Typical Absence Status in Adults: Diagnostic and Syndromic Considerations

Abstract

Summary: Purpose: To study the electroclinical features of typical absence status (TAS) in adults with syndromes of idiopathic generalized epilepsies (IGEs).Methods: Twenty-one patients with one or more spells of TAS were identified among 136 consecutive adult patients with IGEs. All patients with TAS had comprehensive electroclinical investigations and EEG or video-EEG recorded absences.Results: TAS occurred in 24.4% of 86 patients who had IGEs with typical absences alone or in combination with other seizures presisting in adult life. The prevalence of TAS appeared to be syndrome related, ranging from as high as 57.1% in perioral myoclonia with absences and 46.2% in "phantom" absences with GTCS to as low as 6.7% in juvenile myoclonic epilepsy. A varying degree of impairment of cognition was the cardinal clinical symptom shared in all TAS, but corresponding syndromes of IGE were often betrayed by other symptoms such as eyelid or perioral myoclonia. In phantom absences with GTCS, TAS was more numerous (p S 0.05) and more frequently the first overt seizure type (p = 0.006) than in any other IGE. Only in the syndrome of eyelid myoclonia with absences, TAS was always situation related, mainly as a result of antiepileptic drug discontinuation.Conclusions: The clinical EEG semiology and prevalence of TAS appear to be syndrome related with the highest prevalence in the syndromes of perioral myoclonia with absences and phantom absences with GTCS (p = 0.0024). Key Words:Typical absence status-Nonconvulsive status epilepticusIdiopathic generalized epilepsies-Epileptic syndromesAdults.Absence status is the commone3t form of nonconvulsive status epilepticus, ranging from 53 to 94% in different studies (1-5). It is manifested with prolonged confusional states of varying severity and EEG continuous or repetitive generalized discharges of spikes, multiple lowing. classification of absence status:4. Absence status epilepticus occumng in other epileptic syndromes: progressive myoclonic epilepsies, electrical status epilepticus during slow sleep, Landau-Kleffner syndrome, metabolic or degenerative generalized epilepsies, electrographic gtatus. spikes, and slow waves. Shorvon (6,7) proposed the folTypical (idiopathic) absence status epilepticus occurring in the syndromes of idiopathic generalized epilepsies (IGEs). The EEG discharges are of >2.5 Hz. Atypical (cryptogenic and symptomatic) absence status epilepticus, mainly found in epilepsies, such as the Lennon-Gastaut syndrome. The EEG discharges are slow and <2.5 Hz. De novo absence status epilepticus of late onset, arising de novo in adults without a history of previous epileptic seizures, mainly as the result of drug discontinuation.Although it is well documented in the literature (1-16), absence status is frequently overlooked. It is erroneously considered as complex partial status or other conditions unrelated to epileptic seizures, such as dementia, psychogenic or other behavior disorder (1,10, 12).Furthermore, absence status is usually studied in a unitary fashion without ...

The hippocampus participates in a pharmacological rat model of absence seizures

“…The degree of hippocampal and limbic involvement during SWDs may depend on absence seizure types, such as atypical absence or absence status epilepticus (Agathonikou et al, 1998). Hippocampal involvement may be a factor that explain the variability of cognitive and memory deficits among patients with absence seizures (Jackson et al, 2013).…”

“…Seizures commonly manifest between the age of four years and early adolescence and are more prevalent in females. More common in adults are prolonged states of confusion with continuous and generalized EEG discharges known as absence status epilepticus (Agathonikou et al, 1998). The behavioral hallmark of absence seizures is a brief loss of awareness and staring spells with an abrupt onset and offset.…”

Behavioral Manifestations of Nonconvulsive Status Epilepticus

“…However, features previously thought to differentiate between ASE and CPSE may be seen in either type: total unresponsiveness and cyclical behavioral changes such as speech arrest, stereotyped nonlateralized automatisms alternating with phases of reactive automatisms and partial speech (36, 40 -42). With both ASE and CPSE, there may be hallucinations, agitation, and aggressive and violent behavior (42)(43)(44)(45), and there is great overlap of clinical phenomenology between GNSE and CPSE (17,21,24,25,(35)(36)(37)(38)(39)(40)(41)(42)(43)(44). The sections below delineate the behavioral features of patients with seizures in NCSE, with tables emphasizing distinguishing characteristics (see Table 5 for the results of one such study).…”

“…Typical absence status epilepticus (TAS) is recognized at onset in 19% of patients, but is often misdiagnosed as depression, CPSE, postictal confusion, posttraumatic amnesia, toxic states, hysterical behavior, or schizophrenia, or is ignored (43,45). Seventyfive percent of cases occur before the age of 20 years.…”

“…Many synonyms have been used in describing typical and atypical ASE: petit mal status; epileptic twilight state, minor epileptic status, spike-wave stupor, prolonged epileptic twilight state, epilepsia minoris continua, absence continue, status pyknolepticus, ictal psychosis, and état de mal à l' expression confusionelle (45)(46)(47)(48)(49)(50)(51)(52).…”