The object of this study was to define caudate nucleus locations responsive to intraoperative direct electrical stimulation for tinnitus loudness modulation and relate those locations to functional connectivity maps between caudate nucleus subdivisions and auditory cortex.
Six awake study participants who underwent bilateral deep brain stimulation (DBS) electrode placement in the caudate nucleus as part of a phase I clinical trial were analyzed for tinnitus modulation in response to acute stimulation at 20 locations. Resting-state 3-T functional MRI (fMRI) was used to compare connectivity strength between centroids of tinnitus loudness-reducing or loudness-nonreducing caudate locations and the auditory cortex in the 6 DBS phase I trial participants and 14 other neuroimaging participants with a Tinnitus Functional Index > 50.
Acute tinnitus loudness reduction was observed at 5 caudate locations, 4 positioned at the body and 1 at the head of the caudate nucleus in normalized Montreal Neurological Institute space. The remaining 15 electrical stimulation interrogations of the caudate head failed to reduce tinnitus loudness. Compared to the caudate head, the body subdivision had stronger functional connectivity to the auditory cortex on fMRI (p < 0.05).
Acute tinnitus loudness reduction was more readily achieved by electrical stimulation of the caudate nucleus body. Compared to the caudate head, the caudate body has stronger functional connectivity to the auditory cortex. These first-in-human findings provide insight into the functional anatomy of caudate nucleus subdivisions and may inform future target selection in a basal ganglia–centric neuromodulation approach to treat medically refractory tinnitus.
Correspondence Steven W. Cheung: University of California, San Francisco, CA. firstname.lastname@example.org.INCLUDE WHEN CITING Published online February 8, 2019; DOI: 10.3171/2018.10.JNS181659.Disclosures Ms. Heath has been a consultant for Medtronic, and she and Dr. Larson have received honoraria from Medtronic.
GillesAVan HalGDe RidderDWoutersKVan de HeyningP: Epidemiology of noise-induced tinnitus and the attitudes and beliefs towards noise and hearing protection in adolescents. PLoS One8:e702972013
GillesA, Van HalG, De RidderD, WoutersK, Van de HeyningP: Epidemiology of noise-induced tinnitus and the attitudes and beliefs towards noise and hearing protection in adolescents. 8:e70297, 2013)| false
JungWHJangJHParkJWKimEGooEHImOS: Unravelling the intrinsic functional organization of the human striatum: a parcellation and connectivity study based on resting-state FMRI. PLoS One9:e1067682014
JungWH, JangJH, ParkJW, KimE, GooEH, ImOS, : Unravelling the intrinsic functional organization of the human striatum: a parcellation and connectivity study based on resting-state FMRI. 9:e106768, 2014)| false