Karen L. Wallace

Bio: Karen L. Wallace is an academic researcher from University of New South Wales. The author has contributed to research in topics: Dysphagia & Swallowing. The author has an hindex of 11, co-authored 12 publications receiving 930 citations. Previous affiliations of Karen L. Wallace include St George's Hospital.

Influence of aging on oral-pharyngeal bolus transit and clearance during swallowing: scintigraphic study.

Abstract: The aim of the study was to determine the influence of normal aging on regional transit and the efficiency of bolus clearance during the oral and pharyngeal phases of swallowing. We compared scintigraphically derived oral-pharyngeal transit times and isotope clearance during swallowing in 21 healthy aged volunteers (mean age 68 +/- 8 yr) and 9 young controls (mean age 28 +/- 7.5 yr). Subjects swallowed 5- and 10-ml water boluses mixed with 30 MBq 99mtechnetium tin colloid. Oral and pharyngeal transit times, pharyngeal clearance time, and postswallow residual counts in each region were derived from time-activity curves. Pharyngeal residual counts were significantly greater in the aged than in controls (P = 0.0008), but age did not influence oral residual. Aging significantly prolonged oral transit time (P = 0.02), pharyngeal transit time (P = 0.0004), and pharyngeal clearance time (P = 0.0001). We conclude that normal impairs the efficiency of pharyngeal clearance during swallowing, prolongs scintigraphic measures of oral-pharyngeal transit, and increases the exposure time of the glottis to the swallowed bolus.

Predictors of Outcome following Cricopharyngeal Disruption for Pharyngeal Dysphagia

Abstract: The indications for, and predictors of outcome following cricopharyngeal disruption in pharyngeal dysphagia are not clearly defined. Our purpose was to examine the symptomatic response to cricopharyngeal disruption, by either myotomy or dilatation, in patients with oral-pharyngeal dysphagia and to determine pretreatment manometric or radiographic predictors of outcome. Using simultaneous pharyngeal videoradiography and manometry, we studied 20 patients with pharyngeal dysphagia prior to cricopharyngeal diltation (n = 11) or myotomy (n = 8), and 23 healthy controls. We measured peak pharyngeal pressure, hypopharyngeal intrabolus pressure, upper esophageal sphincter diameter, and coordination. Response rate to sphincter disruption was 65%. The extent of sphincter opening was significantly reduced in patients compared with controls (p= 0.004), but impaired sphincter opening was not a predictor of outcome. Increased hypopharyngeal intrabolus pressures (>19 mmHg for 10 ml bolus; >31 mmHg for 20 ml bolus) was a significant predictor of outcome (p= 0.01). Neither peak pharyngeal pressure nor incoordination were predictors of outcome. In pharyngeal dysphagia, hypopharyngeal intrabolus pressure, and not peak pharyngeal pressure, is a predictor of response to cricopharyngeal disruption. The relationship between intrabolus pressure and impaired sphincter opening is an indirect measure of sphincter compliance which helps predict therapeutic response.

Validity and reliability of the Eating Assessment Tool (EAT-10).

Abstract: Objectives:The Eating Assessment Tool is a self-administered, symptom-specific outcome instrument for dysphagia. The purpose of this study was to assess the validity and reliability of the 10-item ...

Modern diagnosis of GERD: the Lyon Consensus

Abstract: Clinical history, questionnaire data and response to antisecretory therapy are insufficient to make a conclusive diagnosis of GERD in isolation, but are of value in determining need for further investigation. Conclusive evidence for reflux on oesophageal testing include advanced grade erosive oesophagitis (LA grades C and D), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal oesophageal acid exposure time (AET) >6% on ambulatory pH or pH-impedance monitoring. A normal endoscopy does not exclude GERD, but provides supportive evidence refuting GERD in conjunction with distal AET

Gastrointestinal dysfunction in Parkinson's disease.

Abstract: There is growing recognition that gastrointestinal dysfunction is common in Parkinson's disease (PD). Virtually all parts of the gastrointestinal tract can be affected, in some cases early in the disease course. Weight loss is common but poorly understood in people with PD. Dysphagia can result from dysfunction at the mouth, pharynx, and oesophagus and may predispose individuals to aspiration (accidental inhalation of food or liquid). Gastroparesis can produce various symptoms in patients with PD and may cause erratic absorption of drugs given to treat the disorder. Bowel dysfunction can consist of both slowed colonic transit with consequent reduced bowel-movement frequency, and difficulty with the act of defecation itself with excessive straining and incomplete emptying. Recognition of these gastrointestinal complications can lead to earlier and potentially more effective therapeutic intervention.

Gastrointestinal dysfunction in Parkinson's disease.

Abstract: Gastrointestinal dysfunction is a frequent and occasionally dominating symptom of Parkinson's disease (PD). Features of gastrointestinal dysfunction include disordered control of saliva, dysphagia, gastroparesis, constipation in the sense of decreased bowel movement frequency, and defecatory dysfunction necessitating increased straining and resulting in incomplete evacuation. Excess saliva accumulates in the mouth because of decreased swallowing frequency. Dysphagia develops in approximately 50% of patients and may be a reflection of both central nervous system and enteric nervous system derangement. Gastroparesis may produce a variety of symptoms, including nausea, and also may be responsible for some of the motor fluctuations seen with levodopa therapy. Bowel dysfunction in PD may be the result of both delayed colon transit and impaired anorectal muscle coordination.