Abstracts

Rationale: JME is a widely recognized idiopathic generalized epilepsy syndrome and is thought to be easily diagnosed. As in most epilepsy syndromes, diagnostic criteria are somewhat vague. There is variation in the quoted age of seizure onset, seizure types, EEG findings and presence/absence of neurological and intellectual deficits. We attempted to collate the criteria used to diagnose JME by a sample of Canadian adult and pediatric neurologists with special expertise in epilepsy and an international group of epilepsy experts .Methods: A questionnaire was sent to a convenience sample of Canadian adult epileptologists and pediatric neurologists who focus on epilepsy. Our questionnaire asked if certain clinical and EEG findings were required for the diagnosis of JME and the youngest age of onset. The same questionnaire was completed by a group of epilepsy experts from around the world who were attending a meeting about JME in May 2011. Results: Responses were received from 43 neurologists (32 child neurologists and 11 adult epileptologists) from nearly all major centres in Canada the response rate was >90%. 25 epilepsy experts also responded. The exact questions and overall responses are noted below. To diagnose JME: 1. Do you require a history of myoclonus ? Yes N= 62 No N= 7 2. Is myoclonus as the only seizure type + EEG bursts of fast-wave sufficient? Yes 48 No 20 3. Is a history of myoclonus + a single generalized tonic-clonic seizure (GTC) + a typical EEG sufficient? Yes 69 No 0 4. Do the GTCs need to be in the early morning? Yes 9 No 60 5. Must the EEG show generalized fast spike and wave? Yes 34 No 35 6. If the EEG shows only bursts of classical 3 hz spike and wave can you diagnose JME? Yes 40 No 28 7. Does the EEG background need to be normal? Yes 60 No 9 8. Does the neurological examination need to be normal? Yes 56 No 13 9. Does the intelligence need to be normal? Yes 42 No 27 10. Do you require an MRI before diagnosing JME? Yes 6 No 63 11. What is the earliest age JME can be diagnosed? Mean 9 2.3 years, range 2-14 years. Adult neurologists were more likely to require an MRI before diagnosis (p=0.01). All of the international epilepsy experts required myoclonus for the diagnosis (p=0.04). Responses to all other questions were similar between groups. Conclusions: There was complete agreement that the diagnosis of JME can be made with history of myoclonus + a single generalized tonic-clonic seizure (GTC) + a typical EEG. Otherwise there was significant variation for each diagnostic criterion, even including the need for myoclonus! This variability was seen in Canada and around the world. The process for defining syndromes with necessary criteria needs strengthening if optimal decisions about investigation, treatment and research are to be based on syndrome diagnosis.