Diagnostic Considerations
Panic disorder
This may be associated with autonomic phenomena and anxiety similar to those observed in the simple partial (focal aware) phase of a temporal lobe seizure. However, unlike temporal lobe epilepsy, which lasts seconds to 2 minutes, panic attacks last several minutes (usually >10 min).
Migraine headache
Migraine headache is another paroxsymal neruologic disorder that sometimes can be mistaken for seizures (and vice versa), as it also has an aura and can produce various neurologic signs and symptoms if complex or complicated. Interestingly, two seizure medications are FDA-approved to prevent migraines: divalproic acid and topiramate.
Excessive daytime somnolence
This may be due to a sleep-related breathing disorder or narcolepsy. It causes episodes of loss of time due to falling asleep frequently.
Non-epileptic seizures
Approximately 10–30% of patients with psychogenic seizures also have epileptic seizures. The diagnosis of psychogenic seizure needs to be made after a thorough evaluation as some seizures that are atypical may be true seizures. The importance of diagnosing nonepileptic seizures is important as psychogenic seizures do not respond to antiepileptic events and require psychiatric intervention.
Frontal lobe epilepsy
Frontal lobe complex partial seizures (focal impaired awareness seizures) have certain distinct characteristics. They appear in clusters of many brief seizures with rapid onset and ending and minimal, if any, postictal state. Prominent features include bizarre behavioral changes such as vocalizations and complex motor and sexual automatisms. However, distinguishing frontal lobe complex partial seizures from those of the temporal lobe based solely on clinical features may be difficult; EEG is invaluable for localization.
Absence epilepsy
Generalized absence seizures have an abrupt onset with no aura, usually last less than 30 seconds, and have no postictal state. EEG in absence shows generalized, bilaterally synchronous spike-and-wave discharges and photosensitivity. Complex partial seizures usually are preceded by a distinct aura, last longer than a minute, and have a period of postictal confusion. EEG shows focal spikes in complex partial seizures.
Other considerations
Epilepsy occurs in all age groups, but it has been underrecognized in elderly persons. Epilepsy in elderly persons may not be as dramatic and often may present as confusion or memory lapses. The index for suspicion should be low, as patients are often misdiagnosed and not treated appropriately.
Differential Diagnoses
