Background-Radiation alone or concurrent chemoradiation can result in severe swallowing disorders. This manuscript defines the swallowing disorders occurring at pretreatment and 3 and 12 months after completion of radiation or chemoradiation.

Objectives: To study whether 60-Hz stimulation, compared with routine 130 Hz, improves swallowing function and freezing of gait (FOG) in patients with Parkinson disease (PD) who undergo bilateral subthalamic nucleus (STN) deep brain stimulation (DBS). Methods:We studied 7 patients with PD who experienced FOG that persisted despite routine 130-Hz stimulation and dopaminergic medication. Each patient received 3 modified barium swallow (MBS) studies in a single day under 3 DBS conditions in the medication-on state: 130 Hz, 60 Hz, or DBS off, in a randomized double-blind manner. The laryngeal penetration and aspiration events were cautiously assessed, and a swallowing questionnaire was completed. The Unified Parkinson's Disease Rating Scale, Part III motor score, axial subscore, tremor subscore, and FOG by a questionnaire and stand-walk-sit test were also assessed. The best DBS condition (60 Hz here) producing the least FOG was maintained for 3 to 8 weeks, and patients were assessed again. Changes in measurements between the 60 Hz and 130 Hz were analyzed using paired t test, with swallowing function as primary and the remainder as secondary outcomes. Changes between other DBS conditions were further explored with Bonferroni correction.Results: Compared with the routine 130 Hz, 60-Hz stimulation significantly reduced aspiration frequency by 57% on MBS study and perceived swallowing difficulty by 80% on questionnaire. It also significantly reduced FOG, and axial and parkinsonian symptoms. The benefits at 60-Hz stimulation persisted over the average 6-week assessment. Conclusions:Compared with the routine 130 Hz, the 60-Hz stimulation significantly improved swallowing function, FOG, and axial and parkinsonian symptoms in patients with PD treated with bilateral STN-DBS, which persisted over the 6-week study period. 1-5 However, DBS is less effective at improving the axial symptoms of postural instability, gait disorders, and speech and swallowing dysfunction. STN-DBS might transiently improve the axial symptoms, but could make them worse over the course of 2 to 5 years. Classification of evidence:6-15 The DBS stimulation settings typically used in these studies were high frequency of 130 to 185 Hz.Recently, a stimulation frequency of 60 Hz has been found to improve the axial symptoms of freezing of gait (FOG) 16-19 and dysarthria 15,19 compared with the routinely used 130-Hz stimulation. However, whether or not the stimulation frequency could also affect another axial symptom, swallowing function, remains unknown. The answer to this question is critical, because dysphagia is frequently present in patients with mid-and late-stage PD 20,21 and is associated with

Patients were able to perceive decrements in their swallowing function as dysphagia and may have limited their oral intake in response to that perception. The ability to accurately perceive swallowing function may be useful for self-monitoring changes in dysphagia status during a course of swallow therapy.

Background-The relationship between type of chemoradiation treatment, site of disease, and swallowing function has not been sufficiently examined in patients with head and neck cancer treated primarily with chemoradiation.