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. 2020 Oct 6;95(14):e2009-e2015.
doi: 10.1212/WNL.0000000000010470. Epub 2020 Aug 19.

Absence-to-bilateral-tonic-clonic seizure: A generalized seizure type

Sándor Beniczky  1 , Guido Rubboli  2 , Athanasios Covanis  2 , Michael R Sperling  2
Affiliations

Absence-to-bilateral-tonic-clonic seizure: A generalized seizure type

Sándor Beniczky et al. Neurology. .

Abstract

Objective: To test the hypothesis that absence seizures can evolve to generalized tonic-clonic seizures, we documented electroclinical features of this novel seizure type.

Methods: In 4 large video-EEG databases, we identified recordings of seizures starting with impaired awareness that, without returning to baseline interictal state, evolved to generalized tonic-clonic seizures. We extracted the detailed semiologic and electrographic characteristics of these seizures, and we documented the clinical background, diagnoses, and therapeutic responses in these patients.

Results: We identified 12 seizures from 12 patients. All seizures started with a period of impaired awareness and bursts of generalized spike or polyspike and slow-wave discharges, the hallmark of absence seizures. Without returning to baseline, the nonmotor (absence) phase was followed by tonic-clonic convulsions. We called this novel generalized seizure type absence-to-bilateral-tonic-clonic seizure. Most patients had idiopathic generalized epilepsies, although with a high incidence of unusual features and poor therapeutic response.

Conclusions: Absence-to-bilateral-tonic-clonic seizures are a novel generalized seizure type. Clinicians should be aware of this seizure for correctly diagnosing patients. This novel seizure type may further elucidate generalized ictogenesis.

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Figures

Figure 1
Figure 1. EEG recording (patient 6) showing the transition from the absence to the tonic phase of the ABTC seizure
The 2 channels in green are surface EMG recorded from the left and right deltoid muscles (EMG 1/2). The generalized spike-wave bursts continue while the tonic muscle activity builds up. ABTC = absence-to-bilateral-tonic-clonic.
Figure 2
Figure 2. EEG recording (patient 10) showing the transition from the absence to the tonic phase of the ABTC seizure
The 6 channels in green are surface EMG recorded from the left and right deltoid (EMG 1/2), brachial biceps (EMG 3/4), and anterior tibial (EMG 5/6) muscles. The generalized spike-wave bursts are gradually replaced by evolving ictal rhythm (low-amplitude fast activity). ABTC = absence-to-bilateral-tonic-clonic.
See this image and copyright information in PMC

References

    1. Glauser T, Ben-Menachem E, Bourgeois B, et al. . Updated ILAE evidence review of antiepileptic drug efficacy and effectiveness as initial monotherapy for epileptic seizures and syndromes. Epilepsia 2013;54:551–563. - PubMed
    1. Fisher RS, Cross JH, French JA, et al. . Operational classification of seizure types by the International League Against Epilepsy: position paper of the ILAE Commission for Classification and Terminology. Epilepsia 2017;58:522–530. - PubMed
    1. Tatum WO, Rubboli G, Kaplan PW, et al. . Clinical utility of EEG in diagnosing and monitoring epilepsy in adults. Clin Neurophysiol 2018;129:1056–1082. - PubMed
    1. Lüders H, Lesser RP, Dinner DS, Morris HH III. Generalized epilepsies: a review. Cleve Clin Q 1984;51:205–226. - PubMed
    1. Panayiotopoulos CP. The Epilepsies: Seizures, Syndromes and Management. Oxfordshire: Bladon Medical Publishing; 2005. - PubMed

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