of pharyngeal dysphagia Determines need for instrumental evaluation,

and specific diagnostic questions to be answered by instrumental evaluation

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Fiberoptic Endoscopic Evaluation of Swallowing (FEES) Evaluates pharyngeal stage of swallow;

oral phases only evaluated indirectly; no esophageal phase evaluation

Mildly invasive Limited to events immediately before

swallow and after the swallow event

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Modified Barium Swallow Study (MBSS) Assesses oral, pharyngeal,

esophageal phases Aspiration cannot be confirmed or

ruled out without MBSS Approximately 40% of patients

aspirating on MBSS were not identified as aspirators during BSE

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MBSS Allows visualization of pharyngeal

phase while compensatory strategies are tested

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There is a 3.7 times greater likelihood that aspiration is occurring with dysphagia if hyoid movement is reduced during swallow.

Reduced elevation of the larynx and pharynx is usually due to reduced hyoid bone elevation.

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The muscles of the floor, specifically the paired Mylohyoid, Geniohyoid, and Anterior Belly of the Digastric are responsible for the anterior and superior movement of the Hyoid.

This motion plays a crucial part in moving the larynx forward reducing risk of aspiration.

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Suprahyoids - Laryngeal Elevators (sling muscles) Ant. Digastric – elevates/protracts hyoid Post. Digastric – elevates/retracts hyoid

together assist with mandible depression Mylohyoid – elevates/protracts the hyoid Geniohyoid – elevates/protracts hyoid,

depresses mandible Stylohyoid – elevates/retracts hyoid

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Infrahyoids - Laryngeal Depressors (strap muscles) Omohyoid – depresses hyoid Sternohyoid – depresses hyoid Sternothyroid – depresses thyroid Thyrohyoid – shortens the distance

between the thyroid and hyoid bone

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Hyoid bone moves an average of 9-12 mm anteriorly and 11-12 mm superiorly

Duration of hyoid movement is influenced by bolus size, however extent of displacement is not

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Reduced laryngeal elevation is strongly associated with aspiration

Superior movement of the larynx helps to bring the airway safely away from the path of the bolus

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Manually lifting the larynxProlong laryngeal elevationLimited benefit with those with

severe cognitive deficits. NMES with proper submandibular

placement can produce a involuntary pseudo Mendelsohn Maneuver

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Patients with reduced epiglottic function are 4.4 times more likely to aspirate

Epiglottis is cartilage, not muscle Does not have independent movement Moves passively by force of muscles

attached to it – pulls tip posteriorly, giving epiglottis a horizontal tilt, bending from the top down

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Primary attachments at top/sides is hyoid bone

Primary attachments at bottom is thyroid cartilage ligament

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The first epiglottis movement occurs synchronously with laryngeal elevation – thickening the base of the epiglottis and assisting with closure of the laryngeal vestibule

Due to anterior movement of hyoid and approximation of thyroid cartilage to the hyoid bone

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4 types of impaired epiglottic function: Rigid/absent –

calcification/osteophytes Incomplete inversion or lowering –

nasogastric tubes Prolonged inversion or lowering –

exaggerated curvature of epiglottis Base of tongue approximation of

epiglottis – rests against tongue base, eliminates vallecular space

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Compensatory Strategies Designed to redirect or improve

food flow, eliminate symptoms such as aspiration

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Therapy Procedures Designed to change swallow

physiology (in contrast to compensatory strategies)

Improve range of motion of oropharyngeal structures

Improve sensory integration Take voluntary control of timing/

coordination of orophargyngeal movements

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Indirect Therapy Exercise Programs or swallow

saliva, but no food/liquid givenDirect Therapy

Practice swallow techniques with small amount of food/liquid

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Postural Techniques NO single posture improves

swallowing in all patients. Correct physiologic/anatomic

disorder must be identified in order to implement the correct compensatory posture(s).

Changing the head or body posture can be effective in eliminating aspiration 50% of the time.

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Postural Techniques Some patients can’t use postural

strategies because of head stabilization devices or other physical/cognitive constraints.

Use of postural techniques is generally temporary.

