Treatment and/or prophylaxis, in mammalian patients, of neurodegenerative and other neurological medical disorders is effected by administering to the patient effective amounts of apoptotic bodies and/or apoptotic cells, preferably those derived from the patient's own white blood cells, e.g. by extracorporeal treatment of the patient's blood cells to induce apoptosis and administration of the apoptotic bodies and/or cells so formed to the patient.