Absence Semiologies
Authors: Blume Warren T. 
Published: July 2009

Factors Influencing Clinical Features of Absence Seizures. Sadleir LG, Scheffer IE, Smith S, Carstensen B, Carlin J, Connolly MB, Farrell K. Epilepsia 2008;49(12):2100–2107. PURPOSE: The clinical features of absence seizures in idiopathic generalized epilepsy have been held to be syndrome-specific. This hypothesis is central to many aspects of epilepsy research yet has not been critically assessed. We examined whether specific factors such as epilepsy syndrome, age, and state determine the features of absence seizures. METHODS: Children with newly presenting absence seizures were studied using video electroencephalography (EEG) recording. We analyzed whether a child's epilepsy syndrome, age, state of arousal, and provocation influenced specific clinical features of their absence seizures: duration, eyelid movements, eye opening, and level of awareness during the seizure. RESULTS: Seizures (509) were evaluated in 70 children with the following syndromes: Childhood absence epilepsy (CAE), 37; CAE plus photoparoxysmal response (PPR), 10; juvenile absence epilepsy (JAE), 8; juvenile myoclonic epilepsy (JME), 6; unclassified, 9. Seizure duration was associated with epilepsy syndrome as children with JME had shorter seizures than in other syndromes, independent of age. Age independently influences level of awareness and eye opening. Arousal or provocation affected all features except level of awareness. Specific factors unique to the child independently influenced all features; the nature of these factors has not been identified. DISCUSSION: The view that the clinical features of absence seizures have syndrome-specific patterns is not supported by critical analysis. We show that confounding variables profoundly affect clinical features and that syndromes also show marked variation. Variation in clinical features of absence seizures results from a complex interaction of many factors that are likely to be genetically and environmentally determined.

Childhood Absence Epilepsy: Behavioral, Cognitive, and Linguistic Comorbidities. Caplan R, Siddarth P, Stahl L, Lanphier E, Vona P, Gurbani S, Koh S, Sankar R, Shields WD. Epilepsia 2008 Nov;49(11):1838–1846. PURPOSE: Evidence for a poor psychiatric, social, and vocational adult outcome in childhood absence epilepsy (CAE) suggests long-term unmet mental health, social, and vocational needs. This cross-sectional study examined behavioral/emotional, cognitive, and linguistic comorbidities as well as their correlates in children with CAE. METHODS: Sixty-nine CAE children aged 9.6 (SD = 2.49) years and 103 age- and gender-matched normal children had semistructured psychiatric interviews, as well as cognitive and linguistic testing. Parents provided demographic, seizure-related, and behavioral information on their children through a semi-structured psychiatric interview and the child behavior checklist (CBCL). RESULTS: Compared to the normal group, 25% of the CAE children had subtle cognitive deficits, 43% linguistic difficulties, 61% a psychiatric diagnosis, particularly attention deficit hyperactivity disorder (ADHD) and anxiety disorders, and 30% clinically relevant CBCL broad band scores. The most frequent CBCL narrow band factor scores in the clinical/borderline range were attention and somatic complaints, followed by social and thought problems. Duration of illness, seizure frequency, and antiepileptic drug (AED) treatment were related to the severity of the cognitive, linguistic, and psychiatric comorbidities. Only 23% of the CAE subjects had intervention for these problems. CONCLUSIONS: The high rate of impaired behavior, emotions, cognition, and language and low intervention rate should alert clinicians to the need for early identification and treatment of children with CAE, particularly those with longer duration of illness, uncontrolled seizures, and AED treatment.