Methods and related systems for modulating neural activity by cyclical blocking of conduction in peripheral neural structures are disclosed. Neural activity may blocked cyclically by blocking stimuli delivered via various types of blocking stimulus sources. In an aspect, a conduction block is produced in a sensory nerve. Neural modulation may be used, for example, to modulate an undesired sensation, such as pain, or an immune or inflammatory response or process. Delivery of blocking stimuli may be controlled in part in response to an input from a user input device.