Patients use them until swallow recovers or other treatment procedures which improve oropharyngeal motor function take effect

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Muscle tissue – highly specialized fibers that generate a force for contraction

Nerves connect the spinal cord to the muscle

Neuromuscular junction – spot where nerve meets muscle

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Electrical signal (nerve impulse) crosses neuromuscular junction – transmitted deep inside muscle fibers

Signal stimulates flow of calcium – causes thick and thin myofilaments to slide across each other – causing muscle to shorten, generating a force

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Global view of a neuromuscular junction:

1. Nerve2. Neuromuscular junction3. Muscle fiber4. Myofibril with myofilaments inside

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Billions of myofilaments in muscle shorten all at once to cause contraction of entire muscle fiber

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Muscle fibers can be grouped according to the kind of tissue they are found in:

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Muscle Type Location

Contraction Control

Cardiac In the walls of the heart Involuntary

Smooth In the walls of hollow internal structures (e.g.,

bladder)

Usually Involuntary

Skeletal At the attachment to bones

Voluntary

Skeletal muscle – further divided into 2 basic types: Type I (slow-twitch fibers) –

primarily use cellular respiration, relatively high endurance – contain high levels of mitochondria (powerhouse of the cell) and myoglobin (oxygen storage) – responsible for red color of tissue

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Type II (fast-twitch fibers) – relatively low endurance – typically used for short bursts of strength – cannot not sustain contractions for significant lengths of time▪ Further divided into: Types IIa and IIb

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Type II (fast-twitch) Type IIa – appear red due to high

content of myoglobin and mitochondria

Type IIb – fastest firing, most powerful, but tire the fastest – appear white due to low oxygen demand

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Fiber Type Type I Type IIa Type IIb

Contraction time Slow Fast Very Fast

Endurance High Intermediate Low

Fatigue Slow Intermediate Fast

Power Low High Very High

Motor neuron size Small, Narrow

Large Very Large

Function Static, Postural

Dynamic Dynamic, explosive

Energy Source Oxygen Oxygen, Glycogen

Glycogen

Color Red Red White

Most skeletal muscles contain a mixture of all 3 types of fibers – proportion depends on “usual” action of the muscle Posterior neck/back – postural

muscles – higher proportion of type I Anterior/lateral neck – rotating,

flexing, nodding – higher proportion of type II

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Several swallowing muscles have: higher proportion of type II fibers -

▪ Anterior digastric▪ Mylohyoid▪ Upper pharyngeal constrictors

higher proportion of type I fibers – ▪ Cricopharyngeus

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During contraction muscle fibers relay message to each other If a weak contraction is needed,

only type I fibers are activated If a maximal contraction is needed,

then type II fibers are activated as well

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Consequently type I fibers receive the primary benefit from low intensity exercises found early in rehabilitation

The larger, type II fibers can only be exercised when dynamic activity calls on their recruitment – missed early on in rehab, this quickly leads to disuse atrophy of these fibers/muscles

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Recruitment pattern with estim is reverse of that through exercise Type IIb fibers are first to contract as

the motor neuron for these fibers is larger and has a lower depolarization threshold

Type IIb fibers therefore respond sooner to electrical current when exposed

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Estim and active exercise together - ideal way to treat swallowing musculature, due to high overall percentage of type II fibers present in muscles

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Process by which electrical stimulation works has been well documented and studies

Extrinsic muscles of the swallowing mechanism bear no histological difference to any other skeletal muscles typically treated by PT and OT.

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46 AD Torpedo fish were used to treat pain Late 1700’s Galvani stimulates frog muscle

with electrical charge of metal First identified research of motor points

was in the 1800’s Electrical Stimulation potentials

documented in articles as early as 1951 to prevent disuse atrophy Orborne, SL, 1951 on The Retardation of

Atrophy in Man by E-Stim of Muscles.

Current practices?93

Brief history of Neuromuscular Electrical Stimulation (NMES) or “E-Stim.” Currently an FDA approved modality used

primarily by Physical/Occupational Therapists and now entering the field of Speech Pathology

Stimulation requires an intact peripheral nerve

Treatment goals: strengthening and recovery of motor control

Use requires extended education in the area of electrotherapy

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Prevent disuse atrophyIncrease range of motionRe-educating of muscle functionTemporarily decrease spasticityServe as an electrical orthosisIncrease local blood circulation

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Neuromuscular Electrical Stimulation (NMES) is the use of electricity to stimulate the nerves that correspond to a targeted muscle or group of muscles and cause it to contract. This occurs when negatively charged subatomic particles, called electrons, flow from the negative to the positive pole in tissue, via transcutaneous electrodes for therapeutic benefit. It requires an intact peripheral nerve. This includes the health and integrity of the cell body, axon, myelin sheath, nerve and muscle.

