Macrocerebellum, also known as cerebellar hyperplasia, refers to a rare condition characterised by an abnormally enlarged cerebellum with preserved architecture and shape. It is usually demonstrated on imaging with a thickening of the cortical gray matter of the cerebellar hemispheres.
Macrocerebellum is a rare imaging finding, only a few case have been reported 3.
It is usually dependent on the underlying disease. Hypotonia, ataxia, and ocular movement disorders are related in patients with a isolated macrocerebellum 1,2.
The aetiology is unknown. For some authors it is not considered an independent entity, but a manifestation of different conditions 2,3. For others is a cerebellar response to the elaboration of growth factors intended to augment the slow development of cerebral structures 1.
It can be found as an isolated (non-syndromic) condition or as part of well-defined syndrome, such as Costello syndrome and Sotos syndrome, or neurometabolic diseases (e.g. mucopolysaccharidosis type I and II) 2.
There is no malformation, only a diffusely enlarged cerebellum, especially due to cerebellar hemispheres cortical gray matter 2,3.
- 1. Bodensteiner JB, Schaefer GB, Keller GM et-al. Macrocerebellum: neuroimaging and clinical features of a newly recognized condition. J. Child Neurol. 1997;12 (6): 365-8. Pubmed citation
- 2. Bosemani T, Orman G, Boltshauser E et-al. Congenital abnormalities of the posterior fossa. Radiographics. 2015;35 (1): 200-20. doi:10.1148/rg.351140038 - Pubmed citation
- 3. Poretti A, Mall V, Smitka M et-al. Macrocerebellum: significance and pathogenic considerations. Cerebellum. 2012;11 (4): 1026-36. doi:10.1007/s12311-012-0379-1 - Pubmed citation