A cannula and electrode assembly including: a cannula, including a cannula body having: opposed proximal and distal ends; a distal section that is electrically conductive, the distal section defining the distal end of the cannula body; a lumen that extends distally and longitudinally from the proximal end of the cannula body, the lumen dimensioned to receive the body of an electrode; and a side opening that is spaced proximally from the distal end of the cannula body, the side opening opening up into the cannula body lumen, wherein the cannula body is further formed so that: a bend is located in the body proximal to the cannula distal section; the body lumen extends to and through the bend and the body distal section; the side opening is formed so as to extend through a portion of the cannula body that defines an outer portion of said bend, and the cannula and electrode assembly further including: an electrode adapted for connection to a cable that connects the electrode to a control console, the electrode having an electrode body dimensioned to seat in the lumen of the cannula body, the electrode body having: a distal section formed from electrically conductive material that is electrically connected to a conductor internal to the cable and a section proximal to the distal section formed from elastic material, characterized in that the electrode body is formed so that a section formed from elastic material is located so that, when the electrode body is inserted in the cannula lumen, the section is within the section of the lumen defined by the bend and the electrode body section is shaped to define a bend so that, depending on the rotational orientation of the electrode body relative to the cannula body, when the electrode body is inserted in the cannula body the electrode body distal section either seats in the lumen portion within the cannula body distal section or extends out of the cannula body side opening. a cannula, including a cannula body having: opposed proximal and distal ends; a distal section that is electrically conductive, the distal section defining the distal end of the cannula body; a lumen that extends distally and longitudinally from the proximal end of the cannula body, the lumen dimensioned to receive the body of an electrode; and a side opening that is spaced proximally from the distal end of the cannula body, the side opening opening up into the cannula body lumen, wherein the cannula body is further formed so that: a bend is located in the body proximal to the cannula distal section; the body lumen extends to and through the bend and the body distal section; the side opening is formed so as to extend through a portion of the cannula body that defines an outer portion of said bend, an electrode adapted for connection to a cable that connects the electrode to a control console, the electrode having an electrode body dimensioned to seat in the lumen of the cannula body, the electrode body having: a distal section formed from electrically conductive material that is electrically connected to a conductor internal to the cable and a section proximal to the distal section formed from elastic material, characterized in that the electrode body is formed so that a section formed from elastic material is located so that, when the electrode body is inserted in the cannula lumen, the section is within the section of the lumen defined by the bend and the electrode body section is shaped to define a bend so that, depending on the rotational orientation of the electrode body relative to the cannula body, when the electrode body is inserted in the cannula body the electrode body distal section either seats in the lumen portion within the cannula body distal section or extends out of the cannula body side opening.