From the Guidelines
Approximately 30-50% of patients with a first unprovoked seizure will have a recurrent seizure within 2 years. The risk of recurrence varies significantly based on individual factors such as the presence of structural brain abnormalities, abnormal EEG findings, family history of epilepsy, or the seizure occurring during sleep 1.
Factors Influencing Recurrence Risk
- The presence of structural brain abnormalities
- Abnormal EEG findings
- Family history of epilepsy
- Seizure occurring during sleep Patients with normal neurological examinations, normal brain imaging, and normal EEG results have the lowest recurrence risk (around 30%), while those with multiple risk factors may have recurrence rates approaching 70% 1.
Management Approach
Because of this relatively high non-recurrence rate, antiepileptic medication is typically not prescribed after a single unprovoked seizure unless specific risk factors are present 1. Instead, most neurologists recommend careful monitoring and follow-up, with medication consideration only if a second seizure occurs or if risk factors strongly suggest high recurrence probability.
Considerations for Treatment
The strategy of waiting until a second seizure before initiating antiepileptic medication is considered appropriate, as outcomes at 5 years are no different whether treatment is initiated within days to weeks after a seizure or later 1. For patients with a first unprovoked generalized seizure, it would be necessary to treat 14 patients to prevent a single seizure recurrence within the first 2 years 1.
From the Research
First-Time Seizures
- The exact percentage of first-time seizures is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
- However, it is mentioned that approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures, and most achieve that remission shortly after starting antiepileptic drug treatment 2, 4.
- Almost 10% of people will experience at least one seizure over a lifetime, according to a study published in 2019 3.
Antiepileptic Drug Efficacy
- The efficacy of antiepileptic drugs in treating generalized epileptic seizures was compared in a systematic review and network meta-analyses, which found that lamotrigine, levetiracetam, and topiramate are as effective as valproate for treating generalized tonic-clonic, tonic, and clonic seizures 5.
- Another study found that levetiracetam performed significantly better than both current first-line treatments carbamazepine and lamotrigine for individuals with partial seizures 4.
- The most commonly reported adverse events across all drugs were drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness, and rash or skin disorders 2, 4.
Treatment Outcomes
- Network meta-analysis showed high-certainty evidence that for the primary outcome 'time to treatment failure', lamotrigine performs better than most other treatments for individuals with focal seizures 2.
- For people with generalised onset seizures, evidence was more limited and of moderate certainty, but no other treatment performed better than first-line treatment sodium valproate 2.
- The earliest licensed treatments, such as phenytoin and phenobarbitone, performed better than other treatments for individuals with focal seizures in terms of 'time to first seizure' 2, 4.