This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
Pronator drip is a sign of 
Select and explain. 
A. UMN lesion of upper limb, B. LMN lesion, C. Dorsal syringomyelia, D. Carpel tunnel syndrome
A: UMN lesion of upper limb
Answer: A: UMN lesion of upper limb 
Explanation: In medicine, pronator drift refers to a pathologic sign seen during a neurological examination. Jean Alexandre Barre is credited with having first described it; thus it is sometimes known as the Barre test or sign. A positive result indicates spasticity seen in UMN lesion of upper limb Ref Harrison20th edition pg 2345