Characteristic | Generalized seizure tonic-clonic | Pseudoseizure | Syncope |
Circumstances |
Situation | Awake or sleep | Awake | Usually upright; any position if cardiogenic |
Precipitating factors | Sleep loss, alcohol withdrawal, flashing lights | Emotion | Emotion, injury, heat, crowds; none if cardiogenic |
Presence of others | Variable | Usual | Variable |
Motor phenomena |
Vocalization | At onset, if any | During course | None |
Location of motor component (if present) | Proximal limb | Proximal limb | None |
Generalized motor | Tonic, then clonic | Tonic; flailing; struggling or thrashing, or both | Usually atonic; if syncope lasts >20 seconds: tonic, then clonic |
Tonic posture | Partial flexion or straight | Opisthotonic | - |
Head movements | To one side or none | Side to side | - |
Clonus/limb jerks | Bilaterally synchronous | Asynchronous | Bilaterally synchronous |
Purposeful movements | Absent | Occasional, including avoidance | Absent |
Biting | Tongue, inside mouth | Lips, arms, other people | Tongue biting rare |
Babinski's sign | Present | Absent | Absent |
Autonomic features |
Micturition | Frequent | Rare | Occasional |
Eyes | Open | Closed | Open |
Pupils | Dilated or hippus during attacks | Normal | Dilated |
Colour | Cyanotic or grey | Rubor or normal | Pale |
Pulse | Rapid, strong | Normal | Slow if vasovagal, weak if vasodepressor; that of arrhythmias if cardiogenic |
Timing |
Usual duration | 1 to 5 min | 5 to 60 min | 1 to 2 min |
Onset | Sudden | Gradual | Gradual; possibly sudden if cardiogenic |
Sequence of symptoms | Stereotyped | Variable | Stereotyped |
Termination | Spontaneous | Spontaneous or induced by supraorbital pressure, suggestion | Rapid |
Sequelae |
Injury | Frequent, mild; scalp, face, common | Rare, but multiple bruises possible; scalp, face, rare | If sudden onset |
Postictal | Tired, confused, sleepy | Alert, emotional outburst | Regains consciousness in 2 to 3 min; alert but tired |