A patient has preserved light touch and absent pain and temperature over the left upper limb. This pattern of sensory loss is called-

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