PT  - JOURNAL ARTICLE
AU  - Chen, Min
AU  - Jamnadas-Khoda, Jenny
AU  - Broadhurst, Mark
AU  - Wall, Melanie
AU  - Grünewald, Richard
AU  - Howell, Stephen J.L.
AU  - Koepp, Matthias
AU  - Parry, Steve W.
AU  - Sisodiya, Sanjay M.
AU  - Walker, Matthew
AU  - Hesdorffer, Dale
AU  - Reuber, Markus
TI  - Value of witness observations in the differential diagnosis of transient loss of consciousness
AID  - 10.1212/WNL.0000000000007017
DP  - 2019 Feb 26
TA  - Neurology
PG  - e895--e904
VI  - 92
IP  - 9
4099  - http://n.neurology.org/content/92/9/e895.short
4100  - http://n.neurology.org/content/92/9/e895.full
SO  - Neurology2019 Feb 26; 92
AB  - Objective This retrospective study explores to what extent additional information from event witnesses provided using the novel 31-item Paroxysmal Event Observer (PEO) Questionnaire improves the differentiation among epilepsy, syncope, and psychogenic nonepileptic seizures (PNES) achievable with information provided by patients alone.Methods Patients with transient loss of consciousness caused by proven epilepsy (n = 86), syncope (n = 79), or PNES (n = 84) attending specialist neurology/syncope services in the United Kingdom and event observers provided Paroxysmal Event Profile (PEP), PEO, and personal information (PI) (e.g., sex, age, medical history) data. PEO data were subjected to exploratory factor analysis (EFA) followed by confirmatory factor analysis (CFA). PEO, PEP, and PI data were used separately and in combination to differentiate diagnoses by pairwise and multinomial logistic regressions. Predicted diagnoses were compared with gold standard medical diagnoses.Results EFA/CFA identified a 4-factor structure of the PEO based on 26/31 questionnaire items with loadings ≥0.4. Observer-reported factors alone differentiated better between syncope and epilepsy than patient-reported factors (accuracy: 96% vs 85%, p = 0.0004). Observer-reported data improved accuracy over differentiation based on patient-reported data alone from 90% to 100% between syncope and epilepsy (p = 0.005), 76% to 83% between epilepsy and PNES (p = 0.006), and 93% to 95% between syncope and PNES (p = 0.098).Conclusions Information from observers can make an important contribution to the differentiation of epilepsy from syncope or PNES but adds less to that of syncope from PNES.ANOVA=analysis of variance; CFI=comparative fit index; EFA=exploratory factor analysis; PEO=Paroxysmal Event Observer; PEP=Paroxysmal Event Profile; PI=patient information; PNES=psychogenic nonepileptic seizures; RMSEA=root mean square error approximation; TLI=Tucker Lewis index; TLOC=transient loss of consciousness