This Article  • Extract  • PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citing articles on ISI (2)  • Contact me when this article is cited  Related Content  • Similar articles in JAMA  Topic Collections  • Neurology  • Alert me on articles by topic

To the Editor: Although syncope resulting from laughter has been described in a patient with extensive underlying arteriovascular disease,¹ we are unaware of any published reports of laugh syncope in an apparently healthy person.

Case Report
At 4 PM on a March day, a 32-year-old, previously healthy barber was standing and cutting a client’s hair. The client related a funny story, upon which the barber broke out into a very strong, sustained, loud, and unrestrained laughing fit during which, according to observers, he "blacked out" and fell to the floor. Although he sustained interscapular bruising and minor trauma to the right shoulder, he exhibited no seizure activity and no bladder or bowel incontinence. He regained consciousness within a few seconds, was completely oriented, had no apparent neurological deficit, and immediately resumed his work. He had been working on his feet throughout the day, but this was customary for him and he had never had a syncopal or near-syncopal episode before. The temperature at the time had been mild. The timing of his most recent meal was not recorded. The patient did not reveal the content of the story.

The patient had no personal or family history of diabetes, or of cardiac or neurological disease. He was taking no medications. He did not smoke, drink alcohol, or use recreational drugs.

Six hours later, when his back and shoulder became painful, he was brought to the emergency department. At that time, his systolic blood pressure was 110 mm Hg and his diastolic blood pressure was 70 mm Hg, supine, rhythm was sinus, and the heart rate was 74/min. His cardiac and neurological examination results were clinically normal. Blood chemistry tests, including glucose, were normal. His total creatine kinase level was elevated at 1225 U/L, but the troponin level was normal. Electrocardiogram, echocardiogram, chest radiograph, and head and chest computed axial tomographic scan were normal. Carotid scanning was not performed. There was no arrhythmia during 24 hours of cardiac monitoring. During 2 years of follow-up there were no further episodes of syncope or near syncope or any symptoms suggesting neurological or cardiac disease.

Comment
This episode most likely represents a Valsalva-type/vagally mediated syncopal attack caused by the sustained episode of laughing. Other causes of vagal syncope are not likely because of the presence of mild temperature and the lack of prior or subsequent episodes despite standing throughout the day. Immediate return to an asymptomatic state, with a normal blood glucose level in the emergency department, similarly makes hypoglycemia an unlikely explanation. Elevated creatine kinase level with normal troponin level is consistent with muscle contusion during the fall. Absence of other symptoms with the episode, combined with the negative diagnostic test results and lack of subsequent development of overt disease over 2 years, make an underlying cardiac or neurological condition unlikely.

The only previous report of laugh-induced syncope¹ occurred in a 62-year-old man who had 3 episodes of syncope while laughing during watching "Seinfeld" on television. That patient also smoked, had hypertension and hypercholesterolemia, and had a history of coronary artery bypass graft surgery. He had widespread coronary and peripheral arterial narrowing (including carotid occlusion), with 90% occlusion in the brachiocephalic trunk. This lesion was believed to be the principal cause of the syncope because there was no recurrence after it was opened by angioplasty.

In contrast, our patient appears to represent the first reported case in an otherwise normal, healthy person. Laughing predisposes the patient to increased intrathoracic venous pressure, which is considered the underlying mechanism for syncope from such well-recognized causes as coughing, sneezing, the Valsalva maneuver, and weight lifting. These events are usually associated with acute vasodilatation of the vascular bed, reduced cardiac output, and relative bradycardia,^2-3 producing transient reduction of cerebral circulation.

The physiological as well as the acoustic similarities between coughing and laughing episodes are great. Both share a sustained state of repetitive bursts of progressive, forced expiration. They constitute a staccato pattern rather than the continuous Valsalva-like state produced by forced voiding, defecating, sneezing, swallowing, and blowing against obstruction. An extensive review of syncope⁴ describes 15 variations of vasovagal syncope concluding with weight lifting and trumpet playing, but not including laughing.

Laughter has frequently been proposed to be the best medicine. However, as with any intervention, an excessive dose may result in adverse events.

Financial Disclosures: None reported.

Dennis Bloomfield, MD
DbloomfieldMD{at}aol.com

Saad Jazrawi, MD
St Vincent Catholic Medical Centers
Staten Island, NY

1. Cox SV, Eisenhauer AC, Hreib K. Seinfeld syncope. Cathet Cardiovasc Diagn. 1997;42:242. FULL TEXT | ISI | PUBMED 2. Alboni P, Brignole M, Menozzi C, et al. Diagnostic value of history in patients with syncope with or without heart disease. J Am Coll Cardiol. 2001;37:1921. FREE FULL TEXT 3. Arthur W, Kaye GC. The pathophysiology of common causes of syncope. Postgrad Med J. 2000;76:750-753. FREE FULL TEXT 4. Manolis AS, Linzer M, Saleem D, Estes NH. Syncope. Ann Intern Med. 1990;112:850-863. ISI | PUBMED

Letters Section Editor: Robert M. Golub, MD, Senior Editor.

JAMA. 2005;293:2863-2864.