# Three-dimensional microsurgical anatomy of the cerebral hemisphere from medial to lateral: a fiber-dissection study

## TL;DR

This study provides a detailed 3D map of the cerebral hemisphere's inner structure, from the medial to lateral sides, using fiber dissection to improve neurosurgical understanding.

## Contribution

A systematic, layer-by-layer 3D anatomical characterization of cerebral hemisphere fiber tracts and nuclei from medial to lateral.

## Key findings

- The cerebral hemisphere has a consistent, reproducible arrangement of white-matter and deep nuclei layers.
- Commissural, association, and projection fibers show consistent spatial relationships across specimens.
- The study clarifies anatomical relationships that may improve neurosurgical precision and understanding of brain connectivity.

## Abstract

Accurate exposure of lesions on the medial cerebral hemisphere remains technically challenging, and current imaging cannot fully depict the subcortical intricate architecture extending from the medial surface outward. Although portions of this anatomy have been described, a comprehensive topographic characterization from medial to lateral is still lacking.

To provide a systematic, layer-by-layer topographic analysis of the white-matter fiber tracts and deep gray-matter nuclei from the medial surface to the lateral convexity of the cerebral hemisphere by combining stepwise fiber dissection with three-dimensional (3D) photography.

Twelve adult human cerebral hemispheres, fixed in 10% formalin and prepared with the Klingler fiber-dissection technique, were examined under 6× – 40 × magnification. Dissection commenced at the medial surface and proceeded outward, exposing commissural, association, and projection fibers as well as adjacent subcortical nuclei. High-resolution stereoscopic images were captured after each stage to document 3D spatial relationships.

From medial to lateral, the hemisphere comprised orderly layers of commissural, association, and projection systems interwoven with deep nuclei, forming a complex but reproducible arrangement in all specimens. The study provides complete medial exposure of these structures and demonstrates consistent positional relationships among different specimens.

This 3D fiber-dissection study offers the layer-by-layer depiction of the cerebral hemisphere from medial to lateral, clarifying spatial relationships among key white-matter bundles and deep nuclei. The anatomic insights gained may facilitate safer, more precise neurosurgical approaches and refine understanding of hemispheric connectivity.

The online version contains supplementary material available at 10.1007/s00701-026-06829-z.