Authors :
Presenting Author: Hiroya Ono, MD,PhD – UCLA Mattel Children's Hospital
Atsuro Daida, MD,PhD – UCLA Mattel Children's Hospital
Saarang Panchavati, BS – UCLA
Sotaro Kanai, MD,PhD – UCLA Mattel Children's Hospital
Yipeng Zhang, Dr. – UCLA
Raman Sankar, MD,PhD – UCLA Mattel Children's Hospital
Noriko Salamon, MD,PhD – UCLA Mattel Children's Hospital
Aria Fallah, MD, MS – UCLA Mattel Children's Hospital
Vwani Roychowdhury, PhD – UCLA
William Speier, PhD – UCLA
Hiroki Nariai, MD, PhD, MS – UCLA Mattel Children's Hospital
Rationale:
The involvement of the thalamocortical network in language function has been suggested, but its detailed dynamics during auditory naming tasks have not yet been explored. This study examined the thalamocortical network dynamics using intracranial electroencephalograms (iEEG) to leverage their high temporal resolution.
Methods:
We studied five patients (ages 10–28) with drug-resistant epilepsy who underwent chronic iEEG monitoring with thalamic sampling to determine their candidacy for thalamic neuromodulation. The patients performed auditory naming tasks, responding aloud to sentence-based questions. Time-frequency analysis was used to determine the spatiotemporal dynamics of high-gamma (70–110 Hz) and delta activity (1–4 Hz) at the onset of auditory stimuli and responses. Coherence analysis was conducted to assess connectivity between cortical regions and thalamic nuclei, including the anterior nucleus (AN) and centromedian nucleus (CM).
Results: At the auditory stimulus onset, high-gamma augmentation was observed in the bilateral superior temporal gyri, the left supramarginal gyrus, and the right transverse temporal gyrus, with no changes in the right supramarginal gyrus or the thalamus. Changes in delta activity paralleled those of high-gamma activity in the cortical areas (Figure 1). Delta activity in the left CM showed an early increase (peaking at 200 msec), followed by the left AN (peaking at 1300 msec). The left CM showed a more pronounced delta augmentation compared to the right. Coherence analysis revealed a strong delta connection between the left superior temporal gyrus and the ipsilateral AN (Figure 2). At the response onset, high-gamma augmentation was observed in the bilateral precentral gyri, along with delta augmentation in the left precentral region. Coherence analysis revealed positive delta correlations between the left/right precentral gyrus and the ipsilateral AN.
Conclusions:
We demonstrated the temporal activation of thalamocortical networks during auditory naming tasks, modulated through delta frequency. Our results suggest that the dynamic activation of thalamocortical networks plays a crucial role in language processing.
Funding: National Institute of Neurological Disorders and Stroke (NINDS) K23NS128318, Uehara Memorial Foundation, and SENSHIN Medical Research Foundation