A feasibility pilot study of the effects of neurostimulation on dysphagia recovery in Parkinson’s Disease

Abstract

Introduction: Dysphagia often occurs during Parkinson’s disease (PD) and can have severe consequences. Recently, neuromodulatory techniques have been used to treat neurogenic dysphagia. Here we aimed to compare the neurophysiological and swallowing effects of three different types of neurostimulation, 5 Hertz (Hz) repetitive transcranial magnetic stimulation (rTMS), 1 Hz rTMS and pharyngeal electrical stimulation (PES). Method: 12 PD patients with dysphagia were randomised to receive either 5 Hz rTMS, 1 Hz rTMS, or PES. In a cross-over design, patients were assigned to one intervention and received both real and sham stimulation. Patients received a baseline videofluoroscopic (VFS) assessment of their swallowing, enabling penetration aspiration scores (PAs) to be calculated for: thin fluids, paste, solids and cup drinking. Swallowing timing measurements were also performed on thin fluid swallows only. They then had baseline recordings of motor evoked potentials (MEPs) from both pharyngeal and (as a control) abductor pollicis brevis (APB) cortical areas using single-pulse TMS. Subsequently, the intervention was administered and post interventional TMS recordings were taken at 0 and 30 minutes followed by a repeat VFS within 60 minutes of intervention. Results: All interventions were well tolerated. Due to lower than expected recruitment, statistical analysis of the data was not undertaken. However, with respect to PAs swallowing timings and MEP amplitudes, there was visual separation in a positive direction between active and sham groups for all interventions. Conclusion: PES, 5 Hz rTMS and 1 Hz rTMS are tolerable interventions in PD related dysphagia. Due to small patient numbers no definitive conclusions could be drawn from the data with respect to individual interventions improving swallowing function and comparative effectiveness between interventions. Larger future studies are needed to further explore the efficacy of these neuromodulatory treatments in Parkinson’s Disease associated dysphagia.

Dysphagia treatments in Parkinson's disease: A systematic review and meta‐analysis

“…Six included studies evaluated various forms of stimulation 34–39 . In general, these treatments can be classified into central and peripheral stimulation.…”

Evaluating the Therapeutic Application of Neuromodulation in the Human Swallowing System

“…More recently, a pilot study was published by Sasegbon et al, in 2021 in which PES was used to treat patients with Parkinson's associated dysphagia [121]. Although the technique was well tolerated in this patient group, low recruitment numbers resulted in a limited interpretation of the effects of PES in this population [121].…”

“…In this shamcontrolled study, PES resulted in significant improvements in electromyographic (EMG) recordings from external pharyngeal musculature and PAS scores at 2 weeks and 4 weeks post administration compared to sham [120]. More recently, a pilot study was published by Sasegbon et al, in 2021 in which PES was used to treat patients with Parkinson's associated dysphagia [121]. Although the technique was well tolerated in this patient group, low recruitment numbers resulted in a limited interpretation of the effects of PES in this population [121].…”

“…In patients with Parkinson's disease (PD), Khedr et al, found that 20 Hz rTMS applied over the hand motor cortex of both hemispheres for 10 days improved the timing of hyoid bone elevation and pharyngeal transit time for fluid swallowing [57]. Moreover, a recent pilot study compared the effects of different neuromodulation treatments for PD patients [58]. In this RCT study with cross-over design, twelve PD patients were randomized to receive either 1 Hz rTMS, 5 Hz rTMS or PES.…”

Advances in the Treatment of Dysphagia in Neurological Disorders: A Review of Current Evidence and Future Considerations

“…Apart from stroke patients, some studies have also suggested that NIBS may also be beneficial to patients with multiple sclerosis (MS) 95 and PD. 96 Moreover, application of NIBS in the cerebellum has received increasing attention in recent years. Some studies suggested that cerebellar rTMS may be beneficial for patients with post-stroke dysphagia.…”