Clinical Aspects of the Diagnosis of Epileptic Seizures

The clinician must investigate and corroborate key features of the history that help to better characterize seizures while distinguishing epileptic seizures from nonepileptic events. The most common nonepileptic paroxysmal events during childhood and adolescence are syncope, psychogenic nonepileptic events (PNES), pallid and cyanotic breath holding spells, reflux/Sandifer syndrome, self-gratification disorders, and paroxysmal nonepileptic motor disorders of sleep among others.

History and Physical Examination Findings That Help Characterize Seizures

Predisposing factors	Pre-ictal semiology	Seizure semiology	Postictal semiology
Family history of seizures or epilepsy Cognitive and developmental deficits Precipitating events (trauma, fever, toxins, sleep deprivation, hyperventilation, flashing lights, etc) Preexisting structural brain lesion	Aura (vision of lights or colors, epigastric rising sensation, etc) Behavioral changes (ie, behavioral arrest/unresponsiveness or period of confusion) Automatism (pill rolling, picking, lip smacking) Tiredness Irritability Lack of appetite	Order of appearance and duration of every semiologic component Level of consciousness (ability to understand) Motor activity (clonic, tonic, tonic clonic) Sensory abnormality Predominant side of occurrence of every component Vocal output (cries, grunts, etc) Stereotypical facial expressions (facial slackening, eyelid fluttering, staring, or eye deviation) Autonomic features (tachycardia, pallor, sweating, piloerection) Incontinence Respiration pattern Autonomic features (tachycardia, pallor, sweating, piloerection) Falls or loss of tone Total duration Presence of rhythmicity and evolution in frequency of event	Sleepiness Amnesia Confusion Headaches Partial paralysis Muscular pain Behavioral changes Predominant side of every component Presence of injury secondary to the seizure episode

The clinician should investigate these features in every patient with a suspected first unprovoked seizure.

Main Differential Features of Seizures, Syncope, and Psychogenic Nonepileptic Seizures

Events in the history that are suggestive of	Before the event	During the event	After the event
Epileptic seizures	Sleep deprivation Toxic exposure Toxic withdrawal Exposure to lights or sounds Sensory aura Epigastric rising sensation Hallucination	Stereotyped Lack of response to stimulia Automatisms Eyes generally opened; if closed, there is no resistance to passive openinga Hypersalivation Incontinencea Short duration (1 min or less)a Vocalization, if present, consists of simple sounds (crying)	Prolonged period of altered consciousness (sleepiness, confusion, etc) until complete recoverya Relatively frequent traumatic injurya Tongue biting relatively frequent and present in the lateral side of the tonguea There is no recall of the episode or the peri-ictal period Breathing is frequently deep and prolongeda
Syncope	Emotional stress Prolonged standing Dehydration, hunger, pain Carotid sinus stimulation Elevated intrathoracic pressure (micturition, cough)	Pallor Sweat Repeated movements, if present, occur once on the floor, not while standing Brief loss of consciousness Incontinence may occur	Uncommon postictal headache or postictal confusion Rapid and complete return to baseline Infrequent traumatic injury Recall of the period around the episode Tongue biting typically midline or at the tip of the tongue
Psychogenic nonepileptic events	Appearance in a particular context (presence of witnesses, presence of significant others, emotions) Trance, dreamlike state Distortion of perception Sensation of death Gradual onset Sometimes the episode can be induced with certain maneuvers	Out-of-phase motor activity Vocalization of complex and purposeful sounds (words) Forceful closure of the eyes with resistance to passive eye opening Fluctuating course Violent movements Long duration (generally more than 1 minute) Trashing and grabbing behavior Pelvic thrusting Semipurposeful, goal-directed movements Confused staring Response to stimuli Directed rage	Inconsistent state of altered consciousness (sleepiness, confusion, etc) Shallow and rapid breathing Recall of the episode Correct but partial and feeble motor responses

^aTypical characteristics of generalized motor seizures.

 

References:

1. Sansevere AJ, Avalone J, Strauss LD, Patel AA, Pinto A, Ramachandran M, Fernandez IS, Bergin AM, Kimia A, Pearl PL, Loddenkemper T. Diagnostic and Therapeutic Management of a First Unprovoked Seizure in Children and Adolescents With a Focus on the Revised Diagnostic Criteria for Epilepsy. J Child Neurol. 2017 Jul;32(8):774-788. [Medline]
2. Gavvala JR, Schuele SU. New-Onset Seizure in Adults and Adolescents: A Review. JAMA. 2016 Dec 27;316(24):2657-2668. [Medline]
3. Alessi N, Perucca P, McIntosh AM. Missed, mistaken, stalled: Identifying components of delay to diagnosis in epilepsy. Epilepsia. 2021 Jul;62(7):1494-1504. [Medline]

 

Created Oct 14, 2021.