Introduction
Acquired brain injury (ABI) can occur from a traumatic (i.e., falls,
assaults, injuries, motor vehicle accidents) or non-traumatic (tumors,
congenital defects, aneurysm, etc.) etiology (1, 2). Traditionally,
ischemic or hemorrhagic strokes have not been included in the definition
of ABI given their unique pathophysiology and outcomes. Following an
ABI, patients may present with a number of impairments including
dysphagia, a common and challenging problem affecting the rehabilitation
process. Dysphagia or oropharyngeal dysphagia is characterized by
abnormal function or structural deficit of the oral cavity, pharynx,
larynx, or esophagus as a result of damage to motor and sensory
coordinating pathways (3). Delayed pharyngeal movement and failure to
coordinate the passage of food into the esophagus, while also protecting
the airway or trachea, can result in aspiration of food and liquids.
While many patients with dysphagia do not aspirate, the risk of
aspiration rises with the severity of the dysphagia.
Severity of dysphagia is typically related to the severity of the
underlying brain lesion. Moderate and severe ABIs result in high rates
of dysphagia (4, 5); dysphagia is rare in those with mild ABI (6).
Overall, prevalence rates of dysphagia range 27-30% in patients with
traumatic brain injury (TBI) (7). Dysphagia can cause severe and
sometimes life-threatening problems largely due to airway obstruction,
aspiration, and the risk of pneumonia and sepsis (8). Additionally, poor
nutritional intake with resultant malnutrition and dehydration can
present later (3). Nutritional status is important after ABI as it
impacts both short and long-term recovery. Malnutrition and dehydration
have been shown to significantly extend a patient’s acute care hospital
stay, 1.6 times longer compared to non-malnourished, and impact
functional independence during rehabilitation (9-11). The consequences
of dysphagia can be mitigated if this condition is diagnosed and managed
promptly (12). Generally, Speech Language Pathologists assess and apply
interventions to reduce the risk of aspiration and improve swallowing
function (6). While the most common interventions are dietary-related
(food texture modification), compensatory and rehabilitative strategies
are also used.
Controversy remains regarding the effectiveness of dysphagia
interventions in neurological populations. Research often focuses on
either a single intervention type or on a specific research question,
not reflecting the significant heterogeneity of data (13). The majority
of dysphagia studies examine the stroke population, or a mixed
populations with little attention to the underlying etiology (14, 15).
Since deficits are similar between ABI and stroke (16), often ABI
rehabilitation therapists “borrow” strategies from the stroke
rehabilitation literature. Unfortunately, differences in underlying
pathophysiology of ABI may warrant the use of distinct approaches (17).
While stroke leads to focal brain damage, TBI lesions may be a complex
mixture of focal injury and diffuse axonal injury (18). In fact, there
is a paucity of ABI-specific literature for dysphagia interventions.
Reviewing ABI-specific studies are necessary to better address the
rehabilitation needs of these patients. To investigate the available
literature and identify existing interventions for dysphagia
rehabilitation, we sought to conduct scoping review of individuals with
moderate to severe ABI during the acute and chronic phases of recovery.