History
History remains the key in obtaining a correct diagnosis in patients with first seizure in adulthood. The detailed description of the actual episode in question is particularly important. The description should be obtained separately from the patient and from a caregiver who has witnessed the event.
The patient may be able to report a warning or aura and the feeling after the seizure. The presence of an aura, by definition, makes the diagnosis of a localization-related epilepsy, because auras are “simple partial” seizures with subjective symptoms. However, not every warning symptom is an aura.
Generally speaking, in order to be considered auras, the symptoms should be brief (seconds) and followed, at least some of the time, by more definite seizure. Auras widely vary but tend to be stereotyped in a given patient. Some (eg, déjà-vu, fear, epigastric sensation, lateralized somatosensory or visual phenomena) are very specific and even localizing; others are not (eg, indescribable sensation, whole body sensations, other vague symptoms like dizziness). The patient may not be able to describe the symptoms during the seizure, which speaks to loss of awareness, but says that the “next thing I know is coming to.”
The caregivers or witnesses should then describe what they observe; having the caregivers mimic the types of movements or behaviors they see during the attacks may be helpful. Occasionally, the best witnesses are not present; this may require a telephone call.
The following information should be obtained in the history:
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Record the patient's age.
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If a family history of seizures is noted, determine the clinical epilepsy syndrome of the affected family member.
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Ask about a history of any previous provoked seizure.
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Determine if the first seizure was status epilepticus.
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Ask the time of day of the seizure occurrence.
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Determine whether there is a history of postictal confusion, incontinence, and occurrence out of sleep.
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Psychogenic nonepileptic attacks (PNEAs) are the most common nonepileptic events seen in referral epilepsy centers but should only be considered in the setting of recurrent episodes. [2]
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Seek a possible cause (see Etiology).
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Consider other paroxysmal neurologic events and identify seizure mimics, such as syncope, transient ischemic attack, transient global amnesia, migraine, sleep disorder, movement disorder, and vertigo. [28]
In syncope, several historical features can be helpful. When an accurate description is missing (eg, unwitnessed event), the distinction between syncope and seizures can be difficult, because it is based on history alone; however, several symptoms are helpful in aiding the diagnosis. [27, 29] These include the circumstances of the attacks, because the most common mechanism for syncope (vasovagal response) is typically triggered by known precipitants (eg, pain such as inflicted by medical procedures, emotions, cough, micturition, hot environment, prolonged standing, exercise).
Other historical features that favor syncope include “presyncopal” prodromes (eg, vertigo, dizziness, lightheadedness, chest pain, nausea), as well as age and a history of cardiovascular disease. Historical features that favor seizures include tongue biting, head turning, posturing, urinary incontinence, cyanosis, prodromal déjà-vu, and postictal confusion. [27, 29] A point system using most of these features was designed, with a reported 94% sensitivity and specificity for the diagnosis of seizures. [29]
Physical Examination
The neurologic examination should be directed at finding clinical evidence of a focal brain lesion, and a general physical examination should be performed to exclude a non-neurologic cause of the seizure. [30]
Pay attention to the presence of signs traumatic injuries to any part of the body, especially a tongue bite, which is highly specific in epileptic seizures. [31, 32]
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An electroencephalogram (EEG) recording of a temporal lobe seizure. The ictal EEG pattern is shown in the rectangular areas.
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An electroencephalogram (EEG) recording from a patient with primary generalized epilepsy. A burst of bilateral spike and wave discharge is shown in the rectangular area.
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An electroencephalogram (EEG) recording of a seizure from a subdural array in a patient evaluated for epilepsy surgery. The subdural electrodes record from the left anterior temporal (LAT), left middle temporal (LMT), and left posterior temporal (LPT) regions. The EEG seizure pattern is seen best in bipolar EEG channels LAT 3-4 and LMT 3-4 (rectangular areas).
