A Comparison of an Implanted Neuroprosthesis With Sensory Training for Improving Airway Protection in Chronic Dysphagia

A Comparison of an Implanted Neuroprosthesis With Sensory Training for Improving Airway Protection in Chronic Dysphagia

This study will compare an implant with the technique of sensory training to determine which method may improve the ability to swallow and reduce the risk of choking. Many people with a brain injury or neurological disorders experience difficulty in swallowing. Past studies have shown that an electrical pulse applied to muscles or an increase in sensory stimulation to the throat can help.

Patients ages 18 to 90 who have had a brain injury or neurological disorder and who have had trouble swallowing for 6 months or longer may be eligible for this study. Patients will undergo a physical examination, pregnancy test, and exam by a throat and speech physician. Fiber-optic endoscopic evaluation of swallowing with sensory testing involves a flexible tube passed through the nose to the back of the throat to allow observation of the voice box. Videofluoroscopy, an X-ray of the head and neck, will be done while patients swallow. Patients experiencing trouble with the upper esophagus may undergo additional procedures, including manometry to measure pressure changes in the back of the throat, and reevaluation through the fiber-optic tube. Patients in this study will have a magnetic resonance imaging (MRI) scan, which uses a strong magnetic field to obtain images of the body. Patients will lie on a table that slides into the enclosed tunnel of the scanner. The scan will take 20 to 25 minutes.

Patients will be assigned randomly to one of two groups: the intramuscular group, to have a stimulation device implanted in the neck, and the vibrotactile group, to receive a vibrotactile stimulator. All patients will have 10 training sessions with their devices, plus follow-up. Those patients in the first group will undergo surgery, under general anesthesia, for the implant. Three weeks following the implant procedure, patients will come to NIH to have the stimulator turned on and programmed and to learn how to use the device. Those patients in the second group will have about 2 to 3 weeks of training in using a vibrotactile device, and then they will take it home to use. All patients will return to NIH at 3 months to ensure proper use of the devices, and they will visit for follow-up at 6 months and 12 months for tests and questionnaires.

...

Objective: To determine if an implanted neuroprosthesis improves airway protection for swallowing in chronic pharyngeal dysphagia to a greater degree than sensory training. The implanted neuroprosthesis will provide intramuscular stimulation to as many as 8 hyo-laryngeal muscles. Stimulation will be coincident with a button press initiation under patient control while eating or at regular intervals for saliva swallows during the day and/or at night. Sensory training will include vibrotactile stimulation to the neck coincident with swallowing under patient control to assist with swallowing while eating or for saliva swallows during the day.

Study population: Persons with chronic (greater than 6 months) dysphagia with risk of aspiration secondary to neurological injury, stroke or chronic neurological disease who currently require enteric feeding or severe dietary restrictions because of risk of aspiration.

Design: A Phase 2 clinical trial with random assignment between two treatment groups with blinded assessment of treatment outcome. Both treatment groups will undergo 2 weeks of device training with a speech pathologist. The implant group will undergo training starting 3 weeks after implantation. They will receive prescriptive training when the levels of muscles stimulation will be established for swallowing. Patients will be trained to press a switch to control the stimulation while they are swallowing. The sensory training group will receive the same amount of training to provide sensory stimulation coincident with attempting to swallow.

Outcome measures: Blinded assessment of risk of aspiration on videofluoroscopy using the NIH Swallowing Safety Scale, and patient administration of the Functional Oral Intake Scale (FOIS) for Dysphagia and the Swallowing Quality of Life Outcomes Tool (SWAL_QOL) prior to treatment and at 3, 6, 9, and 12 months following treatment. Patient administration of the FOIS and SWAL_QOL at 24-months.

• INCLUSION CRITERIA:

• Inclusive ages of 18 to 90.

• History of cerebral vascular accident (CVA), brain injury or chronic neurological disease such as Parkinson disease or multiple sclerosis or history of chemoradiation for treatment of head and neck cancer resulting in chronic dysphagia.

