Related Experiment Video
Updated: Jun 30, 2026

Single-stage Dynamic Reanimation of the Smile in Irreversible Facial Paralysis by Free Functional Muscle Transfer
Published on: March 1, 2015
[Spasmodic laughter syncope. An unusual complication of pseudobulbar palsy]
1Service de neurologie, Hôtel-Dieu de France, Achrafieh, Beyrouth, Liban. awadaadnan@yahoo.com
Introduction:
Spasmodic laughter is a classical sign of pseudobulbar palsy, but it has never been reported, to our knowledge, to provoke syncope.
Case Report:
A 63-year-old hypertensive and diabetic man with peripheral neuropathy and lacunar pseudobulbar palsy presented with three episodes of spasmodic laughter which had induced syncope. No new episode was observed after the beginning of low dose bisoprolol.
Discussion:
Sustained or spasmodic laughter is accompanied by repetitive bursts of forced expiration, corresponding to short repetitive Valsalva maneuvers. Laughter-induced syncope is considered as one of the many Valsalva-type/vagally mediated syncopal attacks leading to rapid fall in blood pressure without compensatory tachycardia. The presence of autonomic diabetic neuropathy may also contribute to these attacks.
Related Concept Videos
Alterations in Muscle Tone ll
Botulism
Tetanus
Alterations in Muscle Tone lll
Somatic Spinal Reflexes
One of the most well-known somatic spinal reflexes is the stretch reflex, which is activated by the sudden stretching of a muscle. This reflex involves the activation of specialized sensory receptors called muscle spindles, which are located in the muscle tissue and detect changes in the length and speed of muscle contractions. When a muscle is suddenly...
Poliomyelitis

