Microdissection of Medial Brain White Matter: Two-Dimensional Video Overview

Overview

This report presents a structured, stepwise microdissection of the medial brain white matter, focusing on the limbic lobe and its fiber systems. A supplementary annotated video enhances understanding of the complex anatomy, highlighting key sulcal, gyral, and white matter structures essential for neurosurgical planning.

Background

Microdissection of cerebral white matter has become a vital technique for exploring the three-dimensional organization of brain structures. The medial brain surface, particularly the limbic lobe, is crucial for memory, emotion, and behavior, yet its detailed dissection has been less frequently documented compared to the lateral surface. Precise anatomical knowledge of this region aids in understanding tumor compartmentalization and facilitates safer microneurosurgical interventions. This work fills a gap by providing a comprehensive, video-based demonstration of medial hemispheric dissection.

Data Highlights

The dissection was performed on a single hemisphere prepared by the senior author using the Klingler protocol: fixation in 10% formalin for at least two months, freezing at –10 to –15 °C for a minimum of one week, and thawing before dissection. The procedure utilized microscopic visualization with a Zeiss OPMI Pentero surgical microscope and involved careful removal of cortex and U-fibers to expose deeper white matter tracts such as the cingulum and callosal fibers. Key anatomical landmarks identified include the cingulate pole, medial paraolfactory gyrus, paraterminal gyrus, rostral gyrus, cingulate gyrus, precuneus, isthmus, parahippocampal gyrus, and fusiform gyrus.

Key Findings

• The medial brain surface dissection begins with detailed identification of sulcal and gyral landmarks, emphasizing the limbic lobe's continuous cortical arch from the subcallosal area to the parahippocampal region.
• Decortication requires careful removal of the thin limbic mesocortex and its thinner U-fiber layer to avoid damage to underlying white matter.
• Removal of U-fibers and the cingulum exposes the callosal fibers and inferior longitudinal fasciculus (ILF), with the cingulum divided into anterior and posterior portions at the cuneus apex.
• The parieto-occipital fissure is a deep, consistently uninterrupted landmark important for orientation during dissection.
• The approach integrates technical tips from the Zurich laboratory experience, enhancing educational clarity through video annotation and schematic overlays.

Clinical Implications

Understanding the detailed anatomy of medial brain white matter and limbic structures is critical for neurosurgeons managing deep-seated lesions and intrinsic tumors confined within limbic boundaries. The stepwise dissection technique aids in preserving vital fiber tracts and optimizing surgical planning. The video-based educational tool supports improved anatomical comprehension for both research and clinical training.

Conclusion

This work provides a comprehensive, didactic overview of medial brain white matter microdissection, filling a literature gap with a detailed video demonstration. It enhances anatomical understanding crucial for neurosurgical applications involving the limbic lobe and medial hemispheric structures.

References

1. C.S. et al. 2025 -- Microdissection of Medial Brain White Matter: A Two-Dimensional Video Overview