Perspectives on Swallowing and Swallowing Disorders (Dysphagia)

Editor's Corner

Davis, L. — Wed, 10 Mar 2010 08:25:27 PST

Role of Neurostimulation and Neuroplasticity in the Rehabilitation of Dysphagia After Stroke

Hamdy, S. — Wed, 10 Mar 2010 08:25:27 PST

Swallowing problems are common after brain injury, and can affect as many as 50% of patients in the period immediately after stroke. In some cases this can lead to serious morbidity, in particular malnutrition and pulmonary aspiration. Despite this, swallowing therapies remain controversial, with limited evidence base and little in the way of objective scientific criteria. Moreover, swallowing can recover in some patients to a safe level within weeks, making it an interesting model for understanding brain recovery and cortical plasticity. A better understanding of these adaptive processes as seen in spontaneous recovery therefore may help in developing therapeutic interventions that can drive plasticity and so encourage the recovery process. In this article, I will examine present knowledge about the recovery mechanisms for swallowing after brain injury, particularly from investigations with Transcranial Magnetic Stimulation, and explore what aspects are important for compensating for recovery after damage. In addition, I will describe novel approaches to swallowing therapy, based on objective neurophysiological models that may be useful in speeding up the process of recovery and encouraging cortical plasticity that may form the basis for future clinical trials of dysphagia after brain injury.

Plasticity in the Human Motor System

Rothwell, J. C — Wed, 10 Mar 2010 08:25:27 PST

It is well recognized that the number and effectiveness of synapses in the adult brain changes in response to learning and that similar processes contribute to the restoration of function after central nervous system damage. It is possible to use non-invasive methods of brain stimulation in humans (transcranial magnetic stimulation, TMS; or transcranial direct current stimulation, TDCS) to study and even manipulate these processes. Initial studies now are underway to test whether modification of synaptic plasticity by neurostimulation can improve recovery of motor function in patients after stroke.

Transient Cortical Stimulation To Alter Swallowing Physiology

Humbert, I. A. — Wed, 10 Mar 2010 08:25:27 PST

Older adults are disproportionately affected by swallowing impairment, or dysphagia, a condition that can lead to increased morbidity and death. Delayed initiation of swallowing is a common and devastating pathophysiology of neurogenic dysphagia, and also is experienced by healthy older adults, making functional swallowing less safe. It is still not known if differences in activation of the cortex (primary sensory motor region) are responsible for delays in swallowing initiation, or if it is the consequence of advancing age. The goals of this proposal are to understand the functional role of the primary sensory-motor cortex on swallowing initiation and to characterize the effect of aging on swallowing initiation with transient cortical disruption. The overall hypothesis is that transient disruption of the primary sensory-motor cortex will produce measurable delays in swallowing initiation in young and old adults, but older adults will have more pronounced deficits. This investigation will determine whether cortical areas are involved in initiating swallowing as well as the importance of timing on this function.

Event-Related Potentials and the Swallow System

Pitts, T., Wheeler-Hegland, K., Davenport, P. — Wed, 10 Mar 2010 08:25:27 PST

Electroencephalography (EEG) is a methodology that offers information on the processing of afferent information to the cortex and does not require a motor response. This method could be highly beneficial to researchers interested in the upper airway, specifically portions of the upper airway which initiate or modify reflexes (i.e. swallowing, cough, gag, etc). The following is a short description of the methodology, signal processing, signal interpretation, and potential impact on swallowing research.

Strengthening Connections Between University Classrooms and Clinical Settings

Bailey, R. L. — Wed, 10 Mar 2010 08:25:27 PST

The continued evolution of evidence-based practice in dysphagia is enhanced when connections between university classrooms and clinical settings are strengthened. Suggestions for facilitating improved lines of communication and interaction between these two important entities are provided.