Höller Y, Sciarrone A, Thomschewski A, Gerner N (2019) Adult-Onset Epilepsy in Klinefelter Syndrome? Cognitive and Neurophysiological Evaluation of a 56-Year-Old Man. Int J Rare Dis Disord 2:009. doi.org/10.23937/2643-4571/1710009


© 2019 Höller Y, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

CASE REPORT | OPEN ACCESS DOI: 10.23937/2643-4571/1710009

Adult-Onset Epilepsy in Klinefelter Syndrome? Cognitive and Neurophysiological Evaluation of a 56-Year-Old Man

Yvonne Höller1,2* Dipl.-Ing., Adriana Sciarrone2, Aljoscha Thomschewski2,3,4 and Nathalie Gerner2,3

1Faculty of Psychology, University of Akureyri, Iceland

2Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, Paracelsus Medical University, Austria

3Department of Mathematics, Paris-Lodron University of Salzburg, Austria

4Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University Salzburg, Austria


Klinefelter syndrome (KS) is one of the most common sex chromosome abnormalities and several cases are documented where children with KS present with epilepsy. Also, cognitive function deficits are common, despite high-functioning cases might occur. However, most reported cases are children or young adults.

We report a case of a 56-year-old patient with KS who presented in our clinic with potentially epileptic events. We found left-lateralized temporal intermittent rhythmic delta in routine electroencephalogram (EEG), high-frequency oscillations (HFOs, > 80 Hz) in high-density EEG (HD-EEG) that where pronounced over the left hemisphere, as well as left-temporal and paraventricular structural changes. Despite the patient was cognitively high functioning with excellent verbal and episodic memory performance, executive function tests involving inhibitory skills yielded significant differences against an age and sex-matched control group (N = 18).

This case suggests that high-functioning patients with KS may present with epilepsy-typical activity, that could be indicative for late-onset epilepsy. Diagnostic means of routine EEG can be complemented by HFO analysis of HD-EEG. Normal to high cognitive functioning may co-occur with deficits in single domains such as inhibition.