Managing first-time seizures and epilepsy often requires consultation with a neurologist or epileptologist for diagnosis and subsequent management, including when medical treatment fails or in determining whether patients may benefit from surgery. However, given the high prevalence of epilepsy and even higher incidence of a single seizure, family physicians contribute significantly to the management of these patients. The main issues are managing a first-time seizure, making the diagnosis, establishing a treatment plan, and exploring triggers and mitigating factors.
Seizure vs epilepsy
All patients with epilepsy experience seizures, but not every person who experiences a seizure has (or will develop) epilepsy. Nearly 10% of the population has one seizure during their lifetime, whereas the risk for epilepsy is just 3%.1 Therefore, a first-time seizure may not herald epilepsy, defined as repetitive (≥ 2) unprovoked seizures more than 24 hours apart.2 Seizures can be provoked (acute symptomatic) or unprovoked; a clear distinction between these 2 occurrences—as well as between single and recurrent seizures—is critical for proper management. A close look at the circumstances of a first-time seizure is imperative to define the nature of the event and the possibility of further seizures before devising a treatment plan.
Provoked seizures are due to an acute brain insult such as toxic-metabolic disorders, concussion, alcohol withdrawal, an adverse effect of a medication or its withdrawal, or photic stimulation presumably by disrupting the brain’s metabolic homeostasis or integrity. The key factor is that provoked seizures always happen in close temporal association with an acute insult. A single provoked seizure happens each year in 29 to 39 individuals per 100,000.3 While these seizures typically occur singly, there is a small risk they may recur if the triggering insult persists or repeats.1 Therefore, more than 1 seizure per se may not indicate epilepsy.3
Unprovoked seizures reflect an underlying brain dysfunction. A single unprovoked seizure happens in 23 to 61 individuals per 100,000 per year, often in men in either younger or older age groups.3 Unprovoked seizures may occur only once or may recur (ie, evolve into epilepsy). The latter scenario happens in only about half of cases; the overall risk for a recurrent seizure within 2 years of a first seizure is estimated at 42% (24% to 65%, depending on the etiology and electroencephalogram [EEG] findings).4 More specifically, without treatment the relapse rate will be 36% at 1 year and 47% at 2 years.4 Further, a second unprovoked seizure, if untreated, would increase the risk for third and fourth seizures to 73% and 76%, respectively, within 4 years.3
Evaluating the first-time seizure
Ask the patient or observers about the circumstances of the event to differentiate provoked from unprovoked onset. For one thing, not all “spells” are seizures. The differential diagnoses may include syncope, psychogenic nonepileptic events, drug intoxication or withdrawal, migraine, panic attacks, sleep disorders (parasomnia), transient global amnesia, concussion, and transient ischemic attack. EEG, neuroimaging, and other relevant diagnostic tests often are needed (eg, electrocardiogram/echocardiogram/Holter monitoring to evaluate for syncope/cardiac arrhythmia). Clinically, syncopal episodes tend to be brief with rapid recovery and no confusion, speech problems, aura, or lateralizing signs such as hand posturing or lip smacking that are typical with focal seizures. However, cases of convulsive syncope can be challenging to assess without diagnostic tests.
True convulsive seizures do not have the variability in clinical signs seen with psychogenic nonepileptic events (eg, alternating body parts involved or direction of movements). Transient global amnesia is a rare condition with no established diagnostic test and is considered a diagnosis of exclusion, although bitemporal hyperintensities on magnetic resonance imaging (MRI) may appear 12 to 48 hours after the clinical episode.5 Blood work is needed in patients with medical issues treated with multiple medications to evaluate for metabolic derangements; otherwise, routine blood work provides minimal information in stable patients.
Region-specific causes. Neurocysticercosis is common in some regions, such as Latin America; therefore, attention should be paid to this aspect of patient history.
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