Laryngeal electromyography in amyotrophic lateral sclerosis

Area of Science:

• Neurology
• Clinical Electrophysiology

Background:

• Bulbar involvement is characteristic of amyotrophic lateral sclerosis (ALS).
• Laryngeal involvement in ALS remains understudied regarding its frequency, pattern, and clinical significance.

Purpose of the Study:

• To investigate the frequency, pattern, and clinical relevance of laryngeal muscle involvement in ALS.
• To evaluate laryngeal electromyography (LEMG) as a diagnostic tool for ALS.

Main Methods:

• Twenty-six patients with spinal-onset ALS underwent nasofibroscopy (NF) and laryngeal electromyography (LEMG).
• Resting activity and motor unit potentials of genioglossus and masseter muscles were also assessed.

Main Results:

• Neurogenic changes were found in at least one laryngeal muscle in 24 patients.
• LEMG identified laryngeal denervation in 11 of 12 patients with normal NF, and 16 patients showed specific neurogenic changes.
• No patient had tongue neurogenic changes with normal LEMG, and 14 patients had abnormal NF findings.

Conclusions:

• Laryngeal electromyography (LEMG) effectively identifies laryngeal denervation in ALS patients.
• LEMG can detect laryngeal changes prior to noticeable clinical symptoms.
• LEMG serves as a valuable diagnostic aid for suspected ALS cases.