Knowledge Vault 3/93 - G.TEC BCI & Neurotechnology Spring School 2024 - Day 10
cortiQ 2.0: Running functional mapping procedures in
real-time with high-gamma and ultra-high gamma
Christoph Kapeller, g.tec medical engineering GmbH (AT)
<Resume Image >

Concept Graph & Resume using Claude 3 Opus | Chat GPT4 | Llama 3:

graph LR classDef surgery fill:#f9d4d4, font-weight:bold, font-size:14px; classDef ECoG fill:#d4f9d4, font-weight:bold, font-size:14px; classDef highGamma fill:#d4d4f9, font-weight:bold, font-size:14px; classDef cortiQ fill:#f9f9d4, font-weight:bold, font-size:14px; classDef applications fill:#f9d4f9, font-weight:bold, font-size:14px; Main[Christoph Kapeller] --> A[Functional brain mapping preserves
tissue during surgery 1] Main --> B[Brain mapping methods: ECoG,
fMRI, PET, ECS, TMS, Wada 2] Main --> C[High gamma ECoG shows
focal, task-related power increases 3] C --> D[Activation co-localizes with
low frequency suppression 4] C --> E[High gamma predicts deficits,
resection decreases language scores 5] C --> F[ECoG + ECS mapping
improves glioma patient survival 6] Main --> G[CortiQ: automated, real-time,
intuitive ECoG mapping system 7] G --> H[CortiQ uses common average
reference, 70-170 Hz band 8] G --> I[CortiQ use cases:
awake and two-stage surgery 9] G --> J[CortiQ montage creator aligns
cortex photo with electrodes 10] G --> K[CortiQ paradigm editor creates
tasks with stimuli and blocks 11] G --> L[CortiQ mapping detects activations
in real-time over baseline 12] Main --> M[Awake CortiQ mapping detects
anatomy-matched activations faster than ECS 13] Main --> N[CortiQ corresponds well to
ECS, improves seizures and survival 14] Main --> O[CortiQ co-localizes with fMRI,
ECS for language 15] Main --> P[CortiQ SEEG maps grasping,
visual and language dynamics 16] Main --> Q[CortiQ guides ECS, high
gamma peak indicates stimulation effect 17] Q --> R[Ultra high gamma 300-800 Hz
best matches ECS symptoms 18] Main --> S[High sampling rate enables
ultra high gamma recording 19] Main --> T[CortiQ identifies Broca's area,
some temporal dynamics between spots 20] Main --> U[Electrode localization uses MRI/CT
in GTEC software for CortiQ 21] Main --> V[CortiQ is certified amplifier/software
system using g.HIamp 22] Main --> W[CortiQ central sulcus polarity
inversion is somatosensory evoked potential 23] Main --> X[ECoG electrodes can terminate
seizures with closed-loop stimulation 24] Main --> Y[Face activation is bilateral,
word form left, face regions right 25] class A,M,N surgery class B,C,D,E,F,O,P,Q,R,S,X ECoG class R,S highGamma class G,H,I,J,K,L,T,U,V,W cortiQ class Y applications


1.- Functional brain mapping during surgery preserves functional tissue in areas like motor, language, and visual cortex.

2.- Methods include high gamma electrocorticography (ECoG), fMRI, PET, electrical cortical stimulation (ECS), transcranial magnetic stimulation, and Wada test.

3.- High gamma (70-170 Hz) ECoG shows task-related power increases over 500%, localizing activation. Low frequencies like mu are more widespread.

4.- Activation co-localizes with low frequency suppression but is more focal. Random firing lifts broadband high gamma, indicating neural activity.

5.- Research shows high gamma predicts 28% of deficits alone. Resecting high gamma language areas decreases language scores.

6.- Glioma patients had longer survival when adding ECoG to ECS mapping. High gamma found critical areas ECS missed.

7.- Automated, real-time, intuitive ECoG mapping system developed (CortiQ) as alternative to complex fMRI. CE and FDA cleared.

8.- CortiQ uses common average reference, 200ms time windows, 70-170 Hz band. R^2 activation metric displayed on brain map.

9.- Two use cases: 1) Awake surgery with ECoG then ECS. 2) Two-stage with electrodes implanted first, then ECoG and resection.

10.- Montage creator aligns exposed cortex photo with electrodes. Grid/strip database has common models. SEEG aligned to CT/MRI.

11.- Paradigm editor creates picture naming or other tasks with 3s stimuli, 21s blocks, 4 tasks max. Visuals instruct patient.

12.- Mapping excludes bad channels, common average reference, starts task. Activations appear in real-time over baseline.

13.- Awake mapping detects tongue, auditory, hand activations matching anatomy in 9 min. ECS took 26 min. Passive listening activates language.

14.- Awake and anesthetized mapping corresponded well to ECS. CortiQ plus ECS reduced intraoperative seizures and increased glioma survival.

15.- CortiQ co-localized with fMRI language in 5/5 patients, ECS in 2/5. Mapped expressive and receptive language with SEEG.

16.- CortiQ SEEG maps grasping 400-500ms post-cue. Visual and expressive language activity follows picture naming dynamics.

17.- CortiQ results guide ECS. Stimulating at high gamma peak causes transient aphasia. Effect more likely before peak.

18.- ECS symptoms best match ultra high gamma (300-800 Hz), even better than 70-170 Hz. Suggests optimal stimulation timing.

19.- High sampling rate and downsampling enables ultra high gamma recording with low noise. Next step: integrated CortiQ stimulator.

20.- Red expressive language bubbles likely Broca's area not motor cortex based on anatomy. Some temporal dynamics between spots.

21.- Intracranial electrode localization uses MRI/CT coregistration in GTEC intracranial montage creator software, compatible with CortiQ.

22.- CortiQ is a certified integrated amplifier/software system using g.HIamp, not standalone software, to ensure quality.

23.- CortiQ central sulcus polarity inversion is somatosensory evoked potential, different from high gamma activation.

24.- ECoG electrodes can terminate seizures with closed-loop stimulation, similar to NeuroPace RNS, using grids or SEEG.

25.- Face activation is bilateral but right lateralized. Word form is left dominant. Specific face regions mostly right, some bilateral.

Knowledge Vault built byDavid Vivancos 2024