Botulinum Toxin in the Palatopharyngeal Muscle for the Treatment of Obstructive Sleep Apnea

EVALUATION OF BOTULINUM TOXIN IN THE PALATOPHARYNGEAL MUSCLE FOR THE TREATMENT OF OBSTRUCTIVE SLEEP APNEA

Obstructive Sleep Apnea (OSA) is a sleep-related breathing disorder characterized by recurrent collapse of the upper airway during sleep, in which the palatopharyngeal muscle plays a key role in pathophysiology. Although continuous positive airway pressure (CPAP) remains the standard treatment, adherence is often suboptimal. Botulinum toxin type A (BoNT-A), a peripheral neuromodulator, has been proposed as a potential therapeutic alternative by inducing chemodenervation and muscle volume reduction, thereby potentially increasing upper airway patency. This study aims to evaluate the efficacy and safety of BoNT-A injection into the palatopharyngeal muscle in patients with moderate to severe OSA. This is a prospective, single-arm, interventional clinical trial with pre- and post-intervention assessment. We hypothesize that the intervention will result in a significant reduction in the Apnea-Hypopnea Index (AHI), along with improvements in secondary outcomes such as excessive daytime sleepiness and oxygenation parameters.

Inclusion Criteria:

• Diagnosis of moderate to severe OSA, confirmed by home or laboratory polysomnography.
• Age between 18 and 50 years.
• BMI in the range of 18.5-30.
• Neck circumference ≤ 44 cm (men) and ≤ 42 cm (women).
• Absence of signs of upper obstruction

Exclusion Criteria:

• Skeletal or craniofacial disorders:
• Tonsillar hypertrophy 3-4
• Obesity (BMI > 30 kg/m²)
• Elderly (age > 50 years)
• Neuromuscular diseases (e.g., dystrophies, myasthenia gravis)
• Chronic use of medications that alter muscle tone.
• Excessive alcohol consumption (> 14 drinks/week)
• Chronic obstructive pulmonary disease (COPD)
• Congestive heart failure (NYHA III-IV) or decompensated heart disease.
• Concomitant sleep disorders: narcolepsy, restless legs syndrome, sleep behavior disorder (REM).
• Predominant central or mixed sleep apnea on polysomnography (≥ 50% central events).
• Previous airway surgery (uvulopalatopharyngoplasty, recent tonsillectomy).
• Pregnancy or postpartum (< 6 months).
• Neurological conditions: Previous stroke, Parkinson's disease, dementia.