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Patients with any implanted electronic device e.g. cardiac pacemakers, spinal cord stimulators

Over neoplasm or infectionPlaces where active motion is contra-indicated

(i.e., fractures, anastomosis or fusions)Use during pregnancyCarotid Sinus Reflex Sensitivity

Do Not Stim Over Carotid Sinuses. Particularly in patients with a known sensitivity to carotid sinus reflux, due to blood pressure changes.

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Patients with suspected or diagnosed epilepsy or seizure disorder

Stimulation on the anterior neck Skin with absent or diminished sensation History of Laryngeal Spasm

Stimulation should not be applied over the anterior neck. Severe spasm of the laryngeal and pharyngeal muscles may occur, causing difficulty breathing.

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What are you doing? DYSPHAGIA TREATMENT – 92526 CMS stipulates SLP should bill this for

treatment of swallowing dysfunction and/or oral function of feeding.

Denials for 97110 and 97112▪ G0283 - Electrical Stim (unattended), 97032 (face to

face) Payor denial prompted CMS to review coding

issues. CMS does not support the use of physical

medicine codes.

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Not a timed code, it is a service codeTreatment of swallowing dysfunction

and/or oral function for feeding.Must provide treatment exercises to

make it substantial and avoid denials if reviewed.

No modality should be used in isolation

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You are doing a speech treatment to improve swallowing.

Goals are the same as tx with the Mendelsohn maneuver, hyolaryngeal exercises etc. (see example of goals in booklet)

You are achieving laryngeal elevation, improved timing of the swallow, increasing PO etc.

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Always indicate your proof of disorder (i.e. decreased laryngeal elevation) which includes evaluation of the pharyngeal phase, which would include an MBSS.

Techniques utilized (Mendelsohn, Supraglottic swallow, etc.) must be considered appropriate based on patients documented condition.

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Ethics Individuals should only practice in areas

which they are competent based on their education, training, and expertise. (Principles of Ethics II Rule B, ASHA Code of Ethics)

Rule A insists that clinicians provide all service “competently and admonishes against misrepresenting one’s competence.

Rule G states individuals shall evaluate effectiveness of services rendered.

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Electrical Stimulation for Swallowing:In early 2004, speech-language pathologists, the California Physical Therapy Association, and manufacturers of electrical, stimulating devices asked about the licensing authority for speech-language pathologists to use electrical stimulation applied to the surface of the anterior neck to treat swallowing disorders. The Board discussed the issue at its public meetings during which device manufactures provided background on the specific devices cleared by the Federal Drug Administration. Licensees also discussed their therapy successes in applying electrical stimulation to the skin of a patient with swallowing disorders. Further, the Board consulted with otolaryngologists about the research and application of this new therapy, and sought the advice of legal counsel whether existing scope of practice laws and regulations permit licensed practitioners to use an electrical instrument as a therapeutic intervention to treat swallowing disorders.

Although legal counsel concluded that the law does provide the authority for speech-language pathology licensees to use electrical stimulation to treat swallowing disorders, counsel concluded that such authority does not imply that all licensed practitioners are competent to provide it. Concurrent provisions relating to the professional conduct of a licensees enforces that "incompetence in the practice of speech-language pathology which has endangered or is likely to endanger the health, welfare, or safety of the public" constitutes unprofessional conduct and is grounds for formal discipline. As such, licensed professionals should not engage in providing electrical stimulation therapy for swallowing unless they are adequately trained and competent in its application, are aware of the potential risks, and are able to respond to any adverse reaction that may occur.

Finally, the Board also expressed concern regarding the deficiency of peer-reviewed research to support the efficacy of using electrical stimulation to treat swallowing disorders. Even though electrical stimulation may be within the scope of practice of a speech-language pathologist, the Board is unclear whether it is a beneficial therapy that provides significant, sustained relief to affected members of the public.

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Permission to reproduce the illustrations from Dr. Wesley Norman was granted to AMPCARE, LLC.

Copyright© 1999 by Wesley Norman, PhD, DSc

http://www.wesnorman.com

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Permission for AMPCARE, LLC to reproduce these illustrations from Grays Anatomy, Vol. 36, 1980, Williams et al granted by Elsevier Ltd, The Netherlands.

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