Brain Areas of Time-To-Contact Perception: an Awake Surgery Study

Study Purpose

During a brain surgery targeted to remove a brain tumor, the neurosurgeon wakes up the patient to delimit the tumor area exactly, and identify the surrounding areas, to limit the surgery damages. The present project aims at testing the patient in this awake phase to determine the brain areas implied in time to contact (TTC) perception, a function that allows determining the arrival time of moving objects and used in many tasks of our daily life.

Recruitment Criteria

Accepts Healthy Volunteers Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms	Yes
Study Type An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes. An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes. Searching Both is inclusive of interventional and observational studies.	Interventional
Eligible Ages	18 Years - 70 Years
Gender	All

More Inclusion & Exclusion Criteria

Inclusion Criteria:

For the patients:

- Brain tumor that does not affect the dominant hand motricity.

The patient that have a tumor in an area targeted for a cortical stimulation will be automatically enrolled within the Pre-End group.

- Who will agree with all terms and sign the experimental agreement.

- Correct or corrected vision, as allowed by the surgery constraints.

- With no known oculomotor abnormalities (list of exclusion in Annexe) - Affiliated to a social security system.

For the control group:

- Who will agree with all terms and sign the experimental agreement.

- Correct or corrected vision.

- With no known oculomotor abnormalities.

- Affiliated to a social security system.

Exclusion Criteria:

For the patients:

- Brain tumor located in the occipital area.

- Legally protected patient, or with unknown ability to sign the experimental agreement, as determined by the medical team.

- Medical background of neurological diseases of the central nervous system, as Parkinson, Alzheimer, stroke.

- Pregnancy.

For the control group:

- Legally protected patient, or with unknown ability to sign the experimental agreement, as determined by the medical team.

- Medical background of neurological diseases of the central nervous system, as Parkinson, Alzheimer, stroke.

- Pregnancy

Trial Details

Trial ID: This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.	NCT04128306
Phase Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans. Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data. Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs. Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.	N/A
Lead Sponsor The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.	University Hospital, Toulouse
Principal Investigator The person who is responsible for the scientific and technical direction of the entire clinical study.	Franck-Emmanuel Roux, MD
Principal Investigator Affiliation	University Hopsital Toulouse
Agency Class Category of organization(s) involved as sponsor (and collaborator) supporting the trial.	Other
Overall Status	Recruiting
Countries	France
Conditions The disease, disorder, syndrome, illness, or injury that is being studied.	Brain Tumors

Additional Details

Time to contact (TTC) estimation is a major visual function that allows an observer determining the time a moving object will take to reach him. It is however striking to note that the different brain areas supporting this function are not clearly identified, in particular the contribution of non-visual areas that are engaged in the definition of a peri-personal space for the observer. This lack could be fulfilled during a brain surgery experiment. Indeed, in such a surgery, the patient is awakened, and the surgeon apply direct cortical stimulation to de-activate specific brain areas while testing different cognitive function. The failure to succeed in the task indicates that this area is engaged in the cognitive function. The present study therefore will test different brain areas to investigate their respective contribution in the TTC estimation function. Three groups of participants will be tested, in pre and per surgery phases. After an initial pre-surgery phase, patients for which the tumor does not interfere with the TTC estimation anility will be enrolled in the Pré-Per group, and tested during the brain surgery. Patients for which the pre-test indicates that the TTC estimation is damaged by the tumor, will be tested in pre-surgery phase only, constituting the Pré-End group. Finally, a control group, paired with the patients, will be tested as well. For the patients, all the testing phases will be achieved during their medical process. The awake surgery is now a well-established technique, currently and usually done at the University Hospital Toulouse, and the present test in the per surgery phase only lasts a couple of minutes, no more than 5 minutes. As such, there is no additional risk carried out in the project.

Arms & Interventions

Arms

Experimental: Patient group

A total of 120 patients with brain tumors will be divided into our two groups, divided as follows: In the group Pre-Per, 20 patients will be included by localization of electrical stimulation (60 patients in total). A patient who would be stimulable in two different areas could be included in two different groups. In the group Pre-End, the subjects will be distributed by localization of the brain tumor, by lobe. A total of 20 participants will be included per lobe, corresponding to the frontal, temporal or parietal lobes (as a reminder, a tumor in the occipital lobe is an exclusion criterion), for a total of 60 participants

Active Comparator: Control group

A maximum of 120 healthy matched sex and age subjects with patients will also be included

Interventions

Behavioral: - Behavioral task

In the task, participants will see an object approaching toward them. During its movement, the object disappears, and the participants have to press a button to indicate when they estimate the object to contact with them. The motion parameters of the ball will be varied. The pre and post-surgery phases will test the participants in a long duration version of the task, approximately 30 minutes. The per surgery phase will be made of a 5 minutes version of the task, and the participants will receive a direct cortical stimulation for 4 seconds, at an intensity of 1 to 10 milliampere (mA), in the premotor ventral area, or posterior parietal cortex or somesthetic associative areas.

Procedure: - Awake surgery

The patient is first anesthetized for opening the scalp and skull, then awake. During this waking phase, the surgeon passes a few quick and simple tests to the patient, visual (for example, line bisection), language (for example, repeating a list of words) etc. While doing this task, the neurosurgeon disrupts the functioning of certain brain regions by direct electrical stimulation of the cortex in order to identify the regions whose dysfunction will have an impact on the current task. During the operation, the areas involved in the construction of the peri-personal space will be stimulated by direct electrical stimulation, for a duration of 4 seconds at an intensity of 1 to 10 mA. These areas are: Ventral premotor cortex (with the exception of the primary motor cortex controlling the dominant hand, so as not to interfere with the motor response of the patient) Posterior parietal cortex Associative somesthetic areas