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#Schalk "Gerwin Schalk, Ph.D."

Gerwin Schalk, Ph.D.

Wadsworth Center, NY

Deputy Director, National Center for Adaptive Neurotechnologies

Real-time functional brain mapping (RTFM) with cortiQ is not only critical for clinical evaluations prior to invasive brain surgery, it is also an invaluable tool for scientific research that is based on electrocorticographic (ECoG) signals. Because the time that is available with ECoG subjects is very limited, it is important to optimize experimental testing to the specific electrode coverage of the subject. We use cortiQ to rapidly determine the functional significance of the covered electrode locations. For example, the cortiQ mapping result shown in Fig. 1 illustrates the location of hand motor and visual cortices. Based on this output, we conducted a study using a visuo-motor task, which produced spectacular results (Fig. 2) that have recently been published1. Thus, cortiQ-based mapping has allowed us to be much more efficient in our ECoG-based research.

1. W. G. Coon, A. Gunduz, P. Brunner, A. L. Ritaccio, B. Pesaran, G. Schalk: “Oscillatory phase modulates the timing of neuronal activations and resulting behavior“, NeuroImage 133 (2016) 294{301}.

 

Figure 1

Figure 1: Real-time functional mapping (RTFM) with cortiQ rapidly reveals which brain areas are covered by electrode implants. ECoG grids are shown as translucent overlays above a reconstructed cortical model. Small black dots on each grid or strip represent electrode locations, and red circles with orange borders indicate regions reactive to a visuomotor task (in this case, manipulating a Rubik’s cube). Blue and yellow circles indicate reference and ground electrodes, respectively. Note the clear activations over sensorimotor cortex, and also visual areas near the occipital pole. This map was constructed from less than 3 minutes of real-time data recording.

 

Figure 2

Figure 2: With functional coverage over visual and motor regions verified using RTFM, we could derive exemplary spatiotemporal trajectories of task-related neuronal population activity in single trials. A) Task-related cortical locations from one subject, and the time course of neuronal population activity in exemplary locations (right). Increases in activity at each location are brief. B) Population-level activity reflected in ECoG signals occurs during the trough of alpha oscillations (8–12 Hz).

#Kamada "Kyousuke Kamada, MD, Ph.D"

Kyousuke Kamada, MD, Ph.D.

Asahikawa Medical University

In my work, I often have to identify specific brain areas as part of routine neurosurgical procedure. cortiQ enables us to make real-time functional maps not only of motor, but also of language-related functions at the bed side or in operating rooms. In our experience, cortiQ has demonstrated a high sensitivity and specificity (between 80% and 90%), which is sufficient for use in clinical practice2. In addition, real-time cortiQ mapping has allowed us to completely avoid the risk of seizure caused by electrocortical stimulation (ECS) and helped us to understand functional dynamics as well. Real-time visualization of high gamma activity using cortiQ has great potential for less-invasive brain mapping techniques in basic and clinical neuroscience.

The images in Figure 3 show how different areas of a patient’s brain became active during specific tasks, while the patient underwent surgical treatment for a brain tumor. As the patient performs tasks, such as picture naming or reading, cortiQ detects the precise brain areas responsible. This makes it much easier to conduct surgery effectively. Additionally, in the presented case here we found a cortical region that was mainly related to the recognition process of Kanji characters, which could be confirmed by both cortiQ (Figure 3) and ECS (Figure 4). cortiQ is a great product that makes brain mapping much faster, safer, and more informative.

2. Ogawa, H. et al., “Rapid and Minimum Invasive Functional Brain Mapping by Real-Time Visualization of High Gamma Activity During Awake Craniotomy.” World Neurosurg. 82, 912.e1–912.e10 (2014).

 

Figure 3

Figure 3: cortiQ mapping results of three language related tasks. The red circles with the yellow border indicate significant high-gamma activation (p < 0.05) after Bonferroni correction. The tasks “Listen”, “Name the picture” and “Read the Kanji” took 15, 20 and 26 seconds, respectively, and were repeated three times.

 

Figure 4

Figure 4: ECS mapping results for language related functional regions on the cortex are represented by colored circles. The resected tumor is highlighted by the rounded rectangle.

Expressive Language Impaired

Receptive Language Impaired

Dyslexia of Kanji “strawberry”

Tumor

 

#Korostenskaja "Milena Korostenskaja, Ph.D."

Milena Korostenskaja, Ph.D.

University of Florida

cortiQ is electrocorticography-based real-time functional mapping technique that has strong potential to become alternative to current golden standard of functional mapping–electrical cortical stimulation (ESM). There are numerous advantages of cortiQ when compared to ESM, such as flexible stimulus presentation, time- and effort- effectiveness, possibility to work with patients that are unable actively engage in the task. In addition, cortiQ is less invasive than ESM and can be effectively used in pediatric population, which other functional mapping methodologies do not always allow.