• Evidence of pharyngeal phase dysphagia that places the patient at risk for aspiration. Risk for aspiration or frank aspiration will be based on the medical history and evidence from a swallowing study. Absence of aspiration is not cause for exclusion if the risk for aspiration is deemed present due to impaired pharyngeal phase of swallowing as judged by an expert experienced in the evaluation of dysphagia. The patient may demonstrate evidence of aspiration or the risk for aspiration on any consistency, perhaps secondary to pharyngeal retention. Aspiration is defined as passage of food, liquid, or secretions into the trachea below the level of the vocal folds. Impaired pharyngeal phase of swallowing may be evidenced by pharyngeal delay, reduced hyolaryngeal elevation, reduced laryngeal closure, and reduced pharyngeal clearance of the bolus. Signs of pharyngeal delay include temporary pooling of the material in the vallecula with eventual spill over into the pyriform sinuses. Reduced hyolaryngeal elevation will be identified when the larynx is not protected by epiglottal lowering and remains opens to the bolus during a swallow on videoendoscopy. Reduced pharyngeal clearance can be seen during videoendoscopy when the bolus remains in the vallecula and/or pyriform sinuses.

• Other criteria for inclusion for subjects who do not meet the criteria of having aspiration on videofluoroscopy because of the limited number of swallows necessitated by radiation exposure, or who are noncompliant with their NPO status are:

  1. Not all of the bolus can enter the esophagus because of reduced opening of the upper esophageal sphincter, as a result there is pooling of the bolus in the pyriform sinuses which will spill over into the airway.
  2. Many patients who have had dysphagia for several years, have learned to cough up the bolus from the hypopharynx and spit it out, thus preventing aspiration but are continuing to be unable to ingest food or liquid. This is how they manage their accumulation of saliva by spitting in a cup throughout the day. In this way although they cannot swallow they do not aspirate on examination; rather they clear back up any remaining bolus up into their mouths.
  3. Other signs of risk of aspiration are the observation of liquid or food remaining in the pyriform sinuses, a wet gurgling sound during phonation indicating that there is pooling at the vocal folds and coughing when the bolus has already entered the trachea on attempts to swallow.

• Duration of Dysphagia for 6 months or more.

• A score of 2 or greater on the NIH Swallowing Safety Scale.

• Participants may have other health problems such as diabetes mellitus, arteriosclerotic coronary vascular disease and a history of smoking. These will not be cause for automatic exclusion, but will be examined on an individual basis by the otolaryngologist in determining the potential risk and benefit to the individual participant.

• Prior history of tracheostomy is not a cause for exclusion. Patients currently with a tracheostomy will be excluded.

• Restricted oral intake. Patients should demonstrate a current dependence on alternate means of nutrition and hydration (PEG, PEJ); however, PO intake is not cause for exclusion.

• Adequate cognitive skills as demonstrated by a Mini-Mental State Examination (MMSE) score greater than or equal to 23.

• Stable medical status. To determine if a patient has stable medical status prior to admission, the patient will be asked to provide a letter from their physician stating that the patient is medically stable and may participate in the study.

EXCLUSION CRITERIA:

• Subjects with Severe or Very Severe Chronic Obstructive Pulmonary Disorder (COPD). Definition of Severe COPD is an FEV(1)/FVC ratio of less than 70% and an FEV(1) of 30 to less than 50% of predicted. The definition of Very severe COPD is an FEV(1)/FVC ratio of less than 70% and an FEV(1) of less than 30% of predicted. Spirometry will be performed according to the standards of the American Thoracic Society using reference values that include a correction for race.
• HIV positive or immune compromised. This is essential because increased risk of immune reactions to the implantation of a foreign device in patients who are immune compromised. Such patients would be at much greater risk of an infection with implantation of a device. Participation would more likely lead to the need an explanation and a second surgery.
• Patients with a pacemaker, deep brain stimulator or other indwelling electrical device.
• History of rapidly progressive neurodegenerative disorders, such as progressive supranuclear palsy, dementia, peripheral neuropathy, multiple systems atrophy or amyotrophic lateral sclerosis.
• Severe oral phase swallowing deficits, due to loss of tongue control, that prevent bolus retention in the oral cavity.
• No aspiration or risk for aspiration in previous assessment or during preliminary studies.
• An esophageal motility disorder preventing food or liquid from adequately moving through the esophagus into the stomach.
• Pregnant women will be excluded from participation because the study involves radiation exposure.
• Current psychiatric disorder other than depression. Examples of psychiatric disorders to be excluded are: somatoform disorders, conversion disorders, schizophrenia or bipolar disorder.
• Inability to coordinate button press with swallow (as determined during screening).