Electrosurgical tissue treatment device

A device for treating spinal tissue of a patient's body may include an energy source and first and second probe assemblies. Each of the probe assemblies may have an electrically conductive energy delivery device electrically coupled to the energy source, and may also have an electrothermal device for cooling the probe assembly. The device is configured so that the energy source delivers energy to the spinal tissue through the energy delivery devices in a bipolar mode that concentrates delivered energy between the energy delivery devices to create a lesion within the spinal tissue while the electrothermal devices cool the probe assemblies. Related methods of use include cooling, at times via an electrothermal device.