5.3 Incidence and Natural History of Dysphagia Post ABI
The reported incidence of dysphagia in the brain-injured population varies considerably, due in part to differences in the timing and method of assessment and the initial level of severity. Among patients admitted to a rehabilitation facility Mackay et al. (1999a) estimated the incidence of dysphagia ranged from 25-42%, which is similar to Cherney and Halper (1996) who reported the incidence of swallowing disorders in an acute rehabilitation setting between 27% to 42%. Among patients 12 to 45 years, Field and Weiss (1989) reported a 30% incidence of dysphagia in patients with head injuries admitted to a rehabilitation facility. Ward and Morgan (2001a) have noted that studies reporting on dysphagia frequency in ABI patients in rehabilitation settings vary from 25-78%; the most recent studies report an incidence of 42-65% (see Table 5.2).
Two recent studies conducted by Hansen et al. (2008a, 2008b), concluded that severity of the brain injury, RLA and FIM scores were predicative of who would develop difficulties with swallowing. Individuals with more severe brain injuries and lower RLA and FIM scores, were at higher risk for developing pneumonia post ABI. In addition, many of these patients required more time before they were able to return to an oral diet. In a study of 117 subjects with ABI Hansen et al. (2008) found that, of the 21 individuals who developed pneumonia, 17 were dependent on tube feeding. While the majority (n=12) developed pneumonia only once, some (n=9), developed pneumonia two and three times post injury.
The natural history of dysphagia has not been well studied. Although the incidence of dysphagia is high following ABI, swallowing function most frequently improves over time. Winstein (1983) reported that by time of discharge, 84% of those patients admitted with swallowing problems were eating oral feeds. At follow-up in the outpatient clinic this number increased to 94%. The actual number of patients whose dysphagia had completely resolved and who were consuming regular-textured diets and thin liquids is unknown.
Individual Studies
Table 5.2 The Incidence/Prevalence of Dsyphagia Following ABI
Authors |
Methods |
Outcomes |
|
Halper et al., (1999) |
N=148 Retrospective review of patients consecutively admitted to an acute rehabilitation facility. Patients were admitted an average of 54 days post injury. Dysphagia was identified using the Chewing and Swallowing item on the Rehabilitation Institute of Chicago Functional Assessment Scale (RIC FAS), a 7 point ordinal scale (1=severe impairment, 7=normal) |
96 (65%) were diagnosed with dysphagia. Patients were considered to be dysphagic if they received a RIC FAS score of less than 7. |
|
Mackay et al., (1999b) |
N=54 Prospective evaluation of patients with severe head injury consecutively admitted to an acute trauma centre. Patients were included only if they were sufficiently cognitively intact to enable a VFSS swallowing evaluation. |
33 (61%) of patients demonstrated one or more swallowing impairments on VFSS examination. 22(41%) patients aspirated. The GCS scores of aspirators were lower than for non-aspirators. |
|
Schurr et al., (1999) |
N=47 Retrospective review of patients who had been referred for a swallowing evaluation while an inpatient at a rehabilitation facility for severe TBI. The average GCS score was 8. Patients received a bedside evaluation and those with abnormal findings also received a video flurospoic examination.. |
33 (70%) patients had an abnormal bedside evaluation. 31/32 patients went on to receive a VFSS. (Aspiration was overt in the remaining 2 patients and they received a gastric feeding tube on the basis of the failed bedside evaluation). The VFSS was abnormal in 22/31 (71%) patients. |
|
Cherney and Halper (1996) |
N=189 The incidence of dysphagia was collected on adult head-injured patients at the Rehabilitation Institute of Chicago (RIC) over an 18-month period. |
Approximately 26% of adult head injured patients (49 of 189) had dysphagia on admission. Of the 49 dysphagic head-injured patients more than 60% had a severe problem with oral intake, while only 16% displayed a mild or minimal dysfunction. |
|
Field and Weiss (1989) |
N=9 Retrospective review of patients with significant swallowing dysfunction selected from a total of 30 patients admitted to the Erie County Medical Center Head Injury Program. |
Most common problems were prolonged oral transit and delayed swallowing reflex. Each observed in 87.5% of the cases. 62.5% of the patients had pooling in the valleculae and in the pyriform sinuses. 50% had late triggering of the swallowing mechanism at the pyriform sinus. 37.5% had the bolus enter the hypopharynx prior to the swallow. Aspiration occurred in 37.5% of the cases and reduced pharyngeal peristalsis was observed in 25% of the cases. Two of the 8 patients required gastrostomy tube placement due to the severity of their swallowing problem. |
|
Winstein (1983) |
N=201 Retrospective review of consecutively admitted patients to a rehabilitation facility recovering from TBI. The method of swallowing assessment is not described. |
Swallowing difficulties were present in 55 (27%) patients on admission. 45 (82%) of these patients were not taking an oral diet. |
Conclusions
The incidence of dysphagia in patients entering rehabilitation post-ABI ranges from 25%-78%. This incidence has been shown to vary depending on the definition of dysphagia used and the acuity of the patient at admission. An incidence of 42%-65% in patients admitted to an ABI rehabilitation unit have been observed in more recent studies.
|
Dysphagia is common in patients admitted to ABI rehabilitation units.
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