Thalamic volumetric analysis in Developmental and/or Epileptic Encephalopathy with Spike Wave Activation in Sleep (D/EE-SWAS): A cross-sectional study

Abstract

Objectives

This cross-sectional study compared the thalamic volume (TV) of children with Developmental and/or Epileptic Encephalopathy with Spike-Wave Activation in Sleep (D/EE-SWAS) with age matched children with well-controlled epilepsy(WCE).

Methods

An unaided eye assessment of T1-weighted brain MRI sequences and quantitative volumetric analysis through “volBrain” online software was performed in children (5–12 years) with steroid-naïve D/EE-SWAS {spike-wave-index(SWI) in sleep≥50 %} and typically developing children with WCE (seizure-free period ≥1-year). The absolute and relative thalamic volume (ATV/RTV) (RTV: thalamic volume as percentage of the total intracranial volume), were compared between the two groups.

Results

Twenty-children each with D/EE-SWAS (14 boys; mean age: 8.05±1.76 years) and WCE (15 boys; mean age: 9.1 ± 1.74 years) were analysed. In the D/EE-SWAS group, (16/20) 80% of participants had a structural lesion while all the children in the WCE group had a presumed genetic etiology. Volumetric analysis detected low ATV (<2 standard deviation) in 12/20 (60 %) children with D/EE-SWAS while unaided eye assessment could pick up thalamic involvement only in six (30 %). On comparison with WCE group (N = 20), mean ATV and RTV in structural D/EE-SWAS (n = 16) [(7.25 cm³ ± 1.66 versus 11.17 cm³ ± 1.22; p < 0.0001)(0.73 % ± 0.17 versus 0.87 % ± 0.05; p < 0.001)] and presumed genetic D/EE-SWAS (n = 4) [(9.25 cm³ ± 0.55, versus 11.17 cm³ ± 1.22, p < 0.01)(0.74 % ± 0.04 versus 0.87 % ± 0.05; p < 0.0001)] were significantly reduced. ATV did not correlate with SWI in sleep EEG (r =-0.25) in D/EE-SWAS.

Conclusion

Thalamic volume is reduced in majority of children with D/EE-SWAS in both structural and presumed genetic etiology.