Functional Organization of Somatosensory Responses in the Secondary Somatosensitive Area and Insula

Centre Hospitalier Universitaire de Saint Etienne25 enrolled

Overview

The implication of the second somatosensory area (SII) and the insular cortex in the processing of somatosensory inputs is now well established. However the functional anatomy of these areas hidden in the depth of the sylvian scissure remain mostly unknown. The aim of this fMRI study is to determine the functional cartography of SII and insula. The localization of responses to different somatosensory stimuli (slight touch, warm, cold, heat pain and arthrokinesia) applied on the left hand of 25 healthy volunteers, will be compared.

Aims : Demonstrate that localization of the several types of somatosensory stimuli is different into SII and into insula. If possible, we'll determine a functional cartography of these areas.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Healthy

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * 25 healthy volunteers will be included ranging in age from 18 to 50 years * contraception needed for women * right handed * All the subjects have to give their written informed consent. Exclusion Criteria: * pregnancy * neurological or psychiatric disease * drugs taken \<12h before fMRI * contra-indications to fMRI : pacemaker, clip, metallic device * Refusing to be informed of the presence of a cerebral abnormality, detected during MRI.

Outcomes

Primary Outcomes

Comparison of euclidian distances between the centroids of clusters activations for the different types of stimulations into SII and insula.

Time frame: one day

Secondary Outcomes

Determine the Talairach coordinates of the centroids of clusters of activations for the different types of somatosensory stimuli into SII and insula