Abstract
Introduction
It is often clinically difficult to assess the severity of aphasia in the earliest stage of cerebral infarction. A method enabling objective assessment of verbal function is needed for this purpose. We examined whether diffusion tensor (DT) tractography is of clinical value in assessing aphasia.
Methods
Thirteen right-handed patients with left middle cerebral artery infarcts who were scanned within 2 days after stroke onset were enrolled in this study. Magnetic resonance data of ten control subjects were also examined by DT tractography. Based on the severity of aphasia at discharge, patients were divided into two groups: six patients in the aphasic group and seven in the nonaphasic group. Fractional anisotropy (FA) and number of arcuate fasciculus fibers were evaluated. Asymmetry index was calculated for both FA and number of fibers.
Results
FA values for the arcuate fasciculus fibers did not differ between hemispheres in either the patient groups or the controls. Number of arcuate fasciculus fibers exhibited a significant leftward asymmetry in the controls and the nonaphasic group but not in the aphasic group. Asymmetry index of number of fibers was significantly lower (rightward) in the aphasic group than in the nonaphasic (P = 0.015) and control (P = 0.005) groups. Loss of leftward asymmetry in number of AF fibers predicted aphasia at discharge with a sensitivity of 0.83 and specificity of 0.86.
Conclusions
Asymmetry of arcuate fasciculus fibers by DT tractography may deserve to be assessed in acute infarction for predicting the fate of vascular aphasia.
Similar content being viewed by others
References
Muir KW, Buchan A, von Kummer R, Rother J, Baron JC (2006) Imaging of acute stroke. Lancet Neurol 5:755–768
Buchel C, Readler T, Sommer M, Sach M, Weiller C, Koch MA (2004) White matter asymmetry in the human brain: a diffusion tensor MRI study. Cerebral Cortex 14:945–951
Catani M, Jones DK, Ffyrche DH (2005) Perisylvian language networks of the human brain. Ann Neurol 57:8–16
Nucifora PGP, Verma R, Melhem ER, Gur RE, Gur RC (2005) Leftward asymmetry in relative fiber density of the arcuate fasciculus. Neuroreport 8:791–794
Parker GJ, Luzzi S, Alexander DC, Wheeler-Kingshott CA, Ciccarelli O, Lambon Ralph MA (2005) Lateralization of ventral and dorsal auditory-language pathways in the human brain. Neuroimage 24:656–666
Powell HW, Parker GJ, Alexander DC, Symms MR, Boulby PA, Wheeler-Kingshott CA, Barker GJ, Noppeney U, Koepp MJ, Duncan JS (2006) Hemispheric asymmetries in language-related pathways: a combined functional MRI and tractography study. Neuroimage 32:388–399
Vernooij MW, Smits M, Wielopolski PA, Houston GC, Krestin GP, van der Lugt A (2007) Fiber density asymmetry of the arcuate fasciculus in relation to functional hemispheric language lateralization in both right-and left-handed healthy subjects: a combined fMRI and DTI study. Neuroimage 35:10640–10760
Hickok G, Poeppel D (2004) Dorsal and ventral streams: a framework for understanding aspects of the functional anatomy of language. Cognition 92:67–99
Engelter ST, Gostynski M, Papa S, Frei M, Born C, Ajdacic-Gross V, Gutzwiller F, Lyrer PA (2006) Epidemiology of aphasia attributable to first ischemic stroke: incidence, severity, fluency, etiology, and thrombolysis. Stroke 37:1379–1384
Wade DT, Hewer RL, David RM, Enderby PM (1986) Aphasia after stroke: natural history and associated deficits. J Neurol Neurosurg Psychiatry 49:11–16
Pedersen PM, Vinter K, Olsen TS (2004) Aphasia after stroke: type, severity and prognosis. The Copenhagen Aphasia Study. Cerebrovasc Dis 17:35–43
Yamada K, Nagakane Y, Mizuno T, Hosomi A, Nakagawa M, Nishimura T (2007) MR tractography depicting damage to the arcuate fasciculus in a patient with conduction aphasia. Neurology 68:789
Lyden P, Brott T, Tilley B, Welch KM, Mascha EJ, Levine S, Haley EC, Grotta J, Marler J (1994) Improved reliability of the NIH Stroke Scale using video training. NINDS TPA Stroke Study Group. Stroke 25:2220–2226
Barber PA, Demchuk AM, Zhang J, Buchan AM (2000) Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score. Lancet 355:1670–1674
Pierpaoli C, Basser PJ (1996) Toward a quantitative assessment of diffusion anisotropy. Magn Reson Med 36:893–906
Godefroy O, Dubois C, Debachy B, Leclerc M, Kreisler A (2002) Lille Stroke Program. Vascular aphasias: main characteristics of patients hospitalized in acute stroke units. Stroke 33:702–705
Hillis AE, Gold L, Kannan V, Cloutman L, Kleinman JT, Newhart M, Heidler-Gary J, Davis C, Aldrich E, Llinas R, Gottesman RF (2008) Site of the ischemic penumbra as a predictor of potential for recovery of functions. Neurology 71:184–189
Kreisler A, Godefroy O, Dalmaire C, Debachy B, Leclercq M, Pruvo JP, Leys D (2000) The anatomy of aphasia revisited. Neurology 54:1117–1123
Croquelois A, Wintermark M, Reichhart M, Meuli R, Bogousslavsky J (2003) Aphasia in hyperacute stroke: language follows brain penumbra dynamics. Ann Neurol 54:321–329
Catani M, Mesulam M (2008) The arcuate fasciculus and the disconnection theme in language and aphasia: history and current state. Cortex 44:953–961
Makris N, Kennedy DN, McInerney S, Sorensen AG, Wang R, Caviness VS Jr, Pandya DN (2005) Segmentation of subcomponents within the superior longitudinal fascicle in humans; a quantitative, in vivo, DT-MRI study. Cerebral Cortex 15:854–869
Bhagat YA, Emery DJ, Shuaib A, Sher F, Rizvi NH, Akhatar N, Clare TL, Leatherdale T, Beaulieu C (2006) The relationship between diffusion anisotropy and time of onset after stroke. J Cereb Blood Flow Metab 26:1442–1450
Acknowledgments and funding
None
Conflict of interest statement
We declare that we have no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hosomi, A., Nagakane, Y., Yamada, K. et al. Assessment of arcuate fasciculus with diffusion-tensor tractography may predict the prognosis of aphasia in patients with left middle cerebral artery infarcts. Neuroradiology 51, 549–555 (2009). https://doi.org/10.1007/s00234-009-0534-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00234-009-0534-7