Implantable medical devices (IMD) configured for implantation within a recess formed in a cranium of a patient, as well as associated methods, are described. In some embodiments, the IMD includes a top external surface and another adjacent external surface, e.g., a side surface, which are oriented with respect to each other to define an acute angle. A connection module for an electrical lead or catheter may be included on the top external surface. Embodiments of the invention may facilitate implantation of an IMD within a recess formed in the cranium of a patient at a location remote to an incision made in the scalp of the patient.