1. Answer C. (MN-60) Lifetime risk of recurrent seizures is not known for this particular patient at the time of first presentation. However, in prospective studies, recurrence rates at 2 years after first-time seizure vary between 25% and 51%, depending on many factors including if antiseizure medications are started. However, it is not established starting antiseizure medication after a single unprovoked seizure improves long-term prognosis. In general, if a patient has two seizures then medications should be started as the risk of recurrent events is high.

2. Answer A. (MN-60) “Typical” absence seizures usually and have rapid onset and offset of behavioral arrest and last less than 20 seconds. “Atypical” absence seizures have a similar EEG pattern; however, they have clinical features including protracted onset, longer duration, and concomitant abnormal motor movements or loss of motor tone; they are usually seen in the broader context of a neurodevelopmental disorder. The other seizure types listed generally do not have a characteristic slow spike-and-wave EEG pattern.

3. Answer D. (MN-60) Temporal intermittent rhythmic delta activity (TIRDA) is a pattern commonly associated with TLE. Lateralized interictal sharp and spike waves, as well as focal slowing, are often seen in TLE; however, they are not particularly specific. Wicket spikes are benign EEG variants localized to the temporal lobe that are not clearly associated with epilepsy. Rhythmic midtemporal theta of drowsiness is a normal EEG variant seen in some healthy adults, and K-complexes are seen in healthy adults during stage 2 sleep.

4. Answer B. (MN-60) This patient has a specific self-limited focal epilepsy syndrome: benign epilepsy with centrotemporal spikes, also known as benign Rolandic epilepsy; the description above has many of the characteristic clinical features, and the EEG pattern in this condition shows centrotemporal spikes on EEG.

5. Answer B. (MN-60) The EEG shows generalized frontally predominant 3- to 4-Hz spike and wave discharges consistent with a generalized epilepsy syndrome. West syndrome is a childhood epilepsy syndrome that begins in the infantile period. Temporal lobe epilepsy will show focal or lateralized EEG patterns and generally have a lesion visible on MRI.

6. Answer C. (MN-61) Prospective studies of patients with newly diagnosed epilepsy show that, when an appropriate drug is prescribed, about 50% will become seizure free on the first agent (assuming tolerability). If the first drug fails, an additional 10% will become seizure free. However, 30% to 40% of patients will remain refractory to subsequent medication trials.

7. Answer D. (MN-61) This drug has the most complicated pharmacokinetics of all anticonvulsants. The zero-order kinetics are problematic as this usually occurs within the therapeutic range, thereby often resulting in high levels (with consequent toxicity) or low levels (with potential for breakthrough seizures) after small changes in dose (or absorption). All other drugs for epilepsy exhibit first-order kinetics within the therapeutic range, such that dose is directly proportional to plasma concentration. Phenytoin is also a strong inducer of hepatic enzymes, resulting in increased metabolism of many coadministered drugs. Phenytoin is also highly protein bound, such that the free (active) portion can be unexpectedly high in certain conditions, such as when other highly protein-bound drugs are coadministered (notably valproic acid), when serum albumin is low, or in severe renal failure.

8. Answer E. (MN-61) When used at appropriate doses for the correct epilepsy syndrome, no drug is clearly known to be more effective than another at seizure control in a population of patients (although in individual patients responsiveness to specific drugs certainly occurs). For this reason, other properties of the anticonvulsant drug are used in choosing the most appropriate agent. In addition to the above properties, long-term safety may be a concern (thereby limiting the use of felbamate and phenytoin unless other options have failed). Speed of onset may be a factor particularly when seizures are frequent and debilitating; drugs such as lamotrigine and topiramate usually require several weeks of titration before reaching minimally effective doses, whereas levetiracetam, gabapentin, zonisamide, carbamazepine, oxcarbazepine, and eslicarbazepine can take effect very quickly.

9. Answer B. (MN-61) Most drugs for epilepsy have some effect on the metabolism of oral contraceptives, resulting in decreased efficacy. Only levetiracetam, gabapentin, pregabalin, and valproic acid have no effect. Many drugs, including oxcarbazepine, clobazam, and topiramate have less effect due to weaker enzyme induction; however, care must be taken especially at higher anticonvulsant doses.