If a single spinal nerve is cut, the area of tactile loss is always greater than the area of loss of painful sensations, because:
C i.e. Degree of overlap of fibres carrying tactile sensation is much less. - Degree of overlap of fibres is much lessQ - Greater Overlap of pain sensory units. - Lack of collateralization from adjacent tactile fibres - Rapid collateral regeneration of pain fibres Sensory changes due to interruption of a single peripheral nerve vary, depending on whether the nerve involved is predominantly muscular, cutaneous or mixed. Following injury to a cutaneous nerve, the area of sensory loss is always less than its anatomic distribution because of overlap from adjacent nerve. But area of sensory loss for touch > painQ.