Dysphagia in Parkinson's disease patients prior to deep brain stimulation: Is screening accurate?

Background: Swallowing problems are common in Parkinson's Disease (PD) and aspiration pneumonia is the leading cause of death. Deep brain stimulation (DBS) surgery can successfully manage the motor symptoms of PD when pharmacological management begins to fail. Before DBS it is important to identify baseline dysfunction, but no consensus regarding swallowing screening exists. Objectives: This study was undertaken to: 1) identify the prevalence of dysphagia prior to DBS; and 2) determine if screening measures or other characteristics were predictive for reduced airway protection. Methods: A standardized protocol was performed for 137 consecutive patients with idiopathic PD and no confounding medical conditions, including those referred for work-up of dysphagia (n = 57) and those prior to DBS (n = 80). Three validated screening measures were completed before videofluoroscopic evaluation. Results: On videofluoroscopy, there were significant differences in reduced airway protection by group (dysphagia group: 44 %; pre-DBS group: 21 %). Aspiration also differed by group (dysphagia group: 18 %; pre-DBS group: 8 %) although not significantly. Although there were significant between-group differences, none of the screening measures was predictive of reduced airway protection or aspiration in the sample overall. Male gender, previous videofluoroscopic evaluation, history of pneumonia, and previous DBS surgery were associated with increased aspiration-risk. Age also showed a modest correlation. Conclusions: Dysphagia is not uncommon prior to DBS. No screening measure accurately predicted reduced airway protection on videofluoroscopy. Abnormal findings on clinical assessment prior to DBS, particularly in patients that are older, male, or have a history of pneumonia, may identify individuals requiring an objective dysphagia evaluation.