Table 3
Simpson classification of extent of resection [10]

Grade	Extent of resection
I	Macroscopic total resection of tumor, dural attachments and abnormal bone
II	Macroscopic total resection of tumor, coagulation of dural attachments
III	Macroscopic total resection without resection or coagulation of dural attachments or of its extradural extension
IV	Partial resection of tumor
V	Simple decompression (biopsy)