Clinical utility of ictal eyes closure in the differential diagnosis between epileptic seizures and psychogenic events

SummaryThe presence of ictal eye closure (IEC) has been considered to represent an additional clinical sign supporting the diagnosis of psychogenic non-epileptic events (PNEEs).We undertook a systematic review to evaluate sensitivity, specificity and likelihood ratios (LR) of IEC in the differential diagnosis between PNEEs and epileptic seizures. Six studies (total of 1496 events; 1021 epileptic seizures and 475 PNEEs) were included.Pooled accuracy measures of IEC for the diagnosis of PNEE were: sensitivity 58% (0.579) (95% CI 0.534–0.623), specificity 80% (0.895) (95% 0.875–0.9131)%, pLR 5.524 (95% CI 4.546–6.714) and nLR 0.47 (95% CI 0.422–0.524).However, a sensitivity analysis including only the studies performing an IEC assessment blinded to the diagnoses yielded results indicative of a rather low diagnostic value of IEC (pLR 3.056) compared with the analysis including unblinded studies (pLR 12.754).Further studies evaluating the occurrence of IEC through direct observation by means of video-EEG recording and blind to both EEG tracings and patient diagnosis are therefore required to definitely estimate the diagnostic utility of this sign in the differential diagnosis between epileptic seizures and PNEEs.

Graphical abstractThe presence of ictal eye closure (IEC) has been considered to represent an additional clinical sign supporting the diagnosis of psychogenic non-epileptic events (PNEEs). The probability of PNEE is estimated by means of a nomogram describing how pre-test probability relates to post-test probability given the pLR for IEC. When in doubt between the diagnosis of seizure and that of PNEE, for instance with a pre-test probability of PNEE of 50%, the presence of IEC increases the chance that the patient had a PNEE (continuous line) (pLR = 5.524). A pooled analysis of data from the literature shows that IEC is a physical sign with high specificity and high pLR for PNEEs. A careful history of seizure semiology in an outpatient setting might help to discern between seizures and PNEE, although a video-recording of the paroxysmal event still represents the reference standard to properly differentiate between the two conditions.Figure optionsDownload full-size imageDownload high-quality image (55 K)Download as PowerPoint slide