How do CACI Facials work? The clinically proven facial treatment has been around for 25 years and is a muscle lifting procedure that uses microcurrent technology to send out tiny electrical impulses helping to tone and soften facial expressions. A microcurrent electrical neuromuscular stimulator or MENS (also microamperage electrical neuromuscular stimulator) is a device used to send weak electrical signals into the body. INTRODUCTION. Bell's palsy is the appellation commonly used to describe an acute peripheral facial palsy of unknown cause. However, the terms "Bell's palsy" and "idiopathic facial paralysis" may no longer be considered synonymous, as herpes simplex virus activation is the likely cause of Bell's palsy in most cases.