Wegraking: epileptische aanval of syncope? Een prospectief onderzoek

To assess the diagnostic value of the history and of additional investigations of patients with a transient loss of consciousness, and to compare the diagnostic interpretation of the history of these patients by different physicians.

Setting

Academic Hospital Leiden.

Design

Prospective.

Patients and methods

119 consecutive adult patients with a transient loss of consciousness were interviewed. All patients had an ECG, an EEG and laboratory tests. Patients younger than 65 years of age had an additional hyperventilation test. All were followed up for 15 months. 45 patients (38) received a final diagnosis of seizure and 74 patients (62) a diagnosis of syncope. The sensitivity, specificity and likelihood ratio were calculated of all significant findings. The details of the history were given to 2 general practitioners, 2 neurologists and 2 epileptologists. To compare the interrater agreement the kappa method was used.

Results

With a prior probability of a seizure of 25, the posterior probability was 94 if the patient was confused afterwards according to the eyewitness, and 6 if the patient was not confused. Epileptiform activity on the EEG gave a posterior probability of 73. The EEG could not exclude a seizure. The hyperventilation test was not more informative than a simple question about attacks of breathlessness. Between physicians disagreement about the diagnosis was substantial.

Conclusion

If a patient is confused after a transient loss of consciousness a seizure is more likely than a syncope.