Fronto-thalamic networks and the left ventral thalamic nuclei play a key role in aphasia after thalamic stroke

• Published in: Communications biology 2024-06, Vol.7 (1), p.700-13
• Main Authors: Rangus, Ida, Rios, Ana Sofia, Horn, Andreas, Fritsch, Merve, Khalil, Ahmed, Villringer, Kersten, Udke, Birgit, Ihrke, Manuela, Grittner, Ulrike, Galinovic, Ivana, Al-Fatly, Bassam, Endres, Matthias, Kufner, Anna, Nolte, Christian H.
• Format: Article
• Language: English
• Subjects: 59; 59/57; 631/378/2649/1594; 631/378/3920; 692/617/375/534; Adult; Aged; Aphasia; Aphasia - diagnostic imaging; Aphasia - etiology; Aphasia - physiopathology; Biomedical and Life Sciences; Connectome; Female; Frontal Lobe - diagnostic imaging; Frontal Lobe - physiopathology; Functional magnetic resonance imaging; Globus pallidus; Hemispheric laterality; Humans; Lesions; Life Sciences; Magnetic Resonance Imaging; Male; Mapping; Middle Aged; Nerve Net - diagnostic imaging; Nerve Net - physiopathology; Neural Pathways - physiopathology; Stroke - complications; Stroke - physiopathology; Thalamic nuclei; Thalamus; Thalamus - diagnostic imaging; Thalamus - physiopathology; Ventral Thalamic Nuclei - diagnostic imaging; Ventral Thalamic Nuclei - physiopathology
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-024-06399-9

Thalamic aphasia results from focal thalamic lesions that cause dysfunction of remote but functionally connected cortical areas due to language network perturbation. However, specific local and network-level neural substrates of thalamic aphasia remain incompletely understood. Using lesion symptom mapping, we demonstrate that lesions in the left ventrolateral and ventral anterior thalamic nucleus are most strongly associated with aphasia in general and with impaired semantic and phonemic fluency and complex comprehension in particular. Lesion network mapping (using a normative connectome based on fMRI data from 1000 healthy individuals) reveals a Thalamic aphasia network encompassing widespread left-hemispheric cerebral connections, with Broca’s area showing the strongest associations, followed by the superior and middle frontal gyri, precentral and paracingulate gyri, and globus pallidus. Our results imply the critical involvement of the left ventrolateral and left ventral anterior thalamic nuclei in engaging left frontal cortical areas, especially Broca’s area, during language processing. A lesion symptom mapping and lesion network mapping study suggests that lesions in the left ventral thalamic nuclei, linked to thalamic aphasia, map onto a common left-hemispheric network, with Broca’s area showing the strongest associations.