Brain Tumors
Conditions
Keywords
Time to contact estimation, awake brain surgery, brain tumor, cerebral mapping
Brief summary
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.
Detailed description
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.
Interventions
BEHAVIORALBehavioral 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.
PROCEDUREAwake 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
The Mini Mental State Evaluation, which generally assesses the cognitive state of an individual through his 6 subtests testing both working memory, episodic and semantic praxies as well as spatio-temporal orientation capacity.
Sponsors
University Hospital, Toulouse
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Cerebral mapping | 61 months | Look at how the cognitive functions of perception of time before contact are attached to brain structures, their communication with other zones, their alteration due to brain tumors for patients with a brain tumor compared to control subjects. The treatment of the study being an awakened awakening as part of the routine care, there is no risk of serious adverse event. Brain mapping will be done through neurological examinations which are questionnaires and a risk-free task. All the tasks and all the questionnaires described in the paragraph arm and intervention will make it possible to meet this outcome. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Look the implication of other brain areas | 61 months | Look to see if brain areas other than those targeted for stimulation in awake surgery are stimulated and therefore play a role in estimating time to contact.The treatment of the study being an awakened awakening as part of the routine care, there is no risk of serious adverse event. Other brain areas will be define through neurological examinations which are questionnaires and a risk-free task. All the tasks and the questionnaires described in the paragraph arm and intervention will make it possible to meet this outcome. |
Countries
France
Contacts
Primary ContactFranck-Emmanuel ROUX, MD
Backup ContactRobin BAURES
Outcome results
None listed