PT  - JOURNAL ARTICLE
AU  - E.H. Middlebrooks
AU  - R.A. Popple
AU  - E. Greco
AU  - L. Okromelidze
AU  - H.C. Walker
AU  - D.A. Lakhani
AU  - A.R. Anderson
AU  - E.M. Thomas
AU  - H.D. Deshpande
AU  - B.A. McCullough
AU  - N.P. Stover
AU  - V.W. Sung
AU  - A.P. Nicholas
AU  - D.G. Standaert
AU  - T. Yacoubian
AU  - M.N. Dean
AU  - J.A. Roper
AU  - S.S. Grewal
AU  - M.T. Holland
AU  - J.N. Bentley
AU  - B.L. Guthrie
AU  - M. Bredel
TI  - Connectomic Basis for Tremor Control in Stereotactic Radiosurgical Thalamotomy
AID  - 10.3174/ajnr.A7778
DP  - 2023 Feb 01
TA  - American Journal of Neuroradiology
PG  - 157--164
VI  - 44
IP  - 2
4099  - http://www.ajnr.org/content/44/2/157.short
4100  - http://www.ajnr.org/content/44/2/157.full
SO  - Am. J. Neuroradiol.2023 Feb 01; 44
AB  - BACKGROUND AND PURPOSE: Given the increased use of stereotactic radiosurgical thalamotomy and other ablative therapies for tremor, new biomarkers are needed to improve outcomes. Using resting-state fMRI and MR tractography, we hypothesized that a “connectome fingerprint” can predict tremor outcomes and potentially serve as a targeting biomarker for stereotactic radiosurgical thalamotomy.MATERIALS AND METHODS: We evaluated 27 patients who underwent unilateral stereotactic radiosurgical thalamotomy for essential tremor or tremor-predominant Parkinson disease. Percentage postoperative improvement in the contralateral limb Fahn‐Tolosa‐Marin Clinical Tremor Rating Scale (TRS) was the primary end point. Connectome-style resting-state fMRI and MR tractography were performed before stereotactic radiosurgery. Using the final lesion volume as a seed, “connectivity fingerprints” representing ideal connectivity maps were generated as whole-brain R-maps using a voxelwise nonparametric Spearman correlation. A leave-one-out cross-validation was performed using the generated R-maps.RESULTS: The mean improvement in the contralateral tremor score was 55.1% (SD, 38.9%) at a mean follow-up of 10.0 (SD, 5.0) months. Structural connectivity correlated with contralateral TRS improvement (r = 0.52; P  = .006) and explained 27.0% of the variance in outcome. Functional connectivity correlated with contralateral TRS improvement (r = 0.50; P  = .008) and explained 25.0% of the variance in outcome. Nodes most correlated with tremor improvement corresponded to areas of known network dysfunction in tremor, including the cerebello-thalamo-cortical pathway and the primary and extrastriate visual cortices.CONCLUSIONS: Stereotactic radiosurgical targets with a distinct connectivity profile predict improvement in tremor after treatment. Such connectomic fingerprints show promise for developing patient-specific biomarkers to guide therapy with stereotactic radiosurgical thalamotomy.BOLDblood oxygen level–dependent MRIDBSdeep brain stimulationDRTTdentato-rubro-thalamic tractSMSsimultaneous multisliceSRSstereotactic radiosurgeryTRSFahn‐Tolosa‐Marin Clinical Tremor Rating ScaleVIMventral intermediate nucleus