What is the therapy that involves applying electrical frequencies or vibrations to the vocal cord from the neck for vocal cord paresis?

Laryngeal Electromyography (LEMG) and Electrical Stimulation Therapy for Vocal Cord Paresis

The therapy that involves applying electrical frequencies or vibrations to the vocal cord from the neck for vocal cord paresis is called Electrical Stimulation Therapy (EST) or Neuromuscular Electrical Stimulation (NMES). This approach is used as an adjunctive treatment to traditional voice therapy exercises in patients with vocal fold paresis 1, 2.

How Electrical Stimulation Therapy Works

Electrical stimulation therapy for vocal cord paresis involves:

• Applying electrical currents through electrodes placed on the neck over the laryngeal region
• Stimulating the affected laryngeal muscles to improve their function
• Synchronizing electrical stimuli with vocal fold vibration in some advanced approaches 3
• Supporting traditional voice exercises to enhance treatment outcomes

Evidence for Effectiveness

Research indicates that electrical stimulation therapy can be beneficial:

• A prospective, randomized trial of 90 patients with unilateral recurrent laryngeal nerve paresis found that electrical stimulation-supported voice exercises produced significantly greater improvement in vocal fold vibration regularity compared to voice exercises alone 2
• Another study with 90 patients demonstrated that electrical stimulation therapy was more effective at increasing vibration stability than traditional voice therapy 1
• Synchronous electrical stimulation (timed with vocal fold vibration) has shown promise for improving voice quality parameters in patients with unilateral recurrent laryngeal nerve paralysis 3

Clinical Application

When considering electrical stimulation therapy:

• It is most appropriate for patients with confirmed neurogenic vocal fold paresis/paralysis
• Laryngeal Electromyography (LEMG) should first be performed to differentiate between neurogenic and mechanical causes of vocal fold immobility 4
• LEMG is most valuable when performed between 21 days and 6 months after symptom onset 4
• Treatment is typically administered in conjunction with traditional voice therapy exercises

Important Considerations

Several factors should be considered when evaluating this treatment option:

• The Neurolaryngology Study Group does not recommend Electromagnetic Stimulation (EMS) as a standard treatment due to lack of long-term follow-up and limited clinical trials 4
• Different stimulation protocols and electrode positioning have been used across studies, making standardization difficult 5
• Early intervention is critical for optimal outcomes in vocal fold paralysis 4
• LEMG is useful not only for diagnosis but also for providing prognostic information about potential recovery 4

Pitfalls to Avoid

When considering electrical stimulation therapy:

• Don't use this therapy without first confirming the diagnosis with laryngoscopy and appropriate imaging
• Don't confuse arytenoid dislocation/fixation with true neurogenic paralysis (LEMG can help differentiate)
• Don't make permanent surgical decisions before determining if spontaneous recovery will occur
• Don't use electrical stimulation as the sole treatment; it should complement voice therapy exercises

While electrical stimulation therapy shows promise for treating vocal fold paresis, more standardized research is needed to fully establish its long-term benefits and optimal protocols.