An electrical amyloid beta-clearance system for treating a subject identified as at risk of or suffering from Alzheimer's disease is provided, the system including midplane treatment electrodes, adapted to be disposed over a superior sagittal sinus, outside and in electrical contact with a skull of a head of the subject; lateral treatment electrodes, adapted to be disposed between 1 and 12 cm of a sagittal midplane of the skull; and control circuitry, configured to clear amyloid beta from a subarachnoid space to the superior sagittal sinus, by applying one or more treatment currents between (a) one or more of the midplane treatment electrodes and (b) one or more of the lateral treatment electrodes. Other embodiments are also described.