Neurocardiogenic Syncope: Likelihood Ratios

Introduction:

Versus Ischemic Stroke. See also Subarachnoid Hemorrhage which shares some of the same findings (i.e. when intraparenchymal blood crosses into the subarachnoid space).

Great review of many findings (not all listed here): JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280

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Tags: Cardiac Problem Neurologic Tag this Diagnosis.

Differential Diagnoses include: Stroke, Syncope

Prevalence

Population / Calculator	Prevalence	Comments / Study / Link
Patients with syncope	33%	J Am Coll Cardiol 2001 Jun 1;37(7):1921-8. PMID 11401133
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The likelihood ratios of findings for Neurocardiogenic Syncope are listed below. See the left navigation bar to change the display.

Pre-Test Probability (Prevalence): %.	Post-Test Probability (Predictive Value): %.	Switch to display mode.
Note that calculating probabilities from more than one** finding is inherently inaccurate because findings are not independent. (For example, using two positive findings that share a common pathogenesis is likely to overestimate the true probability.)

Good Positive and Negative Likelihood Ratios
Finding	Result	+LR	-LR
[ + ] Xanthochromia	+ 0 -	14.2	0.3
(in CSF) Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Clinical diagnosis	+ 0 -	6.3	0.3
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280

Good Negative Likelihood Ratio
Finding	Result	+LR	-LR
[ + ] Tilt Table Test	+ 0 -	1.7	0.5
resulting in syncope after isoproterenol administration Differential Diagnosis: Syncope Study: Ann Intern Med 1992 Mar 1;116(5):358-63. PMID 1736767

Poorly Diagnostic Findings
Finding	Result	+LR	-LR
[ + ] Acute Onset	+ 0 -	0.6	1.8
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280

Good Positive Likelihood Ratio
Finding	Result	+LR	-LR
[ + ] Kernig or Brudzinski Sign	+ 0 -	7.5	0.9
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Neck Stiffness	+ 0 -	6.7	0.8
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Coma	+ 0 -	5.8	0.7
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Seizure	+ 0 -	4.5	0.9
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Hypertension	+ 0 -	4.4	0.6
diastolic > 110mmHg Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Headache	+ 0 -	2.6	0.7
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280

Negative Findings
Finding	Result	+LR	-LR
[ + ] Carotid Bruit	+ 0 -	0.1	1.1
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Atrial Fibrillation	+ 0 -	0.1	1.2
on EKG Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Alert	+ 0 -	0.3	2.5
i.e. as opposed to drowsy or comatose Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280
[ + ] Prior TIA	+ 0 -	0.3	1.2
Differential Diagnosis: Stroke Study: JAMA 2010;303(22):2280-2286 http://jama.ama-assn.org/cgi/content/short/303/22/2280