The End Of Knowledge - Vault 3 - G.TEC BCI & Neurotechnology Spring School 2024 - Day 10

graph LR classDef takeoka fill:#f9d4d4, font-weight:bold, font-size:14px; classDef mapping fill:#d4f9d4, font-weight:bold, font-size:14px; classDef stereoEEG fill:#d4d4f9, font-weight:bold, font-size:14px; classDef RTFM fill:#f9f9d4, font-weight:bold, font-size:14px; classDef challenges fill:#f9d4f9, font-weight:bold, font-size:14px; A[Masanori Takeoka] --> B[functional brain
mapping in pediatric epilepsy. 1] A --> C[Goal: maximize intervention,
minimize normal function impact. 2] A --> D[Localizing eloquent function
crucial for tailored surgery. 3] D --> E[Stereo EEG widely used
for invasive monitoring. 4] A --> F[Non-invasive mapping: fMRI,
TMS, MEG. 5] F --> G[Invasive mapping: cortical stimulation,
evoked potentials, high gamma. 5] A --> H[Real-time high gamma mapping
RTFM for stereo EEG. 6] H --> I[RTFM: passive, time-efficient,
OR/bedside, FDA-approved. 7] H --> J[RTFM induces fewer seizures,
usable in low-threshold regions. 8] H --> K[RTFM: longer paradigms, real-time
results, beyond epilepsy. 9] A --> L[Stereo EEG replacing subdurals,
especially in children. 10] L --> M[Placement hypothesis-based, tailored. 10] L --> N[Paradigms adjusted for
cooperation, cognitive level. 11] A --> O[46 pediatric cases over
5.5 years at BCH. 12] A --> P[Motor/sensory mapping avoids
disabling deficits. 13] P --> Q[Face/hand representation greater than leg. 13] P --> R[RTFM concordant with cortical
stimulation for motor/sensory. 14] A --> S[Language paradigms challenging
due to age, development. 15] S --> T[15 patients, left frontal/temporal
electrodes, expressive/receptive mapping. 16] S --> U[RTFM valuable for receptive
language, limited cooperation. 17] S --> V[RTFM requires more cooperation
for expressive vs receptive. 18] A --> W[Visual mapping with RTFM
identifies broad networks. 19] A --> X[Cortical stimulation established but
limited. RTFM complementary. 20] X --> Y[RTFM limited by placement
but samples deeper regions. 21] X --> Z[RTFM avoids seizures, stimulus
spread, allows multi-site testing. 22] A --> AA[RTFM enables studying inaccessible
language/cognition regions. 23] AA --> AB[RTFM complements cortical stimulation,
especially in children. 23] A --> AC[Unexpected RTFM findings suggest
broader networks. 24] AC --> AD[Verify patient isn't accidentally
activating other functions. 24] A --> AE[RTFM: motor/language networks more
extensive than cortical stimulation. 25] AE --> AF[Insular involvement needs further study. 25] A --> AG[Ideal receptive language paradigm:
multiple difficulties, non-linguistic sound. 26] A --> AH[Epilepsy often not curable,
but well-controlled if not genetic. 27] A --> AI[Youngest mapped: 3-4 years
stereo EEG, 1 year subdural. 28] A --> AJ[Stereo EEG wounds heal
well vs subdural grids. 29] A --> AK[Summary: RTFM and cortical
stimulation complementary for mapping. 30] class A,B takeoka; class C,P,Q,R,S,T,U,V,W,AA,AB,AC,AD,AE,AF,AG mapping; class D,E,L,M,N,AI,AJ stereoEEG; class F,G,H,I,J,K,X,Y,Z RTFM; class O,AH,AK challenges;

Resume:

1.- Dr. Masanori Takeoka discussed functional brain mapping with stereo EEG in pediatric epilepsy surgery at Boston Children's Hospital.

2.- The goal is to maximize intervention while considering effects on normal brain function. Surgical resection risks permanent deficits.

3.- Localizing eloquent function is crucial in tailoring epilepsy surgery. Stereo EEG has become widely used for invasive monitoring.

4.- Functional mapping techniques previously optimized for subdural electrodes are being expanded for stereo EEG.

5.- Non-invasive mapping includes fMRI, TMS, MEG. Invasive mapping uses cortical stimulation, evoked potentials, high gamma mapping.

6.- Real-time high gamma mapping (RTFM) has been developed for subdural electrodes and expanded to stereo EEG in children.

7.- RTFM is passive, time-efficient, used in the OR and bedside, and FDA-approved. It preserves seizure capture.

8.- RTFM is less likely to induce seizures than cortical stimulation and can be used in low-threshold regions.

9.- RTFM allows longer, more complex paradigms, real-time results and troubleshooting. It's valuable beyond just epilepsy cases.

10.- Stereo EEG is replacing subdurals, especially in children. Placement is hypothesis-based and tailored to each case.

11.- Paradigms are adjusted for cooperation and cognitive level. Electrode maps and paradigms are optimized to reduce artifacts.

12.- Data was presented from 46 pediatric cases over 5.5 years at Boston Children's Hospital with medically intractable epilepsy.

13.- Motor and sensory mapping localizes function to avoid disabling deficits. Face/hand representation is greater than leg.

14.- RTFM results generally concordant with cortical stimulation for motor/sensory mapping. Some abnormal co-activation patterns seen.

15.- Preparing language paradigms is challenging due to variability in age, development, cognition. Paradigms are tailored to each child.

16.- 15 patients with left frontal/temporal electrodes underwent expressive/receptive language mapping. RTFM helped differentiate response types.

17.- RTFM is valuable for receptive language mapping, especially in children with limited cooperation for cortical stimulation testing.

18.- RTFM requires more cooperation for expressive vs receptive language. It can confirm bilateral language seen on fMRI.

19.- Visual mapping with RTFM identifies broad networks beyond primary visual cortex that could be affected by resection.

20.- Cortical stimulation is established but has limitations (time, seizure risk, pair-wise testing). RTFM offers complementary advantages.

21.- RTFM is limited by electrode placement but can sample deeper regions and allow longer, more flexible paradigms.

22.- RTFM is unlikely to trigger seizures and can avoid stimulus spread issues. It allows simultaneous multi-site testing.

23.- RTFM enables studying previously inaccessible regions relevant to language/cognition. It complements cortical stimulation, especially in children.

24.- Unexpected findings with RTFM suggest broader networks. Verifying the patient isn't accidentally activating other functions is important.

25.- RTFM suggests motor/language networks may be more extensive than expected from cortical stimulation. Insular involvement needs further study.

26.- An ideal receptive language paradigm could include multiple difficulty levels and non-linguistic sound for subtraction.

27.- Epilepsy is often not completely curable, but can be well-controlled, especially if the cause is not genetic.

28.- The youngest patients mapped were 3-4 years old with stereo EEG, around 1 year old with subdural grids.

29.- Stereo EEG wounds heal well compared to subdural grids. Holes are not noticeable once healed.

30.- In summary, RTFM and cortical stimulation offer complementary tools for functional mapping in pediatric epilepsy. A combined approach is valuable.

Knowledge Vault built byDavid Vivancos 2024