The Fleece of Stilling: History of cerebellar white matter

Introduction: The cerebellum harbours different functions, ranging from motor to cognitive and linguistic skills. This complex functional landscape is founded on a specific architecture of intracerebellar white matter fibres surrounding the dentate nucleus, extremely difficult to visualize with modern imaging techniques. Though, surgeons may greatly benefit from detailed knowledge of this anatomy. Historical studies have proved how anatomical dissections allow an accurate study of intracerebellar white matter bundles, providing essential information about the relations between dentate nucleus, cerebellar cortex and cerebellar peduncles. Throughout the centuries, the concept of dentate capsule, the so-called Fleece of Stilling, has been demonstrated by multiple authors but has been neglected in recent times. Materials and Methods: Extensive historical literature research was conducted through multiple digital libraries, searching for complete digitalized works of selected historical anatomists, with the specific goal of reconstructing the evolution of knowledge relative to intracerebellar white matter architecture from the end of the XVIIth century to recent years. Key authors have been selected, and their original works were studied and reviewed. Results: Essays and atlases from Vieussens, Malacarne, Vicq d’Azyr, Reil, Meckel the Younger, Arnold, Stilling, Cajal, Dejerine and Jakob were collected. Their anatomical descriptions and illustrations were discussed and detailed, demonstrating their discoveries about intracerebellar white matter anatomy. Conclusion: Information deriving from studies performed by the major anatomists of the past highlights pivotal anatomical data. Integration of this knowledge with information gained through modern imaging technologies may have an important impact on surgeries of the cerebellum and cerebellum associated structures.