Features Differentiating a Generalized Seizure from Vasovagal Syncope and Cardiac Syncope Due to Arrhythmia (Stokes-Adams Attack)
| Generalized seizure | Vasovagal syncope | Cardiac syncope due to arrhythmia | |
|---|---|---|---|
| Occurrence when sitting or lying | Common | Rare | Common |
| Occurrence during sleep | Common | Does not occur | May occur |
| Prodromal symptoms | May occur, with focal neurological symptoms, head turning, automatisms | Typical, with dizziness, sweating, nausea, blurring of vision, disturbance of hearing, yawning | Often none; palpitation may precede syncope in tachyarrhythmias |
| Focal neurological features at onset | May occur, and signify focal cerebral lesion | Never occur | Never occur |
| Tonic-clonic movements | Characteristic, occur within 30 s of onset | May occur after 30 s of syncope (secondary anoxic seizure) | May occur after 30 s of syncope (secondary anoxic seizure) |
| Facial colour | Flush or cyanosis at onset | Pallor at onset and after syncope | Pallor at onset, flush on recovery |
| Tongue biting | Common (lateral border) | Rare | Rare |
| Urinary incontinence | Common | May occur | May occur |
| Injury | May occur | Uncommon | May occur |
| After the attack | Confusion common | Nauseated and ‘groggy’ | Usually well |