The authors have no acknowledgements or financial disclosures.

Ensure that each patient is reviewed for suitability for the research study, and appropriate patients must be consented for participation in the study according to local IRB procedures.
1. Patient Selection for SEEG and Research
<ol>
	<li>Patient Selection for SEEG 
	Note: Epilepsy patients must be clinically assessed by a multidisciplinary team consisting of epileptologists, neuropsychologists and neurosurgeons.
	<ol>
		<li>Ensure that the patient has medically refractory focal epileps...

The authors have no conflict of interest to disclose.

In this paper SEEG was used to investigate the activity of local neuronal populations within the dACC during a decision-making task in humans. Previous work has investigated the activity of individual neurons in the dACC using intraoperative microelectode recordings 14 and demonstrated that dACC activity is modulated by previous activity. Microelectrode studies enable the investigation of the spiking activity of individual neurons. SEEG measures LFPs, which are related to the summated synaptic potentials acros...

Epilepsy, a common neurological disorder characterized by multiple recurrent seizures over time, accounts for 1% of the worldwide burden of diseases 1. Anti-epileptic medications fail to control seizures in 20 - 30% of patients 2,3. In these medically intractable patients, epilepsy surgery is often indicated 4,5. The decision to proceed with surgery requires locating the seizure focus, a prerequisite to formulating a surgical plan. Initially, non-invasive techniques are used to lateralize and localize the seizure focus. Electroencephalography (EEG), for example, measures cortical electrical activity recorded from electrodes placed on the scalp and can often provide sufficient information about the location of the seizure focus. In addition, magnetic resonance imaging (MRI) can demonstrate discrete lesions, such as hippocampal sclerosis, the classic pathology seen in the most common form of medically intractable epilepsy, mesial temporal lobe epilepsy (MTLE).
Frequently, however, the noninvasive workup is unable to identify a seizure focus. In these cases, invasive electrocorticography (ECoG) with intracerebral electrodes is required to localize the focus and guide further surgical treatment 6. ECoG is a neurophysiological technique used to measure electrical activity using electrodes placed in direct contact with the brain. Grids or strips of surface (subdural) electrodes are placed over the surface of the brain, a process that requires a craniotomy (removal of a bone flap) and large opening of the dura. These surface electrodes can be placed over the putative area(s) of seizure onset. The distal ends of the electrodes are tunneled through small openings in the skin and connected to the recording equipment in the epilepsy monitoring unit (EMU). In the EMU, the patient is monitored for clinical seizure activity through continuous video and ECoG recordings. This technique is useful for collecting long-term (days to weeks) recordings of ictal and interictal electrical discharges over relatively large areas of the cortical surface. While these intracranial recordings are invaluable clinically for investigating seizure foci and propagation, they also provide us with the opportunity to investigate cognitive function and neurophysiology in humans undergoing specifically designed behavioral tasks.
ECoG using subdural grid electrodes has been used to investigate various aspects of cortical function, including sensory and language processing. As one of many examples, Bouchard et al demonstrated the temporal coordination of the oral musculature in the formation of syllables for spoken language in the ventral sensorimotor cortex, a region identified as the human speech sensorimotor cortex 7. Furthermore, ECoG with subdural grid placement has also been utilized to study the mechanisms by which humans are able to attend to a particular voice within a crowd: the so-called &#8216;cocktail party effect&#8217; 8,9. ECoG recordings demonstrated that there are two distinct neuronal bands that dynamically track speech streams, both low frequency phase and high-gamma amplitude fluctuations, and that there are distinct processing sites - one &#8216;modulation&#8217; site that tracks both speakers, and one &#8216;selection&#8217; site that tracks the attended talker 5.
Another emerging application of ECoG with subdural electrode placement is the potential for use with Brain Computer Interfaces (BCIs), which &#8220;decode&#8221; neuronal activity in order to drive an external output. This technology has the potential of allowing patients with severe brain or spinal cord injuries to communicate with the world and manipulate prostheses 10,11.
While subdural grid placement has contributed greatly to our understanding of superficial cortical areas and is useful in identifying cortical epileptogenic foci, this technique does require a craniotomy and its attendant risks, and is generally limited to studying the outer surface of the brain. Stereotactic electroencephalography (SEEG) is a technique that enables the assessment of deep epileptogenic foci12. With a long history of use in France and Italy, it is also increasingly being used in the US 13. SEEG involves the placement of multiple electrodes (typically 10 - 16) deep within the substance of the brain through small (few mm) twist drill burr holes. Advantages of SEEG over subdural grid placement include its less invasive nature, the ease of examining bilateral hemispheres when required, and the ability to generate three-dimensional maps of seizure propagation. Furthermore, these electrodes enable the identification of deep epileptogenic foci that were previously difficult to identify with surface electrodes. This procedure also provides the opportunity to investigate the neurophysiology and function of deep cortical structures, such as the limbic system, the mesoparietal cortex, the mesotemporal cortex, and the orbitofrontal cortex, all of which were previously difficult to directly investigate in humans.
