@article {zhao_does_2010,
	title = {Does MRI lesion activity regress in secondary progressive multiple sclerosis?},
	journal = {Multiple Sclerosis},
	volume = {16},
	year = {2010},
	pages = {434-442},
	abstract = {<p>Background: The rate of new contrast-enhancing lesions (CELs) on monthly magnetic resonance imaging (MRI) scans has been shown to decrease over a 9-month period in placebo-treated patients with relapsing{\textendash}remitting (RR) multiple sclerosis (RRMS). Objective: We examined this phenomenon in placebo-treated secondary progressive MS (SPMS) patients. Methods: Patients were chosen from two clinical trials. Monthly scans were taken at screening, baseline and months 1{\textendash}9 for Cohort-1 and months 1{\textendash}6 for Cohort-2. We examined the monthly new CEL rates according to initial CEL level: 0, 1{\textendash}3, \&gt;3 CELs at screening, and presence and absence of pre-study relapses. Results:Respectively, 59, 21 and 14 of the 94 Cohort-1 patients, and 36, 17 and 9 of the 62 Cohort-2 patients had 0, 1{\textendash}3 and \&gt;3 initial CELs. For Cohort-1, the monthly new CEL rates did not change during follow-up, regardless of initial CEL level. For Cohort-2, the monthly rate was unchanged in the 0 initial CEL subgroup, but decreased 33\% (95\% confidence interval: 8\%, 52\%) from months 1{\textendash}3 to months 4{\textendash}6 in the other two subgroups. For the combined cohorts, a decreasing rate was observed in the 12 patients with \&gt;3 initial CELs and pre-study relapses. Conclusions: The short-term trend of new CEL activity in placebo-treated SPMS patients may vary across cohorts.</p>
},
	doi = {10.1177/1352458509359726},
	url = {http://msj.sagepub.com/content/early/2010/02/18/1352458509359726},
	author = {Zhao, Y. and Petkau, A.John and Traboulsee, A. and Riddehough, A. and Li, D. K. B.}
}
