Abstract Details

Title Effect of Steroids on cortical excitability in children with Encephalopathy with Status Epilepticus in Sleep (ESES): A TMS based longitudinal study

Topic Epilepsy/Clinical Neurophysiology (EEG)

Presentation(s) S13 - Epilepsy/Clinical Neurophysiology (EEG): Antiseizure Medications (1:24 PM-1:36 PM)

Poster/Presentation
Number 003

Background State of cortical excitedness in refractory pediatric epilepsies such as ESES is not known. Clinical response to steroids in ESES is well accepted, however its impact on real-time cortical excitability has never been studied.

Objective We analyzed the change in cortical excitability of the motor cortex of the dominant hemisphere, in children with Encephalopathy with Status Epilepticus in Sleep (ESES), pre- and post-steroid therapy, using single and paired-pulse Transcranial Magnetic Stimulation (TMS) parameters (RMT – Resting Motor Threshold; LICI – Long-Interval Cortical Inhibition; SICI – Short-Interval Cortical Inhibition).

Design/Methods Children (5-12 years) with immunotherapy naïve ESES (spike-wave index (SWI) in sleep ≥50%) were enrolled. RMT, LICI (100-msec inter-stimulus interval (ISI)) and SICI (3-msec ISI) were measured (in %), at baseline, 4-weeks, and 12-weeks post-steroid therapy. All received five-day intravenous methylprednisolone followed by oral steroids 2 mg/kg for 6-weeks and tapering over next 6-weeks. TMS parameters were correlated with electroclinical outcome [EEG (SWI), SQ (VSMS), behaviour profile (CBCL)]. In addition, baseline TMS parameters in ESES were compared with healthy controls.

Results Twenty children with ESES (14 boys; mean age: 8.05+1.76 years) were enrolled. All of them had neurobehavioral symptoms and cognitive decline at the time of presentation. 60% had active seizures. Motor cortex was significantly inhibited in ESES compared to healthy controls (N=20). {RMT [86.3+6.96 vs 58.05+4.71 (p< 0.0001)]; LICI [55.05+4.39 vs 73.9+3.75 (p< 0.0001)]; SICI [39.2+4.36 vs 55.45+4.78 (p< 0.0001)]} Post steroid therapy, motor cortex inhibition got significantly reduced both at 4 and 12 weeks of therapy as compared to baseline {(RMT: 71.45+9.83, 63.45+8.48); (LICI: 66.00+6.26, 74.50+5.36); (SICI: 49.35+6.24, 56.05+5.57)} [p<0.0001] TMS parameters correlated with sleep-EEG SWI, at all time-points [RMT (r +0.7); LICI (r -0.7); SICI (r -0.7)].

Conclusions Motor cortex is significantly inhibited in ESES. TMS parameters of cortical excitability correlate with SWI. Effective steroid therapy elevates motor cortex inhibition.

Authors/Disclosures
Gautam Kamila (ALL INDIA INSTITUTE OF MEDICAL SCIENCES, NEW DELHI) PRESENTER	Mr. Kamila has nothing to disclose.
	No disclosure on file
Sheffali Gulati, MD, FAMS, FIAP, FIMS (All India Institute of Medical Sciences)	Prof. Gulati has nothing to disclose.
	No disclosure on file
	No disclosure on file
	No disclosure on file
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	No disclosure on file