This paper demonstrates how SEEG can be utilized to investigate cognitive function in the dorsal anterior cingulate cortex (dACC). The dACC is a widely investigated brain region, but it is also one of the most poorly understood. Considered a significant region for human cognition, it is likely that the dACC is central to the dynamic neural processing of decisions in the context of continuously changing demands imposed by the environment 14. Studies in both primates 15,16 and humans 17 suggest that the dACC integrates potential risks and rewards of a given action, especially in situations of multiple simultaneous conflicting demands18-21, and modulates these decisions in the context of previous actions and their outcomes 14,22,23.
The Multi-Source Interference Task (MSIT), a Stroop-like behavioral task, is frequently used to investigate conflict processing in the dACC. The MSIT task activates the dACC by recruiting neurons involved in multiple domains of processing regulated by the dACC 24,25. This task specifically activates the dACC by testing features of decision-making, target detection, novelty detection, error detection, response selection, and stimulus/response competition. In addition, the MSIT task introduces multiple dimensions of cognitive interference, which are utilized in this study to investigate dACC neural responses to simultaneous conflicting stimuli using SEEG.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Trigger I/O cable</td>
			<td>Natus Medical Inc.</td>
			<td>5029</td>
			<td>PS2 to BNC cable</td>
		</tr>
		<tr>
			<td>BNC cables for analog pulses</td>
			<td></td>
			<td></td>
			<td>Can be ordered from most electronics stores.</td>
		</tr>
		<tr>
			<td>Power strip with surge protection and battery backup</td>
			<td>Tripp Lite</td>
			<td>SMART500RT1U UPC</td>
			<td>Power source and backup</td>
		</tr>
		<tr>
			<td>National instruments multifunctional daq data acquisition box NI PCIe-6382 DAQ cards</td>
			<td>National Instruments</td>
			<td>PCIe-6382 w/ BNC 2090A</td>
			<td>PCI cards for behavioral control interface</td>
		</tr>
		<tr>
			<td>Custom made button box - human interface device</td>
			<td></td>
			<td></td>
			<td>Any human interface device with three buttons may be used. Alternatively, 3 keyboard buttons may be used.</td>
		</tr>
		<tr>
			<td>Xltek 128 channel clinical intracranial EEG monitoring system EMU128FS</td>
			<td>Natus Medical Inc.</td>
			<td>002047c</td>
			<td>Clinical recording system</td>
		</tr>
		<tr>
			<td>Subject monitor and associated cables for visual stimulus presentation</td>
			<td>Dell</td>
			<td>U2212HMc</td>
			<td>Most Monitors are adequate here.</td>
		</tr>
		<tr>
			<td>Personal comptuer running behavioral software with DAQ cards installed</td>
			<td>Superlogics</td>
			<td>SL-2U-PD-Q87SLQ-BA</td>
			<td>Computer for recording neural data</td>
		</tr>
		<tr>
			<td>Mains cable for monitor</td>
			<td></td>
			<td></td>
			<td>Usually comes with the monitor, can be purchased at any electronics store.</td>
		</tr>
		<tr>
			<td>Monkey Logic software which runs on Matlab 2010A</td>
			<td></td>
			<td></td>
			<td>Free from MonkeyLogic website</td>
		</tr>
		<tr>
			<td>MATLAB 2010a software with data acquisition toolbox</td>
			<td>Mathworks</td>
			<td></td>
			<td>Matlab software</td>
		</tr>
		<tr>
			<td>sEEG electrodes AD TECH or PMT</td>
			<td>AD TECH</td>
			<td>2102-##-101</td>
			<td>Platinum tip, diameter (0.89 mm, 1 mm, 1.1 mm), uninsulated length 2.3 mm; The ## in the catalog number indicates the number of contacts on the electrode (08, 10, 12, or 16)</td>
		</tr>
		<tr>
			<td>Cabrio connectors</td>
			<td>PMT</td>
			<td>2125-##-01</td>
			<td>The ## in the catalog number indicates the number of contacts on the electrode (08, 10, 12, or 16)</td>
		</tr>
		<tr>
			<td>Tucker Davis Technologies Amplifier</td>
			<td>Tucker Davs Technologies</td>
			<td>PZ5</td>
			<td>preamplifier for neural data</td>
		</tr>
		<tr>
			<td>Tucker Davis Technologies processor</td>
			<td>Tucker Davs Technologies</td>
			<td>RZ2</td>
			<td>Neural signal processor for neural data</td>
		</tr>
		<tr>
			<td>TuckerDavis Technologies data streamer</td>
			<td>Tucker Davs Technologies</td>
			<td>RS4</td>
			<td>Data streamer and storage</td>
		</tr>
		<tr>
			<td>Fiber optics cables to connect TDT systems</td>
			<td>Tucker Davs Technologies</td>
			<td>F05</td>
			<td>Fiber optic cables for connecting Tucker Davis Technologies&#39; prodcuts.</td>
		</tr>
		<tr>
			<td>ribbon cable and snap serial connector for digital markers</td>
			<td></td>
			<td></td>
			<td>Can be ordered from ost electronics stores.</td>
		</tr>
		<tr>
			<td>personal computer fro running TDT RPvdsEx and OpenEx software</td>
			<td>Superlogics</td>
			<td>SL-2U-PD-Q87SLQ-BA</td>
			<td>computer for behavioral control</td>
		</tr>
		<tr>
			<td>middle atlantics server cabinet with casters</td>
			<td>Middle Atlantic Products</td>
			<td>PTRK-21</td>
			<td>Server case to house all of the research items</td>
		</tr>
		<tr>
			<td>Tucker Davis Technologies splitter box to split clinical and research recrodings</td>
			<td>Tucker Davs Technologies</td>
			<td></td>
			<td>This splitter box is a semi-custom device. Researchers should consult the attending neurologists about splitting the research and clinical recordings in a way that doesn&#39;t interfere with clinical care.</td>
		</tr>
		<tr>
			<td>Researcher monitor with requisite cables</td>
			<td>Dell</td>
			<td>U2212HMc</td>
			<td>Most Monitors are adequate here.</td>
		</tr>
		<tr>
			<td>button box power source - 5 volts, 2 amperes</td>
			<td></td>
			<td></td>
			<td>Can be purchased at any electronics store.</td>
		</tr>
		<tr>
			<td>TDT optical interface PCI card</td>
			<td>Tucker Davs Technologies</td>
			<td>P05</td>
			<td></td>
		</tr>
	</tbody>
</table>

