Surgical and medical apparatus and instruments; medical implants; implants for neurostimulation; apparatus for stimulating nerves; electrical neurostimulators; medical devices for the diagnosis and treatment of headaches and related disorders, as well as component parts thereof; electrostimulation devices for treatment of headache and related disorders, i.e. implantable muscle or nerve stimulators consisting of artificial materials, and devices for implanting stimulators; medical devices for activating implantable stimulators; medical devices for wireless activation of implantable stimulators; medical devices with rechargeable batteries for implantable stimulator activation; medical devices, namely, external stimulators for implantable stimulator activation; patient screening kits for diagnosis of headache and related disorders, consisting of medical devices for diagnosis of headache and related disorders, electronic data recorders for recording information collected in the diagnosis of headache and related disorders, and computer software for management of data for use with medical devices for diagnosis of headache and related disorders, all sold as a set; electrical stimulation systems for medical use