Suprahyoid Muscle Activity in Patients with Chagasic Megaesophagus

Area of Science:

• Gastroenterology
• Neurology
• Physiology

Background:

• Achalasia is a primary esophageal motility disorder.
• Chagas' disease, caused by Trypanosoma cruzi, can lead to megaesophagus, a form of achalasia.
• Swallowing function is complex and involves coordinated muscle activity.

Purpose of the Study:

• To evaluate suprahyoid muscle activity during swallowing in patients with Chagas' disease-induced megaesophagus.
• To correlate this activity with the severity of megaesophagus and videofluoroscopic findings.
• To investigate the relationship between muscle activity and esophageal manometry results.

Main Methods:

• Surface electromyography of suprahyoid muscles during swallowing.
• Videofluoroscopy to assess oral and pharyngeal swallowing phases.
• Comparison between 29 Chagas' disease patients and 29 controls.
• Statistical analysis including Canonical Correlation, MANOVA, Spearman, and Logistic Regression tests.

Main Results:

• Chagas' disease patients showed significantly lower suprahyoid muscle electromyographic activity compared to controls.
• A positive correlation was observed between maximum voluntary isometric contraction and pharyngeal transit time for both liquid and paste consistencies.
• No association was found between suprahyoid muscle activity and esophageal manometry findings.

Conclusions:

• Individuals with chagasic megaesophagus demonstrate reduced suprahyoid muscle activation during swallowing.
• Increased pharyngeal transit time in these patients suggests compensatory suprahyoid muscle recruitment.
• These findings highlight altered swallowing biomechanics in Chagas' disease-related megaesophagus.