Prediction of Aphasia Outcome Using Diffusion Tensor Tractography in Patients with Acute Ischemic Stroke

Abstract

troke is a leading cause of major adult disability, and aphasia is one of the most common consequences of stroke. It has been reported that 21%–38% of patients with stroke have aphasia in the acute stage (Engelter et al., 2006). However, these neuroimaging modalities are limited in that they cannot reconstruct and estimate neural tracts. In contrast, DTT, a 3D visualized version of DTI, allows 3D visualization of the architecture and integrity of neural tracts at the subcortical level (Assaf and Pasternak, 2008). However, little is known about the usefulness of DTT for the AF, which is the important neural tract for language, connecting Wernicke and Broca areas, in predicting the aphasia outcome in patients with stroke, though few studies have demonstrated the clinical usefulness of DTT for AF (Breier et al., 2008). In the current study, we investigated aphasia outcome according to DTT findings for AF in early-stage stroke, we also identified different types of aphasia in relation to their precise anatomical localization (Clinico-radiological correlation). All patients were subjected to the following; Careful history taking, clinical examination, routine laboratory investigations for risk factors, language assessment using Modified comprehensive aphasia test, with resultant mean T-score AQ at onset and Three month later. Radiological assessment:CT brain:Conventional (Non-enhanced MRI) of the brain,3D Diffusion Tensor Tractography (DTT) and The following results were obtained:That patients with stroke in whom the left AF could not be reconstructed due to its severe injury showed worse prognosis; in contrast, patients with stroke whose left AF could be reconstructed revealed better prognosis. Global aphasia showed lower rates of recovery while better recovery was observed in Broca's aphasia as there was significant percent change in AQ test in both types respectively. Transcortical sensory aphasia had a worse prognosis than Broca's or Transcortical motor aphasia