US Patent 10881858 Electrical substance clearance from the brain

Apparatus is provided that includes an extracranial electrode, configured to be placed outside and in electrical contact with a skull of a subject identified as at risk of or suffering from a disease; and a cerebrospinal fluid (CSF) electrode, configured to be implanted in a ventricular system of a brain of the subject. Control circuitry is configured to drive the extracranial and the CSF electrodes to clear a substance from brain parenchyma of the subject into the ventricular system of the brain. Other embodiments are also described.