## Overview Bilateral laryngeal paralysis is the uncommon loss of function of both arytenoid cartilages, so that neither can abduct (open) properly during inspiration. Unlike the far more common left-sided recurrent laryngeal neuropathy (“roaring”), bilateral disease produces severe airway obstruction that can be life-threatening at rest. Causes include lead toxicity, certain plant poisonings, trauma, post-anesthetic neuropathy, and occasional neurologic diseases. ## Causes Lead poisoning is a classic cause and should always be considered. Other toxins, bilateral recurrent laryngeal nerve trauma, post-anesthetic complications, and central or peripheral neuropathies (for example equine protozoal myeloencephalitis) can also produce bilateral paralysis. The evidence for exact frequency of each cause is limited. ## Diagnosis Endoscopy shows both arytenoids fixed in a paramedian or midline position with little or no movement. Horses present with severe inspiratory stridor and distress. Blood lead levels, neurologic examination, and additional imaging help identify the underlying cause. ## Treatment Emergency tracheostomy is often required to bypass the obstruction. Treatment of the primary disease (for example chelation for lead) is essential. Permanent tracheostomy or, in selected cases, arytenoidectomy may be needed for long-term management. Unilateral recovery sometimes occurs. ## Recovery and Prognosis Prognosis depends on the cause. Some toxic or post-anesthetic cases improve over weeks to months. Permanent bilateral paralysis usually requires lifelong airway management and limits athletic use. ## Prevention Avoidance of lead sources and careful anesthetic recovery reduce some risks. No specific prevention exists for idiopathic cases.
severe inspiratory noise; respiratory distress at rest; both arytenoids immobile on endoscopy; anxiety or collapse in advanced cases
## Overview Bilateral laryngeal paralysis is the uncommon loss of function of both arytenoid cartilages, so that neither can abduct (open) properly during inspiration. Unlike the far more common left-sided recurrent laryngeal neuropathy (“roaring”), bilateral disease produces severe airway obstruction that can be life-threatening at rest. Causes include lead toxicity, certain plant poisonings, trauma, post-anesthetic neuropathy, and occasional neurologic diseases. ## Causes Lead poisoning is a classic cause and should always be considered. Other toxins, bilateral recurrent laryngeal nerve trauma, post-anesthetic complications, and central or peripheral neuropathies (for example equine protozoal myeloencephalitis) can also produce bilateral paralysis. The evidence for exact frequency of each cause is limited. ## Diagnosis Endoscopy shows both arytenoids fixed in a paramedian or midline position with little or no movement. Horses present with severe inspiratory stridor and distress. Blood lead levels, neurologic examination, and additional imaging help identify the underlying cause. ## Treatment Emergency tracheostomy is often required to bypass the obstruction. Treatment of the primary disease (for example chelation for lead) is essential. Permanent tracheostomy or, in selected cases, arytenoidectomy may be needed for long-term management. Unilateral recovery sometimes occurs. ## Recovery and Prognosis Prognosis depends on the cause. Some toxic or post-anesthetic cases improve over weeks to months. Permanent bilateral paralysis usually requires lifelong airway management and limits athletic use. ## Prevention Avoidance of lead sources and careful anesthetic recovery reduce some risks. No specific prevention exists for idiopathic cases.
severe inspiratory noise; respiratory distress at rest; both arytenoids immobile on endoscopy; anxiety or collapse in advanced cases