Functional magnetic resonance imaging of activation in subcortical auditory pathway.
OBJECTIVE
Functional magnetic resonance imaging (fMRI) has been used to investigate activation of the auditory cortex; however, assessment of activation in the subcortical auditory pathway has been challenging. The aim of this study was to examine neural correlates of cortical and subcortical auditory activation evoked by pure-tone stimulus using silent fMRI.


METHODS
Prospective analysis.


METHODS
Seventeen normal-hearing volunteers (7 male, 10 female; age range, 14-37 yrs) underwent silent fMRI. An audiometer was used to deliver pure tones of 1000 Hz to the left ear. Pure tones were presented at hearing thresholds determined in the scanner. Brain regions showing increased activation during pure-tone stimulus presentation were mapped and auditory activations exceeding P <.001 were included in the analysis.


RESULTS
Pure-tone stimuli evoked bilateral activation in cortical regions of the transverse and superior temporal gyri and the planum temporale. Activation in subcortical structures included the medial geniculate body, inferior colliculus, lateral lemniscus, superior olivary complex, and cochlear nucleus.


CONCLUSIONS
Silent functional magnetic resonance imaging findings documented the feasibility of detecting activation elicited by pure tone along the cortical and subcortical auditory pathway. The use of this technique in the assessment of disorders with auditory dysfunction merits further investigation.
Yetkin
F Zerrin
FZ
Department of Radiology, University of Texas Southwestern Medical Center at Dallas, 75390-8896, USA. zerrin.yetkin@UTSouthwestern.edu
Roland
Peter S
PS
Mendelsohn
Dianne B
DB
Purdy
Phillip D
PD
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001300:Audiometry, Evoked Response; D001301:Audiometry, Pure-Tone; D001303:Auditory Cortex / Q000033:anatomy & histology / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies