A device for treating one or more symptoms associated with Restless Legs Syndrome or Periodic Limb Movement Disorder (PLMD) using high-frequency electrostimulation, the device comprising: external electrostimulation electrodes (110A, 110B, 110C), configured to be affixed to a subject at an external location associated with at least one of, or at least one branch (102A, 102B, 102C) of, a sural nerve or a peroneal nerve to deliver electrostimulation thereto; an electrostimulation generator circuit, adapted to be coupled to the electrostimulation electrodes (110A, 110B, 110C) to generate the electrostimulation for delivery by the electrostimulation electrodes (110A, 110B, 110C), wherein the electrostimulation generator circuit includes an AC electrostimulation generator circuit, configured to generate, for delivery to the external location via the electrostimulation electrodes, an electrostimulation signal at a frequency that exceeds 500 Hz and is less than 15,000 Hz and a current that exceeds 5mA and is less than 30 mA, to help reduce or alleviate the one or more symptoms associated with RLS or PLMD; and a controller circuit, coupled to the electrostimulation generator circuit, the controller circuit configured to initiate therapy using an initial set of electrostimulation parameter values based on efficacy of previous RLS or PLMD therapy in the patient, and/or configured for controlling initiation, titration, or adjustment of electrostimulation therapy based on sensor information received from one or more sensors to detect when RLS or PLMD symptoms are present, or to detect a physiological indicator indicating susceptibility to or aggravation of RLS or PLMD symptoms. external electrostimulation electrodes (110A, 110B, 110C), configured to be affixed to a subject at an external location associated with at least one of, or at least one branch (102A, 102B, 102C) of, a sural nerve or a peroneal nerve to deliver electrostimulation thereto; an electrostimulation generator circuit, adapted to be coupled to the electrostimulation electrodes (110A, 110B, 110C) to generate the electrostimulation for delivery by the electrostimulation electrodes (110A, 110B, 110C), wherein the electrostimulation generator circuit includes an AC electrostimulation generator circuit, configured to generate, for delivery to the external location via the electrostimulation electrodes, an electrostimulation signal at a frequency that exceeds 500 Hz and is less than 15,000 Hz and a current that exceeds 5mA and is less than 30 mA, to help reduce or alleviate the one or more symptoms associated with RLS or PLMD; and a controller circuit, coupled to the electrostimulation generator circuit, the controller circuit configured to initiate therapy using an initial set of electrostimulation parameter values based on efficacy of previous RLS or PLMD therapy in the patient, and/or configured for controlling initiation, titration, or adjustment of electrostimulation therapy based on sensor information received from one or more sensors to detect when RLS or PLMD symptoms are present, or to detect a physiological indicator indicating susceptibility to or aggravation of RLS or PLMD symptoms.