grade I : involves grey-white matter interfaces most commonly : parasagittal regions of frontal lobes, periventricular temporal lobes less commonly : parietal and occipital lobes, internal and external capsules, and cerebellum often inapparent on conventional imaging may have changes on MRS 3
grade II : involves corpus callosum in addition to stage I locations observed in approximately 20% of patients most commonly : posterior body and splenium but does advance anteriorly with increasing severity of injury most frequently unilateral may be seen on SWI 3
grade III : involves brainstem in addition to stage I and II locations most commonly : rostral midbrain, superior cerebellar peduncles, medial lemnisci and corticospinal tracts.
When Brainlab first introduced neurosurgery software in 1989, a neurosurgeon who needed software was viewed as not a good neurosurgeon. Today, a neurosurgeon who does certain procedures without the proper software is viewed as not a good neurosurgeon.