BACKGROUND New inflammatory activity is of unclear frequency and clinical significance in progressive multiple sclerosis (MS); it is uncertain in patient cohorts with motor progression due to critical demyelinating lesions. OBJECTIVES The aim of this study is to determine the likelihood of central nervous system (CNS) inflammatory activity, assessed by new clinical relapses or active magnetic resonance imaging (MRI) lesions, following onset of motor progression due to critical demyelinating lesions. METHODS Patients with progressive upper motor neuron impairment for ⩾1 year attributable to critical demyelinating lesions with single CNS lesion (progressive solitary sclerosis (PSS)), 2 to 5 total CNS demyelinating lesions (progressive "pauci-sclerosis" (PPS)), or >5 CNS demyelinating lesions and progressive exclusively unilateral monoparesis or hemiparesis (PUHMS) were identified. Clinical data were reviewed for acute MS relapses, and subsequent MRI was reviewed for active T1-gadolinium-enhancing or T2-demyelinating lesions. RESULTS None of the 91 patients (22 PSS, 40 PPS, 29 PUHMS) identified experienced clinical relapses over a median clinical follow-up of 93 months (range: 12-518 months). Nine patients (10%) developed active lesions over median 84 months radiologic follow-up (range: 12-518 months). Active lesions occurred in 24% PUHMS, 5% PSS, and 3% PPS cohorts. CONCLUSION New inflammatory activity, defined by active lesions and clinical relapses following motor progression in patients with critical demyelinating lesions, is low. Disease-modifying therapies that reduce demyelinating relapses and active MRI lesions are of uncertain benefit in these cohorts.

中文翻译：

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由于严重的中枢神经系统脱髓鞘病变导致运动进展后的炎症活动

背景新的炎症活动在进行性多发性硬化症 (MS) 中的频率和临床意义尚不清楚；由于严重的脱髓鞘病变，在运动进展的患者队列中是不确定的。目的 本研究的目的是确定中枢神经系统 (CNS) 炎症活动的可能性，通过新的临床复发或活动性磁共振成像 (MRI) 病变评估，在由于严重脱髓鞘病变引起运动进展后。方法 因严重脱髓鞘病变伴单个 CNS 病变（进行性孤立性硬化症 (PSS)）、2 至 5 个总中枢神经系统脱髓鞘病变（进行性“稀少硬化症”（PPS））或> 确定了 5 个 CNS 脱髓鞘病变和进行性单侧单侧轻瘫或偏瘫 (PUHMS)。对急性 MS 复发的临床数据进行了审查，随后对活动性 T1 钆增强或 T2 脱髓鞘病变的 MRI 进行了审查。结果 在中位临床随访 93 个月（范围：12-518 个月）中，确定的 91 名患者（22 名 PSS、40 PPS、29 名 PUHMS）均未出现临床复发。在中位 84 个月的放射学随访（范围：12-518 个月）中，9 名患者 (10%) 出现了活动性病变。活动性病变发生在 24% 的 PUHMS、5% 的 PSS 和 3% 的 PPS 队列中。结论 严重脱髓鞘病变患者运动进展后的活动性病变和临床复发定义的新炎症活动较低。