The diagnostic value of urinary incontinence in the differential diagnosis of seizures

Purpose Urinary incontinence may occur both in epileptic seizures (ES) and in non-epileptic events (NEE) such as psychogenic nonepileptic events (PNEEs) and syncope. A comprehensive search of the literature to determine the accuracy of this physical finding and its prevalence in epileptic seizures and syncope is still lacking. To undertake a systematic review to determine sensitivity, specificity and likelihood ratios (LR) of urinary incontinence in the differential diagnosis between ES and NEEs (including syncope and PNEEs). Methods Studies evaluating the presence of urinary incontinence in ES and NEEs were systematically searched. Sensitivity, specificity, positive and negative likelihood ratio (pLR, nLR) of incontinence were determined for each study and for the pooled results. Results Five studies (221 epilepsy patients and 252 subjects with NEEs) were included. Pooled accuracy measures of urinary incontinence (ES versus NEEs) were: sensitivity 38%, specificity 57%, pLR 0.879 (95% CI 0.705–1.095) and nLR 1.092 (95% CI 0.941–1.268). For each comparison (epileptic seizures versus NEEs; ES versus syncope; ES versus PNEEs), pooled accuracy measures for urinary incontinence showed a statistically not significant pLR (the 95% CI of the pooled value included 1, and the LR value of 1 has no discriminatory value). Conclusions A pooled analysis of data from the literature shows that urinary incontinence has no value either in the differential diagnostic between ES and syncope/PNEEs. Systematic reviews with pooled analyses of data from the literature allow an increase in statistical power and an improvement in precision, representing a useful tool to determine the accuracy of a certain physical finding in the differential diagnosis between ES and other paroxysmal events.