Cortical activation during menopausal hot flashes.

OBJECTIVE

To determine regions of brain activation associated with menopausal hot flashes and sweating.

DESIGN

Controlled laboratory study.

SETTING

University medical center.

PATIENT(S): Symptomatic postmenopausal women and asymptomatic eumenorrheic women.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Brain activation measured by functional magnetic resonance imaging.

RESULT(S): Significant (P<.001) areas of activation during hot flashes in symptomatic women included the insula and anterior cingulate cortex. Sweating in the eumenorrheic women was associated (P<.001) with activity in the anterior cingulate and superior frontal gyrus.

CONCLUSION(S): Activation of the insular cortex is associated with the "rush of heat" described during menopausal hot flashes. Thermoregulation in humans appears to be represented in a distributed cortico-subcortical network rather than in a single localized structure.