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Case Reports
. 2021 Jun 11:6:185-188.
doi: 10.1016/j.cnp.2021.03.009. eCollection 2021.

Occurrence of hyperventilation-induced high amplitude rhythmic slowing with altered awareness after successful treatment of typical absence seizures and a network hypothesis

Simone Mattozzi  1 , Caterina Cerminara  2 , Maria A Sotgiu  3 , Alessandra Carta  1 , Antonella Coniglio  2 , Denis Roberto  2 , Delia M Simula  1 , Gian Luca Pruneddu  1 , Silvia Dell'Avvento  1 , S Sonia Muzzu  1 , Maria Fadda  1 , Giovanni M Luzzu  1 , Stefano Sotgiu  1 , Susanna Casellato  1
Affiliations
Case Reports

Occurrence of hyperventilation-induced high amplitude rhythmic slowing with altered awareness after successful treatment of typical absence seizures and a network hypothesis

Simone Mattozzi et al. Clin Neurophysiol Pract. .

Abstract

Background: Typical absence seizures (AS) are epileptic phenomena typically appearing in children 4-15 years of age and can be elicited by hyperventilation (HV). Hyperventilation-induced high-amplitude rhythmic slowing (HIHARS) represents a paraphysiological response during HV and may manifest with alteration of awareness (HIHARSAA). To date, HIHARSAA has mostly been described in patients without epilepsy.

Aim: To describe five patients with treatment-responsive typical AS who, after becoming seizure free, presented with HIHARSAA.

Methods: By using video-electroencephalographic recording (Video-EEG), we describe differential clinical characteristics and ictal electrophysiological patterns of both typical AS and HIHARSAA.

Results: We demonstrate that when HIHARSAA occurs in patients with typical AS there is a temporal window between the two phenomena. This suggests that the presence of typical AS precludes the appearance of HIHARSAA.

Conclusions: We hypothesize that alkalosis and dysfunction of the same neural network are involved in both typical AS and HIHARSAA and that their distinct electroclinic manifestations are due to the involvement of different ion channels.

Significance: A better understanding of the characteristics of typical AS and HIHARSAA and of the role of alkalosis in both, can help avoiding misdiagnosis and identifying more suitable therapies for typical AS.

Keywords: Alkalosis; HIHARS; Hyperventilation; Loss of awareness; Typical absence.

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Figures

Fig. 1
Fig. 1
The images show ictal electroencephalograms demonstrating typical AS and HIHARSAA patterns. Panel A shows the typical AS patterns of patients 1 and 2 respectively. Panel B shows the respective HIHARSAA patterns of patients 1 and 2. The red lines and yellow ones show the similar frequencies, in both phenomena. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
See this image and copyright information in PMC

References

    1. Barker A., Ng J., Rittey C.D.C., Kandler R.H., Mordekar S.R. Outcome of children with hyperventilation-induced high-amplitude rhythmic slow activity with altered awareness. Dev. Med. Child Neurol. 2012;54:1001–1005. http://www.ncbi.nlm.nih.gov/pubmed/22712871 Available from. - PubMed
    1. Bomben V.C., Aiba I., Qian J., Mark M.D., Herlitze S., Noebels J.L. Isolated P/Q calcium channel deletion in layer VI corticothalamic neurons generates absence epilepsy. J. Neurosci. 2016;36:405–418. http://www.jneurosci.org/cgi/doi/10.1523/JNEUROSCI.2555-15.2016 Available from. - DOI - PMC - PubMed
    1. Buchhalter J. Treatment of childhood absence epilepsy-an evidence-based answer at last! Epilepsy Curr. 2011;11:12–15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3063575/ Available from. - PMC - PubMed
    1. Epstein M.A., Duchowny M., Jayakar P., Resnick T.J., Alvarez L.A. Altered responsiveness during hyperventilation-induced EEG slowing: a non-epileptic phenomenon in normal children. Epilepsia. 1994;35:1204–1207. http://www.ncbi.nlm.nih.gov/pubmed/7988512 Available from. - PubMed
    1. Glauser T.A., Cnaan A., Shinnar S., Hirtz D.G., Dlugos D., Masur D. Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy. N. Engl. J. Med. 2010;362:790–799. https://pubmed.ncbi.nlm.nih.gov/20200383/ Available from. - PMC - PubMed

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