This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Which of the following is not a feature of extramedullary syndrome? 
Select and explain. 
A. Root pain, B. Sacral sparing, C. Abnormal, D. Early coicospinal tract involvement
B: Sacral sparing
Answer: B: Sacral sparing 
Explanation: Intramedullary tumors arising from the central pa of the cord often spare sensation over the sacral region ("sacral sparing") because of the somatotopic organization of the spinal cord, in which the sacral sensory fibers are at the most peripheral position within the spinal cord. Ref Davidson 23rd edition pg 455