Detection of cortical inflammatory lesions by double inversion recovery magnetic resonance imaging in patients with multiple sclerosis.

BACKGROUND

A significant inflammatory pathologic disorder in the cortex of patients with multiple sclerosis (MS) has been demonstrated by ex vivo studies.

OBJECTIVE

To determine the frequency, time of appearance, and clinical relevance of intracortical lesions (ICLs) in MS in vivo.

DESIGN

Double inversion recovery sequence study.

SETTING

Multiple Sclerosis Centre of the Veneto Region. Patients We enrolled 380 patients (116 with clinically isolated syndrome [CIS], 163 with relapsing-remitting MS [RRMS], and 101 with secondary progressive MS [SPMS]) and 40 age- and sex-matched healthy volunteers between May 1, 2005, and December 31, 2006.

MAIN OUTCOME MEASURES

We assessed the frequency and number of ICLs and brain parenchyma fraction, white matter T2 lesion volume, and clinical disability.

RESULTS

Although never observed in healthy volunteers, ICLs were detected in 58% of patients (36% of patients with CIS, 64% of patients with RRMS, and 73% of patients with SPMS). The number of ICLs was higher in patients with SPMS than in those with CIS or RRMS (P <.001), and patients with ICLs had a higher Expanded Disability Status Scale score (P = .004), a higher white matter T2 lesion volume (P = .008), a lower brain parenchyma fraction (P = .009), and a higher frequency of IgG oligoclonal bands (IgGOBs) (P <.001) than patients without ICLs. Patients positive for IgGOBs had more ICLs than patients negative for IgGOBs (P = .02). The number of ICLs correlated with the Expanded Disability Status Scale score (r = 0.48, P <.001), white matter T2 lesion volume (r = 0.38, P = .001), and brain parenchyma fraction (r = -0.47, P = .001). A significant association between ICLs and male sex was observed.

CONCLUSIONS

Although more frequent in patients with SPMS, ICLs were observed from the early disease stages. The ICLs were more frequently detected in patients with IgGOBs and were associated with a higher clinical disability score and male sex. The ICLs may help to define MS clinical heterogeneity and prognosis in clinical settings.