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Updated: Aug 20, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Time course of wallerian degeneration after ischaemic stroke revealed by diffusion tensor imaging
G Thomalla1, V Glauche, C Weiller
1Neuroimage Nord, Klinik und Poliklinik für Neurologie, Universitätsklinikum Hamburg-Eppendorf, D-20246 Hamburg, Germany. thomalla@uke.uni-hamburg.de
Abstract:
Wallerian degeneration (WD) after ischaemic stroke is a well known phenomenon following a stereotypical time course. Whereas conventional magnetic resonance imaging fails to detect signal intensity changes until four weeks after stroke, diffusion tensor imaging (DTI) reveals changes related to WD only after days. DTI was used to monitor the time course of Wallerian degeneration of the pyramidal tract from the early subacute to the late chronic stage of ischaemic stroke in two patients. A progressive decrease of fractional anisotropy was found along the pyramidal tract in the cerebral peduncle below the primary lesion resulting from progressive changes in the principal diffusivities, as well as a slight increase in the orientationally averaged diffusivity in the chronic phase. These signal changes reflect the progressive disintegration of fibre structures resulting from WD.
Insights
Wallerian degeneration (WD) after ischemic stroke shows detectable changes with diffusion tensor imaging (DTI) within days. DTI reveals progressive fiber disintegration along the pyramidal tract, offering earlier insights than conventional MRI.
Area of Science:
- Neuroscience
- Radiology
- Neurology
Background:
- Wallerian degeneration (WD) is a known post-stroke process with a defined timeline.
- Conventional MRI detects WD changes late (weeks), while diffusion tensor imaging (DTI) offers earlier detection.
Purpose of the Study:
- To monitor the temporal progression of Wallerian degeneration in the pyramidal tract after ischemic stroke.
- To investigate the utility of DTI in characterizing early and late-stage WD changes.
Main Methods:
- Diffusion Tensor Imaging (DTI) was employed to track changes in the pyramidal tract.
- Two patients with ischemic stroke were monitored from the subacute to chronic stages.
Main Results:
- A progressive decrease in fractional anisotropy was observed along the pyramidal tract.
- Changes in principal diffusivities and a slight increase in averaged diffusivity were noted in the chronic phase.
- These DTI findings correlate with the structural disintegration characteristic of WD.
Conclusions:
- DTI can detect Wallerian degeneration earlier than conventional MRI.
- DTI provides valuable insights into the microstructural changes occurring during WD progression after ischemic stroke.
