A medically implantable lead configured for insertion into a human or animal body to be attached in the body with its distal end to tissue inside the body, as a rotatable helix at a distal end thereof that can be screwed into the tissue. The helix serves as an attachment of the lead to the tissue as well as a conductor for conducting electrical signals to the tissue through electrically conducting surfaces on the helix. The surfaces of the helix are partly insulated so as to restrict the conducting of signals between the helix and the tissue to desirable regions. The surfaces of the helix facing inwardly, toward an inner bore of the helix, are electrically insulated. In a method for manufacturing such a lead, the wire forming the helix has protrusions in desired areas and the wire including the protrusions is coated with an electrically insulating layer. The protrusions are uncovered from the insulating layer in desired regions.