White Matter Disconnection
1. Definition
- White matter disconnection is the disruption of neural pathways linking different brain regions, caused by injury, disease, or surgery.
2. Causes
| Cause | Examples |
|---|---|
| Trauma | Diffuse axonal injury |
| Surgery | Resection of brain tissue (e.g., epilepsy surgery) |
| Stroke | Ischemic damage to white matter tracts |
| Tumors | Compression or infiltration of tracts |
| Neurodegeneration | Multiple sclerosis, Alzheimer's disease |
3. Consequences
- Memory impairment (e.g., disconnection of hippocampal tracts). - Language deficits (e.g., arcuate fasciculus injury). - Motor weakness (e.g., corticospinal tract disruption). - Executive dysfunction (e.g., frontoparietal pathway damage).
4. In Epilepsy Surgery
- Cognitive decline may occur due to injury to white matter pathways even when gray matter resection is limited. - Key affected tracts:
5. Assessment Techniques
| Method | Description |
|---|---|
| Diffusion Tensor Imaging (DTI) | Maps white matter tracts via water diffusion |
| Tractography | 3D reconstruction of pathways |
| Lesion-symptom mapping | Correlation between injury site and clinical symptoms |
Summary
White matter disconnection disrupts brain network communication, leading to functional impairments. Preserving critical white matter tracts is essential in neurosurgery and neurorehabilitation.