Pharyngeal Electrical Stimulation (PES) for Neurogenic Dysphagia: An Overview

Posted by Michael A. S. Guth on December 20th, 2025

Pharyngeal Electrical Stimulation (PES) for Neurogenic Dysphagia: An Overview

Introduction to Neurogenic Dysphagia and the Need for Restorative Therapy

Neurogenic dysphagia (ND) is a swallowing impairment resulting from neurological damage, most commonly caused by stroke, multiple sclerosis (MS), traumatic brain injury, or neurodegenerative diseases.1 ND is associated with severe complications, including malnutrition, dehydration, and aspiration pneumonia, which significantly increases morbidity and mortality.2

Traditionally, dysphagia management has relied heavily on compensatory strategies (e.g., thickened liquids, postural changes) or enteral feeding (feeding tubes).3 While necessary for immediate safety, these approaches do not treat the underlying neurological deficit. Consequently, there has been a growing demand for restorative therapies that target neuroplasticity to recover swallowing function. Pharyngeal Electrical Stimulation (PES) has emerged as a leading technique in this restorative domain.

The PES Procedure

As described in the initial text, PES is carried out via location-specific intraluminal catheters. These catheters are designed with integrated ring electrodes at the distal tip.

  • Placement: The catheter is introduced transnasally by a clinician until the electrodes are positioned directly within the pharynx. Accurate positioning is crucial to ensure stimulation targets the appropriate sensory receptors in the pharyngeal mucosa.

  • Stimulation Parameters: Once positioned, the catheter delivers defined electrical pulses. The intensity is usually titrated to the patient’s individual sensory threshold (the point at which they first feel a tingling sensation) and then set at an optimal therapeutic level, which is typically strong but not painful.4
  • Treatment Regimen: A common protocol involves daily sessions lasting approximately 10 minutes for a period of 3 to 5 consecutive days, often performed at the bedside in acute or rehabilitation settings.

Mechanism of Action: Driving Neuroplasticity

The core premise of PES is that augmenting sensory input from the periphery can drive central nervous system reorganization.5 Your text correctly identifies that PES likely works by “increasing corticobulbar excitability and inducing cortical reorganization of swallowing motor cortex.”

To elaborate on this physiological process:

  1. Sensory Bombardment: The pharynx is richly innervated with sensory receptors crucial for triggering the swallow reflex.6 PES provides intense, controlled afferent (sensory) stimulation to these nerves (primarily the glossopharyngeal and vagus nerves).7
  2. Corticobulbar Pathway Activation: These sensory signals travel up to the brainstem swallowing centers and further to the sensorimotor cortex. In patients with neurological damage, the cortical representation of swallowing is often suppressed or damaged.8
  3. Cortical Reorganization (Neuroplasticity): The repetitive sensory input from PES acts to increase the excitability of the corresponding motor cortex areas.9 Over time, this can “reawaken” dormant neural pathways or recruit adjacent, undamaged cortical areas to take over the swallowing function—a process known as adaptive cortical reorganization.

Clinical Evidence and Target Populations

PES is transitioning from an experimental therapy to clinical practice due to an increasingly promising evidence base.10

  • Stroke: The strongest evidence for PES lies in post-stroke dysphagia. Several randomized controlled trials have demonstrated that PES can accelerate swallowing recovery, reduce the severity of aspiration, and lead to earlier decannulation (removal) of tracheostomy tubes and weaning from feeding tubes compared to standard care.11
  • Multiple Sclerosis (MS): As noted, PES shows promise in MS patients. Dysphagia in MS is often related to brainstem lesions.12 PES appears effective in enhancing residual sensory pathways in these patients, improving swallow coordination and safety.13

  • Other Applications: Research is ongoing into the use of PES for dysphagia related to Parkinson’s disease and critical illness polyneuropathy following prolonged ICU stays.14

Summary

Pharyngeal Electrical Stimulation represents a significant shift in dysphagia management, moving from purely compensatory measures to active neurological rehabilitation. By directly stimulating the pharynx to harness the brain’s innate ability to reorganize, PES offers a restorative therapeutic option for improving swallowing performance in complex neurogenic conditions like stroke and multiple sclerosis.15 

What the Meta-Analysis Shows (The Positive Findings):

  1. Statistically Significant Improvement in Swallowing Function: The overall analysis found that the PES group had better swallowing function scores than the control group (SMD = -0.20, P=0.02). The specific Dysphagia Severity Rating Scale (DSRS) also showed a significant difference (P=0.05). This means PES has a measurable, positive effect on improving the severity of dysphagia.

  2. Clinically Meaningful Outcome: Nasogastric Tube Withdrawal: This is the strongest piece of evidence for a tangible, life-changing benefit. The PES group had a nearly 3 times higher rate of having their feeding tubes removed (RR = 2.88, P=0.02). For a patient, this means transitioning from tube feeding back to oral intake—a massive improvement in quality of life, autonomy, and a reduced risk of tube-related complications.

The Limitations and “Lacking Evidence” (The Reality Check):

  1. The Effect Size is Modest: The Standardized Mean Difference (SMD) of -0.20 for overall swallowing function is considered a small effect size. This suggests that while there is a real benefit, the average improvement across all patients is not dramatic. It indicates PES is an effective adjuvant therapy, not a standalone cure.

  2. What It Did Not Clearly Prove (Based on This Review):

    • Reduction in Aspiration: The review states evidence for reducing aspiration is lacking. The Penetration-Aspiration Scale (PAS) is mentioned as an outcome in some studies, but no pooled significant result is reported. This is critical because preventing pneumonia is a primary goal of dysphagia therapy.

    • Shorter Hospital Stays (LOS): No significant difference was found in length of stay. This suggests that while PES improves function, it may not accelerate the overall complex discharge process for stroke patients.

    • Generalizability to All Patients: The included studies (2010-2018) likely had specific inclusion/exclusion criteria. PES may work best for patients with a certain type or severity of dysphagia (e.g., pharyngeal phase impairment) and not for those with very severe or complete loss of swallow function.

Conclusion: Making Swallowing Possible vs. Meaningfully Helping

  • For some patients, PES may indeed “make swallowing possible.” The high rate of nasogastric tube withdrawal strongly implies that a number of patients regained functional, safe enough oral intake to eliminate the need for tube feeding. This is a transformative outcome.

  • For the broader population, PES is a valuable tool that “meaningfully helps.” It provides a statistically significant boost to swallowing rehabilitation, contributing to measurable functional gains. It is not a passive “fix”; it is an assistive technology that enhances neuroplasticity and should be integrated into a comprehensive dysphagia therapy program (including compensatory strategies, strengthening exercises, etc.).

In summary, your meta-analysis supports that PES is an evidence-based, effective intervention for post-stroke dysphagia with a particularly strong impact on achieving oral feeding independence (tube withdrawal). Its effect is real and clinically important, but its role is that of a potent facilitator within a broader rehabilitation context, rather than a universal “on-switch” for swallowing. The call for further studies on aspiration and functional oral intake is warranted to better define its optimal use and patient selection.

Posted in Neuroplasticity, Pharma and Medical Device
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