to the patient 39 s skull using an exterior threaded structure that fits into threads formed in the burr hole of the patient as an example cap base 101 further includes opening 112 through which the lead exits from the burr hole cap 100 to be coupled to a pulse generator insert assembly 201 is shown in a disassembled form in fig2 according to one representative embodiment insert assembly 201 is adapted to be partially located within the burr hole of the patient and to be mechanically coupled with cap base 101 insert assembly 201 includes the components that enable a lead to be secured at a desired location anywhere within the burr hole as shown in fig2 insert assembly 201 comprises retainer 201 lead retainer 202 and housing structure 203 in preferred embodiments housing structure 203 and lead retainer 201 are shipped in a permanently coupled configuration with a distal portion of lead retainer 202 placed between the two components although the components could be connected at the time of surgery in alternative embodiments when mated housing structure 203 and lead retainer 201 define an annular channel in which a distal portion of lead retainer 202 sits preferably flange 204 of housing structure 203 comprises a lip shown in fig5 a on its underside and interior circumference a suitable structure e g a pivot pin 306 as shown in fig3 is preferably implemented on lead retainer 202 that extends into the space behind the lip accordingly the lip.