Validating the use of brain volume cutoffs to identify clinically relevant atrophy in RRMS.
BACKGROUND
Baseline brain volume (BV) is predictive at a group level but is difficult to interpret at the single patient level.


OBJECTIVE
To validate BV cutoffs able to identify clinically relevant atrophy in relapsing-remitting multiple sclerosis (RRMS) patients.


METHODS
The expected normalized brain volume (NBV) for each patient was calculated using RRMS patients from two phase III clinical trials, applying a linear formula developed on the baseline variable of an independent data set. The difference between these expected NBV values and those actually observed was calculated and used to categorize the patients in the low-NBV, medium-NBV, and high-NBV groups.


RESULTS
The 2-year probability of 3-month confirmed disability worsening was significantly associated with the NBV categorization ( p = 0.006), after adjusting for treatment effect. Taking the high-NBV group as a reference, the hazard ratios for the medium-NBV and low-NBV groups were 1.22 (95% confidence interval (CI): 0.85-1.76, p = 0.27) and 1.69 (95% CI: 1.11-2.57, p = 0.01), respectively.


CONCLUSION
This study validates the use of BV cutoffs to identify clinically relevant atrophy in RRMS study by showing that the three groups classified according to the baseline NBV adjusted for the other prognostic variables have a significant prognostic impact on the risk of disability progression.
['Bovis|Francesca|F|', 'De Stefano|Nicola|N|', 'Steinerman|Joshua R|JR|', 'Knappertz|Volker|V|', 'Sormani|Maria Pia|MP|']
D000328:Adult D001284:Atrophy D001921:Brain D005260:Female D006801:Humans D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D020529:Multiple Sclerosis, Relapsing-Remitting D016032:Randomized Controlled Trials as Topic D012016:Reference Values
Multiple sclerosis normalized brain volume disability progression laquinimod