A surgical tool for penetrating tissue and monitoring the proximity of neural elements, comprising: a needle assembly extending along a longitudinal axis, said needle assembly comprising: a stylet including an electrically conductive portion near a pointed distal end, a shaft extending proximally from said distal end providing a conductive path to a proximal extension of said stylet; a cannula including an insulated outer surface area and a length wherein said pointed distal end of said stylet projects distally from said insulated surface area when said stylet is positioned in said cannula; a handle assembly attachable near said proximal end of said needle assembly comprising: an electrically insulated outer surface area; an electrically conductive area internal to said electrically insulated outer surface area and engageable with said proximal extension of said stylet; and an electrical lead; characterised in that said handle assembly includes a gripping portion having a major dimension at least 50% greater than a minor dimension, said major and minor dimensions (83, 85) being measured orthogonally to said longitudinal axis and to one another; and said electrical lead extends from said electrically conductive area through said handle assembly along said major dimension; wherein said handle assembly includes a handle body having a bore extending along said major dimension from a lateral outer surface of said handle body to a receptacle aligned along said longitudinal axis of said needle assembly when said handle assembly is engaged thereto, said lead extending through said bore; and wherein the surgical tool further comprises a body positionable in said bore, said body defining a trough for receiving a cable portion of said lead and securing said cable portion in said handle assembly, where the body includes axial protrusions and lateral protrusions projecting into the trough for engaging the cable and maintaining it in position in the trough. a needle assembly extending along a longitudinal axis, said needle assembly comprising: a stylet including an electrically conductive portion near a pointed distal end, a shaft extending proximally from said distal end providing a conductive path to a proximal extension of said stylet; a cannula including an insulated outer surface area and a length wherein said pointed distal end of said stylet projects distally from said insulated surface area when said stylet is positioned in said cannula; a stylet including an electrically conductive portion near a pointed distal end, a shaft extending proximally from said distal end providing a conductive path to a proximal extension of said stylet; a cannula including an insulated outer surface area and a length wherein said pointed distal end of said stylet projects distally from said insulated surface area when said stylet is positioned in said cannula; a handle assembly attachable near said proximal end of said needle assembly comprising: an electrically insulated outer surface area; an electrically conductive area internal to said electrically insulated outer surface area and engageable with said proximal extension of said stylet; and an electrically insulated outer surface area; an electrically conductive area internal to said electrically insulated outer surface area and engageable with said proximal extension of said stylet; and an electrical lead; characterised in that said handle assembly includes a gripping portion having a major dimension at least 50% greater than a minor dimension, said major and minor dimensions (83, 85) being measured orthogonally to said longitudinal axis and to one another; and said electrical lead extends from said electrically conductive area through said handle assembly along said major dimension; wherein said handle assembly includes a handle body having a bore extending along said major dimension from a lateral outer surface of said handle body to a receptacle aligned along said longitudinal axis of said needle assembly when said handle assembly is engaged thereto, said lead extending through said bore; and wherein the surgical tool further comprises a body positionable in said bore, said body defining a trough for receiving a cable portion of said lead and securing said cable portion in said handle assembly, where the body includes axial protrusions and lateral protrusions projecting into the trough for engaging the cable and maintaining it in position in the trough.