Contributions
Abstract: P490
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Brain atrophy occurs from the early phase of relapsing remitting (RR) MS and it is an important determinant of disease progression. We set out to explore factors affecting the rate of cortical thinning in the long-term.
Methods: Among 219 RRMS patients, followed from onset for 7.9 mean years, we used regression analysis to assess early factors affecting the rate of global cortical thickness (Cth) loss/year and predicting the most severe global cortical damage (worst 25Th percentile loss) over time.
Results: Within the observation period, 27% (59 of 219) of patients converted to secondary progressive (SP) MS, in 6.1 mean years; this subgroup had, at disease onset, significantly lower mean global Cth (SP=2.51 mm, RR=2.58 mm p=0.004) and higher number of cortical lesions (CLs) (SP=6.5, RR=1.8 mean lesions; p< 0.001), and displayed faster cortical thinning over time (SP=-1.31%/year, RR=-0.96%/year mean loss; p< 0.001). In the total population, at disease onset, a higher number of CLs was associated with a significantly lower mean global CTh (r = -0.188, p = 0.005). Factors associated with a larger proportion of grey matter loss/year were gender (male=-0.74%, female=-0.60%; p=0.03), number of CLs at onset (0 CLs=-0.56%, 1-3 lesions=-0.63%, 4-6 lesions=-0.73%, ≥7 lesions=-0.78%, p< 0.001) and number of relapses during the first two years (1 relapse=-0.47%, 2 relapses=-0.79%, ≥3 relapses=-0.94%; p< 0.001). The white matter lesions number at onset did not affect the rate of brain atrophy (lesions: ≤ 4=-0.68%, 5-8=-0.60%, 9-11=-0.67%, ≥12=-0.72%; p=0.13). In the multivariate model, a larger accumulation of CLs volume (OR=3.47; p=0.01), a more rapid cortical thinning during the first two years (OR=1.43; p=0.001), and ≥3 early relapses (OR=8.41; p< 0.001) independently predicted a higher risk of more severe global Cth loss at the end of the follow up.
Conclusions: Patients at higher risk of converting to SPMS have more severe global and focal cortical pathology at onset but also demonstrate a faster rate of cortical thinning. The extent of the early focal cortical damage affects the severity of grey matter loss in the long term, suggesting common mechanisms driving CLs and brain atrophy. Early relapse frequency and the extent of early focal cortical damage can be used for selecting groups at high risk of developing severe cortical atrophy, who may potentially benefit from early aggressive treatment.
Disclosure: Antonio Scalfari: nothing to disclose
Anna Isabella Pisani: nothing to disclose
Chiara Romualdi: nothing to disclose
Paolo Muraro: nothing to disclose
Richard Nicholas: nothing to disclose
Massimiliano Calabrese: nothing to disclose
Abstract: P490
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Brain atrophy occurs from the early phase of relapsing remitting (RR) MS and it is an important determinant of disease progression. We set out to explore factors affecting the rate of cortical thinning in the long-term.
Methods: Among 219 RRMS patients, followed from onset for 7.9 mean years, we used regression analysis to assess early factors affecting the rate of global cortical thickness (Cth) loss/year and predicting the most severe global cortical damage (worst 25Th percentile loss) over time.
Results: Within the observation period, 27% (59 of 219) of patients converted to secondary progressive (SP) MS, in 6.1 mean years; this subgroup had, at disease onset, significantly lower mean global Cth (SP=2.51 mm, RR=2.58 mm p=0.004) and higher number of cortical lesions (CLs) (SP=6.5, RR=1.8 mean lesions; p< 0.001), and displayed faster cortical thinning over time (SP=-1.31%/year, RR=-0.96%/year mean loss; p< 0.001). In the total population, at disease onset, a higher number of CLs was associated with a significantly lower mean global CTh (r = -0.188, p = 0.005). Factors associated with a larger proportion of grey matter loss/year were gender (male=-0.74%, female=-0.60%; p=0.03), number of CLs at onset (0 CLs=-0.56%, 1-3 lesions=-0.63%, 4-6 lesions=-0.73%, ≥7 lesions=-0.78%, p< 0.001) and number of relapses during the first two years (1 relapse=-0.47%, 2 relapses=-0.79%, ≥3 relapses=-0.94%; p< 0.001). The white matter lesions number at onset did not affect the rate of brain atrophy (lesions: ≤ 4=-0.68%, 5-8=-0.60%, 9-11=-0.67%, ≥12=-0.72%; p=0.13). In the multivariate model, a larger accumulation of CLs volume (OR=3.47; p=0.01), a more rapid cortical thinning during the first two years (OR=1.43; p=0.001), and ≥3 early relapses (OR=8.41; p< 0.001) independently predicted a higher risk of more severe global Cth loss at the end of the follow up.
Conclusions: Patients at higher risk of converting to SPMS have more severe global and focal cortical pathology at onset but also demonstrate a faster rate of cortical thinning. The extent of the early focal cortical damage affects the severity of grey matter loss in the long term, suggesting common mechanisms driving CLs and brain atrophy. Early relapse frequency and the extent of early focal cortical damage can be used for selecting groups at high risk of developing severe cortical atrophy, who may potentially benefit from early aggressive treatment.
Disclosure: Antonio Scalfari: nothing to disclose
Anna Isabella Pisani: nothing to disclose
Chiara Romualdi: nothing to disclose
Paolo Muraro: nothing to disclose
Richard Nicholas: nothing to disclose
Massimiliano Calabrese: nothing to disclose