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Grey matter density in the right caudate nucleus predicts aphasic patients’ response to speech comprehension therapy

Victoria Fleming1, 2*, Sonia Brownsett1, 3 and Alex P. Leff1, 2
  • 1 University College London, Brain Repair and Rehabilitation, Institute of Neurology, United Kingdom
  • 2 University College London, Institute of Cognitive Neuroscience, United Kingdom
  • 3 Queensland University of Technology, Department of Psychology, Australia

Introduction: Patients with aphasia (PWA) present with heterogeneous profiles of language functioning. Impairment based therapies can significantly improve language outcomes, but there is considerable variability in treatment response (Brady, Kelly, Godwin, Enderby, & Campbell, 2016). Imaging methods have provided insights into the relationship between brain structure and cognitive and language functioning in PWA (Leff et al., 2009; Stebbins et al., 2008). However, less is known about how these factors influence response to therapy, and imaging studies addressing this question are rare (Aguilar et al., 2018 in press). Here we used voxel-based morphometry (VBM) to investigate the relationship between grey matter tissue density from a pre-therapy magnetic resonance imaging (MRI) scan, and response to speech comprehension therapy, in a group of PWA. Method: Twenty-five PWA with speech comprehension impairments, caused by left hemisphere stroke, completed a 12-week block of speech comprehension therapy (‘Listen-In’). ‘Listen-In’ consists of an automated program of spoken word and sentence-to-picture matching tasks targeting comprehension of single words, presented on a computer tablet. Improvements were assessed using a bespoke measure of single word auditory comprehension pre and post therapy, calculated as a simple raw percentage change. T1 structural MRI scans were obtained at baseline. Results: VBM analysis identified a single grey matter cluster in the right dorsal striatum, at the head of the caudate nucleus with some overlap with the globus pallidum. This cluster significantly co-varied with PWA response to therapy (family-wise error corrected PFWE=0.04, kE=465, co-ordinates of peak 12 12 0). The relationship was positive i.e. greater grey matter density (at pre-therapy) was associated with larger improvements in spoken word comprehension following therapy. Discussion: The caudate nucleus is part of a complex network of cortico-basal-ganglia-thalamic loops, which interconnect with distributed cortical networks (Draganski et al., 2008). Our cluster, in the head of the caudate, shows the largest connectivity overlap with the dorsolateral prefrontal cortex (DLPFC), and smaller overlap with the medial prefrontal and orbitofrontal cortex (Draganski et al., 2008). This part of the caudate has a key role in goal planning, underlying many cognitive tasks (Grahn, Parkinson, & Owen, 2008), while the main cortical area it is connected to, DLPFC, is involved in domain-general executive functions, including cognitive control (Barber & Carter, 2005). PWA have been found to engage cognitive control networks during listening tasks, and this may be one mechanism whereby PWA instantiate therapeutic gains; healthy controls show equivalent activation, but only during effortful listening (Brownsett et al., 2014). Our result is compatible with this account. Differences in right caudate grey matter density, that partially explain who responded best to Listen-In therapy, were from pre-therapy MRI scans. These could be part and parcel of pre-existing individual differences, or could be a more plastic response to their aphasic stroke. Longitudinal studies are required to distinguish between these, and other possibilities. Summary: We show that grey matter density in the head of the right caudate, part of a complex network of cortico-striatal connections associated with cognitive control, predicts response to speech comprehension therapy in a group of PWA.

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References

Aguilar, O., Kerry, S. J., Ong, Y.-H., Callaghan, M., Crinion, J., Woodhead, Z., . . . Hope, T. (2018 in press). Lesion site dependent treatment responses to therapy after aphasic stroke. Journal of Neurology, Neurosurgery & Psychiatry.

Barber, A. D., & Carter, C. S. (2005). Cognitive Control Involved in Overcoming Prepotent Response Tendencies and Switching Between Tasks. Cerebral Cortex, 15(7), 899-912. doi: 10.1093/cercor/bhh189

Brady, M. C., Kelly, H., Godwin, J., Enderby, P., & Campbell, P. (2016). Speech and language therapy for aphasia following stroke. The Cochrane database of systematic reviews(6). doi: 10.1002/14651858.CD000425.pub4

Brownsett, S., Warren, J. E., Geranmayeh, F., Woodhead, Z., Leech, R., & Wise, R. J. S. (2014). Cognitive control and its impact on recovery from aphasic stroke. Brain, 137(1), 242-254. doi: 10.1093/brain/awt289

Draganski, B., Kherif, F., Klöppel, S., Cook, P. A., Alexander, D. C., Parker, G. J. M., . . . Frackowiak, R. S. J. (2008). Evidence for Segregated and Integrative Connectivity Patterns in the Human Basal Ganglia. The Journal of Neuroscience, 28(28), 7143-7152. doi: 10.1523/JNEUROSCI.1486-08.2008

Grahn, J. A., Parkinson, J. A., & Owen, A. M. (2008). The cognitive functions of the caudate nucleus. Progress in neurobiology, 86(3), 141-155. doi: 10.1016/j.pneurobio.2008.09.004

Leff, A. P., Schofield, T. M., Crinion, J. T., Seghier, M. L., Grogan, A., Green, D. W., & Price, C. J. (2009). The left superior temporal gyrus is a shared substrate for auditory short-term memory and speech comprehension: evidence from 210 patients with stroke. Brain, 132(12), 3401-3410. doi: 10.1093/brain/awp273

Stebbins, G. T., Nyenhuis, D. L., Wang, C., Cox, J. L., Freels, S., Bangen, K., . . . Gorelick, P. B. (2008). Gray Matter Atrophy in Patients With Ischemic Stroke With Cognitive Impairment. Stroke, 39(3), 785-793. doi: 10.1161/STROKEAHA.107.507392

Keywords: Aphasia, Caudate Nucleus, Speech and language therapy, post stroke aphasia, chronic aphasia, Basal Ganglia, Striatum, dorsal striatum, cognitive control, DOMAIN GENERAL PROCESSING, Computerised therapy, Voxel Based Morphometry (VBM), MRI imaging

Conference: Academy of Aphasia 56th Annual Meeting, Montreal, Canada, 21 Oct - 23 Oct, 2018.

Presentation Type: oral presentation

Topic: not eligible for a student prize

Citation: Fleming V, Brownsett S and Leff AP (2019). Grey matter density in the right caudate nucleus predicts aphasic patients’ response to speech comprehension therapy. Conference Abstract: Academy of Aphasia 56th Annual Meeting. doi: 10.3389/conf.fnhum.2018.228.00032

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Received: 30 Apr 2018; Published Online: 22 Jan 2019.

* Correspondence: Ms. Victoria Fleming, University College London, Brain Repair and Rehabilitation, Institute of Neurology, London, United Kingdom, victoria.fleming@ucl.ac.uk