investigating the function of deep cortical and subcortical structures using stereotactic electroencephalography: lessons from the anterior cingulate cortex

Stereotactic Electroencephalography (SEEG) is a technique used to localize seizure foci in patients with medically intractable epilepsy. This procedure involves the chronic placement of multiple depth electrodes into regions of the brain typically inaccessible via subdural grid electrode placement. SEEG thus provides a unique opportunity to investigate brain function. In this paper we demonstrate how SEEG can be used to investigate the role of the dorsal anterior cingulate cortex (dACC) in cognitive control. We include a description of the SEEG procedure, demonstrating the surgical placement of the electrodes. We describe the components and process required to record local field potential (LFP) data from consenting subjects while they are engaged in a behavioral task. In the example provided, subjects play a cognitive interference task, and we demonstrate how signals are recorded and analyzed from electrodes in the dorsal anterior cingulate cortex, an area intimately involved in decision-making. We conclude with further suggestions of ways in which this method can be used for investigating human cognitive processes.

Once a patient is selected for SEEG electrode placement, he/she undergoes a volumetric T2 and T1 contrast enhanced MRI. SEEG electrode trajectories are then planned using stereotactic navigation of the volumetric MRI sequences (Figure 1). This technique allows for the collection of local field potentials from structures deep within the cortex such as dorsal anterior cingulate cortex (light orange trajectory, Figure 1) that would not be possible with typical surface electrode placement. P...

Watch this Scientific Journal Video about Investigating the Function of Deep Cortical and Subcortical Structures Using Stereotactic Electroencephalography: Lessons from the Anterior Cingulate Cortex a

Investigating the Function of Deep Cortical and Subcortical Structures Using Stereotactic Electroencephalography: Lessons from the Anterior Cingulate Cortex

Stereotactic Electroencephalography (SEEG) is an operative technique used in epilepsy surgery to help localize seizure foci. It also affords a unique opportunity to investigate brain function. Here we describe how SEEG can be used to investigate cognitive processes in human subjects.

Stereotactic Electroencephalography (SEEG) is a technique used to localize seizure foci in patients with medically intractable epilepsy. This procedure ...

investigating-function-deep-cortical-subcortical-structures-using

Research

JoVE Journal

Neuroscience

12.1K Görüntüleme.  Columbia University Medical Center, New York Presbyterian Hospital.  Stereotaktik Elektroensefalografi (SEEG) nöbet odakları yerelleştirilmesine yardımcı epilepsi cerrahisinde kullanılan bir cerrahi tekniktir. Aynı zamanda beyin fonksiyonu araştırmak için benzersiz bir fırsat tanıyor. Burada SEEG insan bireylerde kognitif işlemlerini incelemek için nasıl kullanılabileceğini açıklar. 

Video: Investigating the Function of Deep Cortical and Subcortical Structures Using Stereotactic Electroencephalography: Lessons from the Anterior Cingulate Cortex