Epilepsy
Conditions
Brief summary
The purpose of this study is to test microelectrodes in intracranial monitoring to see if they will provide novel information on the epileptic potential of the implanted brain tissue. A secondary objective is to investigate the activity of single neurons during specific cognitive tasks.
Detailed description
The standard-of-care for medically refractory epilepsy is resective brain surgery. In certain patients, precise localization of the epileptic focus is done using intracranial EEG (iEEG) recording. In this type of EEG recording, electrodes are placed on the brain surface or inserted into the brain through an opening in the skull. In addition to standard electrode recording, this study will use ultra thin microelectrodes. Microelectrodes are only several micrometers thick and are useful because they are able to record the activity of single neurons in isolation. Such recordings have tremendous clinical potential in epilepsy surgery and tremendous research potential in cognitive neuroscience.
Interventions
DEVICEMicroelectrodes
Microelectrode implantation
Sponsors
National Institute of Neurological Disorders and Stroke (NINDS)
Dartmouth-Hitchcock Medical Center
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* 18-65 year old * male or female * right or left handed * IQ\>70 * medically refractory focal epilepsy requiring intracranial EEG for pre-surgical evaluation deemed medically necessary * no contraindications to intracranial electrode study * able and willing to participate in research
Exclusion criteria
* does not meet the inclusion criteria
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Feasibility of Microelectrode Technology to Isolate Place Responsive Neurons in the Human Hippocampus as Measured by the Number of Place Responsive Neurons. | Evaluated for each patient during monitoring period of approximately 2 weeks | With the occipito-temporal implantation approach of implantation of microelectrodes, feasibility will measured by the number of place responsive neurons that could be isolated. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage). | Evaluated for each patient during monitoring period of approximately 2 weeks | Secondary objective is to investigate whether it is possible to predict the speed of which each participant is performing and navigating during the cognitive task via the intracranial spectral EEG changes (alpha, beta, delta, theta, gamma, and high-gamma) during these tasks. Accuracy of frequency band (brain waves) predicting speed during specific cognitive tasks is measured by how precisely the frequency band predicts navigational speed and is expressed as a percentage of correct prediction. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Microelectrodes Patients who qualify for this study will be implanted with standard electrodes as well as microelectrodes for their intracranial seizure monitoring.
Microelectrodes: Microelectrode implantation | 34 |
| Total | 34 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | These patients were not implanted with intracranial electrodes for clinical reasons . | 4 |
Baseline characteristics
| Characteristic | Microelectrodes |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 34 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants |
| Race (NIH/OMB) White | 33 Participants |
| Sex: Female, Male Female | 17 Participants |
| Sex: Female, Male Male | 17 Participants |
| Sex/Gender, Customized | 34 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 30 |
| other Total, other adverse events | 0 / 30 |
| serious Total, serious adverse events | 2 / 30 |
Outcome results
Primary
Feasibility of Microelectrode Technology to Isolate Place Responsive Neurons in the Human Hippocampus as Measured by the Number of Place Responsive Neurons.
With the occipito-temporal implantation approach of implantation of microelectrodes, feasibility will measured by the number of place responsive neurons that could be isolated.
Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks
Population: Participants included patients undergoing intra-cranial EEG monitoring for TLE and are implanted with depth electrodes and microelectrodes via the trans-occipital approach. The total number of place responsive neurons recorded from all participants is reported below.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Microelectrodes | Feasibility of Microelectrode Technology to Isolate Place Responsive Neurons in the Human Hippocampus as Measured by the Number of Place Responsive Neurons. | 79 place responsive neurons |
Secondary
How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage).
Secondary objective is to investigate whether it is possible to predict the speed of which each participant is performing and navigating during the cognitive task via the intracranial spectral EEG changes (alpha, beta, delta, theta, gamma, and high-gamma) during these tasks. Accuracy of frequency band (brain waves) predicting speed during specific cognitive tasks is measured by how precisely the frequency band predicts navigational speed and is expressed as a percentage of correct prediction.
Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks
Population: Participants included patients undergoing intra-cranial EEG monitoring for TLE and are implanted with depth electrodes and microelectrodes.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Microelectrodes | How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage). | Delta | 0.477 percentage of accuracy in decimals |
| Microelectrodes | How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage). | Theta | 0.490 percentage of accuracy in decimals |
| Microelectrodes | How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage). | Alpha | 0.440 percentage of accuracy in decimals |
| Microelectrodes | How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage). | Beta | 0.444 percentage of accuracy in decimals |
| Microelectrodes | How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage). | Gamma | 0.362 percentage of accuracy in decimals |
| Microelectrodes | How Precise the Frequencies (Alpha, Beta, Delta, Theta, Gamma, and High-gamma) of Neural Brain Activity Predict the Speed of the Participant at Performing the Cognitive Task (Accuracy Measured in Percentage). | High-gamma | 0.382 percentage of accuracy in decimals |