The NEDA criteria

The NEDA (No Evidence of Disease Activity) criteria are commonly used in everyday clinical practice in order to define the activity of multiple sclerosis. NEDA is defined as the absence of new or enlarging T2 lesions or T1 gadolinium-enhancing lesions on MRI and no sustained Expanded Disability Status Scale (EDSS) score progression or clinical relapse. The rate of brain volume loss is recently proposed as an additional criterion for the definition of NEDA. Fulfilling NEDA criteria may be a useful outcome measure of disease-modifying therapy (DMT) as well as a treatment goal in clinical practice.
 
References:
1. Rotstein DL, Healy BC, Malik MT, Chitnis T, Weiner HL. Evaluation of No Evidence of Disease Activity in a 7-Year Longitudinal Multiple Sclerosis Cohort. JAMA Neurol. 2015;72(2):152-158.
2. Giovannoni, Gavin et al. Is it time to target no evident disease activity (NEDA) in multiple sclerosis?Multiple Sclerosis and Related Disorders , Volume 4 , Issue 4 , 329 - 333
3. Kappos L et al.  Abstract  116. Presented   at: The European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) Congress; Oct. 7-10, 2015; Barcelona.