Mehrnaz Jenabi1, Kyung K Peck2, Robert J Young3, Nicole Brennan1, Andrei I Holodny4. 1. Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA. 2. Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA. 3. Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Department of Radiology, Weill Medical College of Cornell University, New York, 10065 NY, USA. 4. Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Department of Radiology, Weill Medical College of Cornell University, New York, 10065 NY, USA. Electronic address: holodnya@mskcc.org.
Abstract
BACKGROUND AND PURPOSE: Accurate localization of anatomically and functionally separate SMA tracts is important to improve planning prior to neurosurgery. Using fMRI and probabilistic DTI techniques, we assessed the connectivity between the frontal language area (Broca's area) and the rostral pre-SMA (language SMA) and caudal SMA proper (motor SMA). MATERIALS AND METHODS: Twenty brain tumor patients completed motor and language fMRI paradigms and DTI. Peaks of functional activity in the language SMA, motor SMA and Broca's area were used to define seed regions for probabilistic tractography. RESULTS: fMRI and probabilistic tractography identified separate and unique pathways connecting the SMA to Broca's area - the language SMA pathway and the motor SMA pathway. For all subjects, the language SMA pathway had a larger number of voxels (P<0.0001) and higher connectivity (P<0.0001) to Broca's area than did the motor SMA pathway. In each patient, the number of voxels was greater in the language and motor SMA pathways than in background pathways (P<0.0001). No differences were found between patients with ipsilateral and those with contralateral tumors for either the language SMA pathway (degree of connectivity: P<0.36; number of voxels: 0.35) or the motor SMA pathway (degree of connectivity, P<0.28; number of voxels, P<0.74). CONCLUSION: Probabilistic tractography can identify unique white matter tracts that connect language SMA and motor SMA to Broca's area. The language SMA is more significantly connected to Broca's area than is the motor subdivision of the SMA proper.
BACKGROUND AND PURPOSE: Accurate localization of anatomically and functionally separate SMA tracts is important to improve planning prior to neurosurgery. Using fMRI and probabilistic DTI techniques, we assessed the connectivity between the frontal language area (Broca's area) and the rostral pre-SMA (language SMA) and caudal SMA proper (motor SMA). MATERIALS AND METHODS: Twenty brain tumorpatients completed motor and language fMRI paradigms and DTI. Peaks of functional activity in the language SMA, motor SMA and Broca's area were used to define seed regions for probabilistic tractography. RESULTS: fMRI and probabilistic tractography identified separate and unique pathways connecting the SMA to Broca's area - the language SMA pathway and the motor SMA pathway. For all subjects, the language SMA pathway had a larger number of voxels (P<0.0001) and higher connectivity (P<0.0001) to Broca's area than did the motor SMA pathway. In each patient, the number of voxels was greater in the language and motor SMA pathways than in background pathways (P<0.0001). No differences were found between patients with ipsilateral and those with contralateral tumors for either the language SMA pathway (degree of connectivity: P<0.36; number of voxels: 0.35) or the motor SMA pathway (degree of connectivity, P<0.28; number of voxels, P<0.74). CONCLUSION: Probabilistic tractography can identify unique white matter tracts that connect language SMA and motor SMA to Broca's area. The language SMA is more significantly connected to Broca's area than is the motor subdivision of the SMA proper.
Authors: Luca Pasquini; Alberto Di Napoli; Maria Camilla Rossi-Espagnet; Emiliano Visconti; Antonio Napolitano; Andrea Romano; Alessandro Bozzao; Kyung K Peck; Andrei I Holodny Journal: Front Hum Neurosci Date: 2022-02-18 Impact factor: 3.169