Lesion length may not predict pediatric MS

This retrospective study found that lesion extent alone may not be a satisfactory tool for diagnosing multiple sclerosis in children. 

The authors reported on the frequency of longitudinally extensive lesions in children presenting to a multiple sclerosis center with optic neuritis. Lesion length, determined by T2 hyperintensity or contrast enhancement, was blindly graded as absent, focal or longitudinally extensive, which was defined as contiguous involvement in at least two of four segments of the optic nerve.

Of 25 subjects, 9 (36 percent) had longitudinally extensive optic neuritis. One-third of patients ultimately diagnosed with relapsing remitting multiple sclerosis had presented with longitudinally extensive optic neuritis. The authors found no association between lesion extent and nonmultiple sclerosis diagnoses, such as neuromyelitis optica, although the confidence interval was too wide to be conclusive.

They write that given the frequency of extensive optic nerve lesions in these subjects with relapsing remitting multiple sclerosis and that multiple sclerosis was more common than other diagnoses, lesion extent might not be a satisfactory criterion for predicting neuromyelitis optica or other nonmultiple sclerosis diagnoses in children with first optic neuritis events. They also found no association between age and lesion extent. 

They conclude that prospective studies are needed to determine if longitudinally extensive optic neuritis can predict visual outcome and whether known genetic or environmental risk factors for demyelinating disease affect lesion size and severity.