Tractography Alterations in the Arcuate and Uncinate Fasciculi in Post-Stroke Aphasia

Abstract

Fiber tractography based on diffuse tensor imaging (DTI) can reveal three-dimensional white matter connectivity of the human brain. Tractography is a non-invasive method of visualizing cerebral white matter structures in vivo, including neural pathways surrounding the ischemic area. DTI may be useful for elucidating alterations in brain connectivity resulting from neuroplasticity after stroke. We present a case of a male patient who developed significant mixed aphasia following ischemic stroke. The patient had been treated by mechanical thrombectomy followed by an early rehabilitation, in conjunction with transcranial direct current stimulation (tDCS). DTI was used to examine the arcuate fasciculus and uncinate fasciculus upon admission and again at three months post-stroke. Results showed an improvement in the patient’s symptoms of aphasia, which was associated with changes in the volume and numbers of tracts in the uncinate fasciculus and the arcuate fasciculus.

Changes in the Brain Connectome Following Repetitive Transcranial Magnetic Stimulation for Stroke Rehabilitation

“…Neuroplasticity associated with the recovery and associated changes in tractography have been previously demonstrated in post-stroke patients [ 17 ]. Tract integrity may even serve as a biomarker for post-stroke recovery [ 18 ].…”

Diffusion Tensor Tractography Studies on Recovery Mechanisms of Aphasia in Stroke Patients: A Narrative Mini-Review

“…By contrast, the recently developed diffusion tensor tractography (DTT), derived from diffusion tensor imaging (DTI), has a unique advantage due to its ability to visualize and estimate the language-related neural tracts at the subcortical level [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. The main advantage of DTT is that the entire neural tract can be evaluated using the DTT parameters (fractional anisotropy [FA], mean diffusivity, and fiber number) and configurational analysis [ 31 , 32 , 33 ].…”

“…The main advantage of DTT is that the entire neural tract can be evaluated using the DTT parameters (fractional anisotropy [FA], mean diffusivity, and fiber number) and configurational analysis [ 31 , 32 , 33 ]. As a result, serial DTTs for the language-related neural tracts during the improvement phase appear to be appropriate for the elucidation of the mechanisms of aphasia recovery in them [ 8 , 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 34 , 35 , 36 ]. A significant number of DTT-based studies have reported on the recovery mechanisms of aphasia in various brain pathologies including stroke, traumatic brain injury, and brain tumor [ 8 , 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 34 , 35 , 36 ].…”

“…As a result, serial DTTs for the language-related neural tracts during the improvement phase appear to be appropriate for the elucidation of the mechanisms of aphasia recovery in them [ 8 , 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 34 , 35 , 36 ]. A significant number of DTT-based studies have reported on the recovery mechanisms of aphasia in various brain pathologies including stroke, traumatic brain injury, and brain tumor [ 8 , 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 34 , 35 , 36 ]. The majority of the above studies have reported on stroke patients with aphasia [ 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ].…”

“…A significant number of DTT-based studies have reported on the recovery mechanisms of aphasia in various brain pathologies including stroke, traumatic brain injury, and brain tumor [ 8 , 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 34 , 35 , 36 ]. The majority of the above studies have reported on stroke patients with aphasia [ 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. However, there has been no review article on this topic in stroke.…”