Abstracts

Rationale: After a first seizure, patients may be erroneously diagnosed as suffering from epilepsy, or the diagnosis may be missed, which can have serious psychosocial and socioeconomic consequences. In addition to the description of the first seizure, EEG findings may be useful in the diagnosis, but may also be misleading (Epilepsia 2006;47:9-13). The first EEG shows epileptiform abnormalities in only 25-56% of the patients clinically diagnosed with epilepsy, whereas repeating EEG measurements increases the likelihood of finding epileptiform abnormalities (J Neurol Neurosurg Psychiatry 2005;76:ii2-ii7). Particularly in patients with new onset seizures and normal initial EEGs, a recording after sleep-deprivation is employed, even though there is controversy about the actual efficacy of this activation procedure (Seizure 2000;9:580-584). In this study, we evaluate the diagnostic value and feasibility of 24h in-home EEG in patients evaluated for epilepsy, as compared to the standard procedure of a routine EEG- recording followed by an EEG after sleep-deprivation. Methods: In total, 100 first-seizure patients, aged 18 years or older, will be randomized to either a group who will have a standard EEG eventually followed by a sleep-deprived EEG, or a group having a standard EEG followed by an 24h in-home EEG. In-home EEGs are recorded using a dedicated portable amplifier (TMS-international). The diagnostic value, time-to-diagnosis, number of hospital visits, costs and satisfaction will be assessed. Patients will be followed for up to one year after the first seizure. Results: At present, fifteen first-seizure patients have been included, of which eight were assigned to the in-home group. None of the standard EEGs contained epileptiform discharges, whereas one of the sleep-deprived and one of the in-home EEGs contained epileptiform discharges. The number of hospital visits ranged from three to six and from four to five visits for the standard and in-home group respectively, whereas the time-to-diagnosis varied between 13 and 93 and 59 and 107 days. All patients were satisfied with the in-home EEG recording. Conclusions: In-home EEG in first-seizure patients seems feasible. However, the percentage of first-seizure patients with epileptiform discharges is low. Follow-up should demonstrate whether this is caused by the low sensitivity of the EEGs or by the low percentage of first-seizure patients eventually diagnosed with epilepsy. At present, the number of included patients is too limited to draw any other conclusions on the diagnostic value of 24h in-home EEG in first seizure patients. However, we expect to be able to draw further conclusions on the clinical relevance of 24h in-home EEG in first seizure patients when all patients are included.