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
A patient has preserved light touch and absent pain and temperature over the left upper limb. This pattern of sensory loss is called- 
Select and explain. 
A. Stock and glove type, B. Segmental type, C. Dissociated type, D. Mononeuritis type
C: Dissociated type
Answer: C: Dissociated type 
Explanation: Dissociated sensory loss describes the loss of pain and temperature sensation resulting from involvement of the crossing of spinothalamic second-order neurons, with sparing of dorsal column function. Worsening spasticity is attributable to increasing involvement of the descending coicospinal tracts Ref Harrison20th edition pg 2236