Comment on Salman M: Posterior fossa decompression and the cerebellum in Chiari type II malformation: a preliminary MRI study.

We review a paper by Dr. Salman on the role and timing of posterior fossa decompression in Chiari 2 malformation (C2M) associated with myelomeningocele, based on a volumetric study of the posterior fossa in operated vs non-operated patients. This paper states that, although CSF spaces were increased after posterior fossa decompression (PFD), cerebellar atrophy was not prevented by surgery and concludes that early PFD in newborns could prevent cerebellar atrophy. In the discussion, we point at the small size of patient samples and dissimilarity of the groups, which might underscore the radiological results, and regret the lack of clinical correlation with the radiological data and of the information on the shunt status in the two groups. We conclude that the author's conclusions regarding the timing and efficiency of ultra-early PFD in patients with C2M are not supported by his data. © Springer-Verlag 2011