Impact of acuinjection at ST36 on leg movements, their associated respiratory events, and electroencephalographic arousals in patients with obstructive sleep apnea: A case series.

RATIONALE

Leg movements (LMs) frequently co-occur with obstructive sleep apnea (OSA), and respiratory-related LMs can trigger arrhythmias and cause diagnostic challenges during polysomnography (PSG). While the cardiovascular burden of periodic limb movements in sleep is recognized, little is known about the role of LM suppression during PSG in improving diagnostic accuracy. This case series examines the impact of acuinjection at ST36 on LM suppression during PSG in patients with OSA.

PATIENT CONCERNS

All 3 patients underwent diagnostic PSG due to suspected OSA. PSG was temporarily paused during acuinjection, and the PSG period was divided as follows: Pre-a (before acuinjection), Post-a (from PSG resumption to LM recurrence, defined as multiple LMs within a 5-minute period), and restarted PSG (the remaining PSG time after resumption, excluding any positive airway pressure titration if applicable). In each case, frequent LMs associated with arousals were observed during Pre-a, interfering with sleep quality and complicating the interpretation of respiratory events.

DIAGNOSES

Initial PSG findings were suggestive of moderate to severe OSA with frequent LMs and associated arousals. Respiratory events were often temporally linked to LMs, resulting in substantial sleep fragmentation and diagnostic uncertainty.

INTERVENTIONS

Acuinjection was performed bilaterally at ST36 using pentazocine (3.75 mg in 0.5 mL normal saline in 1 case, and 7.5 mg in 1.0 mL in 2 cases). PSG was resumed immediately afterward.

OUTCOMES

Outcomes were assessed using the apnea-hypopnea index (AHI), hypopnea index (HI), leg movement index (LMI), respiratory-related leg movement index (rLMI), and arousal index (ArI). In the Pre-a period (mean: 76.7 minutes), severe OSA with high LMI and ArI was observed: AHI 72.6, HI 72.3 (obstructive HI: 39.1, central HI: 33.2), LMI 141.6, rLMI 68.4, and ArI 100.0. In the Post-a period (184.8 minutes), these indices markedly improved: AHI 19.9, HI 18.9, LMI 5.9, rLMI 0.7, and ArI 36.7. During the restarted PSG (357.6 minutes), AHI, LMI, and ArI remained low at 23.4, 13.4, and 36.9, respectively. No adverse effects were observed.

LESSONS

This case series suggests that acuinjection at ST36 may effectively suppress LMs and associated arousals during PSG in OSA patients, thereby facilitating more accurate diagnosis and characterization of respiratory events.