Volitional Swallowing in Stroke Patients With Chronic Dysphagia

Stroke Clinical Trial

Official title: Induction of Volitional Swallowing in Chronic Dysphagia Post Stroke: A Novel Mechanism-Based Intervention

Status Completed

Clinical Trial Summary

This study will compare several techniques designed to improve the ability to swallow in stroke patients with chronic dysphagia (difficulty swallowing).

Healthy volunteers 20 to 60 years of age and people 20 to 90 years of age who have had a stroke resulting in swallowing problems may be eligible for this study. Volunteers are screened with a medical history, physical examination, and urine test for women to rule out pregnancy. Stroke patients are screened additionally with a chest x-ray, physical examination, cognitive screening, swallowing questionnaires, nasoendoscopy (examination of the nasal passages in the back of the throat using a lighted telescopic instrument) and FEESST (passage of a thin, flexible telescope through the nose to the voice box), videofluoroscopy (x-ray of the head and neck during swallowing) and button press training (learning how to press a button on a table in coordination with swallowing).

All participants undergo the following procedures:

• Transcranial magnetic stimulation (TMS): A metal coil is placed on the head and sends a pulse of energy to the brain through the scalp. The muscle response to the pulse is recorded from the muscles in the throat that are associated with swallowing.

• Electromyography: A needle is used to insert tiny wires in specific muscles of the throat to record the muscle response to the TMS pulses.

• Magnetic resonance imaging (MRI): During brain MRI scanning, subjects lie quietly and images of the brain are taken.

In addition to the above tests, stroke patients undergo the following:

• Water test: The subject swallows a small amount of water and the number of times required to clear the throat or cough is counted. This test is repeated five times.

• Experimental training. Subjects have a total of 12 60-minute training sessions, one session a day for up to 5 sessions a week.

• Button press training: The subject swallows small amounts of water. A device placed on the throat senses when swallowing occurs. The subject learns how to coordinate pressing a button on a table in coordination with swallowing.

• Vibrotactile stimulator training: A device that uses a buzzing vibration is placed on the throat at times during the swallowing training.

• Transcranial direct current stimulation (tDCS): Wires attached to sponge electrodes are placed on the scalp and over the eye. Small electric currents are delivered to areas of the brain involved with swallowing. This is done at times during the swallowing training.

Participants may receive one of several combinations of training approaches; all receive the volitional (button-press) training. Within 5 days of completing training, subjects repeat the tests. TMS, MRI, MEG and x-ray study of swallowing function are also repeated to see if any changes have occurred in the brain or in the ability to swallow after training. Patients are contacted by telephone and in writing 3 and 6 months after training for follow-up on their swallowing status and oral intake.

Clinical Trial Description

Objectives:

Chronic pharyngeal dysphagia is a life threatening disorder following brain injury. Repeated occurrences of aspiration pneumonia result in expensive hospital stays and reduced survival. The purpose of this investigation is to compare two novel training methods: 1) training to initiate swallowing while pressing a switch; 2) training to initiate swallowing while pressing a switch with coincident peripheral vibrotactile stimulation.

Some preliminary studies will be conducted in healthy volunteers to determine the feasibility of using near infrared spectroscopy (fNIRS) for measuring change in brain activation for swallowing before and after treatment and to determine the physiological effects of direct current stimulation on brain activation for swallowing, during sensory stimulation and at rest.

Patients will be randomly assigned to one of two training groups and the results of 12 training sessions will be contrasted using blinded assessment. The hypothesis being tested is that training methods involving simultaneous peripheral-sensory stimulation will reduce the risk of aspiration or penetration during swallowing in patients with chronic pharyngeal dysphagia post brain injury.

Two additional questions address the neural mechanisms involved in the training effects. To determine whether changes occur in cortical control of the hyo-laryngeal musculature involved in swallowing, patients will also be studied before and after training using transcranial magnetic stimulation to assess muscle responses to cortical stimulation. Finally, to determine if training effects are related to changes in cortical neuroplasticity, we will use near infrared spectroscopy to measure functional change in brain activation in M1, for swallowing to determine if cortical control is enhanced in the different training groups.

Study Population:

Healthy volunteers and patients with chronic pharyngeal dysphagia following brain injury will be studied.

Design:

Healthy control subjects will be assessed first in three studies:

1. A study comparing the effects of air puff versus vibrotactile stimulation on inducing swallowing

2. A study of the transcranial magnetic stimulation to elicit responses from pharyngeal and submental muscles

3. A study using near infrared spectroscopy to examine brain activation responses to sensory stimulation, brain laterality for swallowing and the effects of transcranial direct current stimulation (tDCS) on brain responses to sensory stimulation and brain activation for swallowing.

Patients with chronic pharyngeal dysphagia following brain injury will participate in a clinical trial evaluating swallowing motor retraining with and without sensory stimulation. This study will be a randomized, blinded Phase 2 clinical trial in which patients will be assigned to two training conditions: training with sham sensory stimulation and training with vibrotactile sensory stimulation.

A non-invasive, external vibrotactile stimulator on the throat will provide external sensory stimulation. Pre-training testing, training sessions, and post-training testing will be provided in up to 20 visits for each subject.

Outcome Measures:

The primary outcome variables will be measures of swallowing function before and after training and at 3 and 6 months post training. These will include the NIH Swallowing Safety Scale scored from masked videofluoroscopy recordings and the Water Test, a non-invasive assessment of swallowing. Both will be scored by speech pathologists blinded to patient training group identity or condition before or after training.

To assess the relationship of improvements in training with changes in neuronal function, transcranial magnetic stimulation with surface electromyography recordings will be used to assess changes in corticobulbar conduction following training.

To assess whether functional activation within the brain (particularly in the region of M1) is related to improvement in swallowing following each type of training, near infrared spectroscopy NIRS will be used to examine blood oxygenation level dependent changes in brain function for swallowing following training. All outcome measures will be scored without knowledge of training group or condition (pre vs. post training or training group). ;

Related Conditions & MeSH terms

• Deglutition Disorders
• Dysphagia
• Stroke

• NCT number: NCT00306501
• Study type: Interventional
• Source: National Institutes of Health Clinical Center (CC)
• Status: Completed
• Phase: Phase 2
• Start date: March 17, 2006
• Completion date: December 16, 2009