What type of dysphagia is associated with laryngeal tuberculosis (TB) infection?

Type of Dysphagia in Laryngeal Tuberculosis Infection

Patients with laryngeal tuberculosis typically present with oropharyngeal dysphagia due to direct involvement of the pharyngolaryngeal structures, which may include pharyngolaryngeal paralysis in some cases.

Pathophysiological Mechanisms

Laryngeal tuberculosis can cause dysphagia through several mechanisms:

1. Direct tissue involvement:

   • Tuberculosis can cause focal, irregular thickening of the vocal cords and posterior laryngeal wall 1
   • Ulcerative lesions may develop in the laryngeal and pharyngeal mucosa

2. Neurological involvement:

   • Pharyngolaryngeal paralysis due to glossopharyngeal and vagus nerve impairment in the parapharyngeal space 2
   • This can lead to poor soft palate elevation, inadequate velopharyngeal closure, poor pharyngeal constrictor muscle contraction, and vocal cord immobility

3. Secondary complications:

   • Retropharyngeal abscess formation, which can cause mechanical obstruction 3
   • Lymphadenopathy affecting surrounding structures

Clinical Presentation

Patients with laryngeal tuberculosis typically present with:

• Dysphonia (hoarseness)
• Dysphagia (difficulty swallowing)
• Odynophagia (painful swallowing)
• Throat discomfort or sore throat
• Coughing or choking during swallowing (due to laryngeal penetration or aspiration) 4
• Food sticking sensation in the throat 4

Diagnostic Evaluation

The diagnosis of dysphagia in laryngeal tuberculosis requires:

1. Laryngoscopy: To visualize lesions of the vocal cords and ventricular strip 1

2. Imaging studies:

   • CT scan of the neck with IV contrast to assess laryngeal involvement 4
   • Videofluoroscopy to evaluate:
     • Bolus manipulation
     • Tongue motion
     • Hyoid and laryngeal elevation
     • Pharyngeal constrictor motion
     • Epiglottic tilt
     • Laryngeal penetration 4

3. Modified barium swallow: To assess oral and pharyngeal phases of swallowing 4

4. Biopsy: For histopathological confirmation of tuberculosis 1

Distinguishing Features

The dysphagia in laryngeal tuberculosis has several distinguishing features:

• It primarily affects the oropharyngeal phase of swallowing
• It may be associated with pharyngolaryngeal paralysis, which is rare in other forms of tuberculosis 2
• The dysphagia may be due to both mechanical obstruction and neurological impairment
• Unlike esophageal tuberculosis, which affects the esophageal phase of swallowing 5

Treatment and Prognosis

The good news is that pharyngolaryngeal paralysis and associated dysphagia in tuberculosis often resolve with appropriate anti-tuberculous treatment 2. The neuropathy typically recovers after treatment, making pharyngeal tuberculosis an important differential diagnosis to consider in cases of pharyngolaryngeal paralysis with dysphagia.

Important Clinical Caveat

Laryngeal tuberculosis can mimic laryngeal carcinoma on laryngoscopy and imaging 1, making histopathological confirmation essential for accurate diagnosis and appropriate treatment.