Pediatric SEEG: An Overview
ACNS Annual Course, Feb 10, 2021
Ahsan Moosa Naduvil Valappil, MD Pediatric Epileptologist, Epilepsy Center, Cleveland Clinic @AMoosaMD Outline
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Are children SEEG in When is small adults? children SEEG not Outcome. needed? Are Children small adults? 1 For the most part, answer is YES in SEEG What’s the Youngest Age for SEEG?
Bone density/ thickness is the main criterion . Thin bone – securing the guiding bolt/ electrodes; bone effraction by stereotactic pinholder Usually around 18 mos- 2 yrs; after 2 years generally safe
Guenot et al, Clin Neuroph 2018; Cossu et al, CNS 2006 “Anatomo-Electro-Clinical” in SEEG
Anatomo Electro Clinical
• Region • Type and • Clinical where propagation signs/ electrodes of Ictal symptoms are SEEG of seizures patterns
Correlation in Time and Space of clinical semiology
Chassoux et al, 2018 Clin Neurophys, Isnard et al 2018, Clin Neurophy, Gonzalez & Najm 2014, CNS “Anatomo-Electro-Clinical” Pre-Implantation
Anatomo Electro Clinical
• Where to • Interictal & • Clinical place Ictal EEG signs/ electrodes? patterns symptoms of seizures “Anatomo” – Lesion on MRI
Anatomo Electro Clinical
• MRI • EEG- • Semiology Interictal • Deficits PET • EEG-Ictal SPECT ‘MEG’
A relevant lesion on MRI is the surrogate for SEEG in many cases Potential Scenarios Needing Invasive Monitoring
• Non-lesional focal epilepsy • “Lesional” but discordant (lesion may be incidental) • Multiple lesions with electro-clinical data not clearly suggesting concordance • Bilateral exploration • Proximity to eloquent cortex, especially when anatomy is distorted
Modified from: Gonzalez & Najm 2014, CNS Semiological Signs In Adults* Localizing & Lateralizing ‘Localizing’ /non-lateralizing
Automotor with Version Todd’s palsy preserved Hypermotor awareness
Unilateral Clonic Unilateral Eye- Auditory aura Automotor sensory aura blinking
Tonic/ tonic - Post-ictal Nose- Olfactory aura Gelastic clonic Visual aura) wiping
Figure –of-4 sign Ictal Aphasia Emesis Bilateral tingling Pain
Unilateral Chapeau-de- Ictal Speech Ictal Spitting Drooling Dystonic gendarme
* Only selected signs In young children Interpreting indirect signs of subjective sensations in young children
An illustrative case Left arm jerks in a 2 year old- Is there any aura before that? 2 year old with left arm jerks
• Onset 21 months • Left arm jerks; drops objects, quick jerks, at times in cluster • 2-3 clusters a day • Rarely left whole body clonic seizure • Exam normal; MRI normal
Looking at his arms about 5-10 sec before the jerks, suggested a sensory component Sharp Waves: Right Centro-Parietal N
M Resection in post H central gyrus
S
P
X
Y Seizure Free 3 years… Z Case Example P4/O2 SW 13 Y M
Fearful Breaths heavy SEEG PLAN MEG Shuffles in bed Hold railings Right Parietal Agitated Gets out of bed Stiffening, L> Rt SEEG in Children: Outcome & Complications 2 Localization & Resection
• Epileptogenic Zone Identification - 89% to 95% (McGovern et al 2019; Ho et al 2018) • SEEG leading to resection - 70 to 78% (McGovern et al 2019; Taussig et al 2014; Abel et al 2018) Pediatric SEEG series Lesion Mean folloup Outcome Comments on MRI Cossu 2005 35 cases; 80% 32 mo 60% SZ free Lesionectomy 2; lesionectomy plus 26; ‘cortical’ resection 7 Cossu M 15 cases 87% 1 year 60% Engel 1 1 died (4 not operated) 2012 Dormfuller 19 cases 84% 29 months 85% FCD only 2012 Gonzalez 30 cases 40% 26 months 60% (of 18) 12 had no resection 2014 Taussig 65 cases 80% 24 months 67% Engel 1 2014 Abel 17 cases 53% 12 months 33% (of 12) Robotic assisted 2018 McGovern 57 cases 44% 19 months 50% (of 42) 1/3 rd-unilobar 2019 2/3 rd multi SEEG in 57 Children
McGovern RA et al. J Neurosurg Pediatr 2019 Invasive EEG in <3 years
• Taussig et al, 2012 • 26 children, < 3 years • All had lesions • 20 had SDE with depths; 6 had SEEG (all older than 2 years) • To define boundaries was the rationale for invasive monitoring • 9 /26 cases: EZ wider than the lesion!
Taussig et al, 2012, Seizure SEEG in TSC
• Neal et al; 18 pts, 11 children, 13 adequate sampling • 2 patterns: (i) Focal dominant tuber pattern -7 (ii) Complex pattern (surrounding cortex plus) -6 • 80% Engel IA with distinct dominant tuber characteristics - Continuous interictal discharges (IEDs; 100%) - FLAIR hypointense center (86%), - Center-to-rim Epileptogenicity index gradient, and - Stimulation-induced seizures (71%).
Neal et al, 2019, Epilepsia Complication Rate
SEEG Subdural Grid
ICH 1% ICH 4%
Infection Infection 0.8% 2.3%
Mullin J 2016, Epilepsia 6 deaths reported overall; one child Hemorrhage rate “0.2% per electrode” Gonzalez-Martinez, 2014, 2016 When is SEEG Unhelpful in Children? 3 West Syndrome & Epileptogenic Lesion
Interictal Epileptogenic Lesion Guides Surgery
Ictal Epileptic Encephalopathy
Hypsarrhythmia Epileptic Spasms Focal brain lesions With Abundant Slow Spike Wave Complexes Generalized Tonic, tonic clonic, drop Discharges on EEG
ESES/ CSWS Epileptic Encephalopathy
Hypsarrhythmia Epileptic Spasms Focal brain lesions With Abundant Slow Spike Wave Complexes Generalized Tonic, tonic clonic, drop Discharges on EEG
CSWS
Why does this occur in Children? What Determines Semiology?
+ + Avoid SEEG … • Less than 2 years of age - Most surgical candidates are lesional • Epileptic encephalopathies with abundant generalized discharges - If non-lesional, unlikely to be ‘solved’ by SEEG - Lesional, SEEG not needed • Bilateral studies without acquiring all potentially useful non-invasive studies Key Takeaways
• General approach to implantation for SEEG in children are similar to adults. - Non-availability of certain localizing signs/ symptoms limits - Safe to do in children aged 2 years or older • Seizure freedom rates range from 50-70% in most series. • Avoid SEEG in children with poorly localizing features & abundant generalized discharges. My Learning Curve
Fellowship Fellowship Staff Staff Staff Year 1 Year 2 Year 1 Year 2 Year 7
Modified from: http://sascha-kasper.com/the-bumpy-learning-curve/ Thank you