PT - JOURNAL ARTICLE AU - Rémy Phan-Ba AU - Emilie Lommers AU - Luaba Tshibanda AU - Philippe Calay AU - Bernard Dubois AU - Gustave Moonen AU - David Clifford AU - Shibeshih Belachew TI - MRI preclinical detection and asymptomatic course of a progressive multifocal leucoencephalopathy (PML) under natalizumab therapy AID - 10.1136/jnnp-2011-300511 DP - 2012 Feb 01 TA - Journal of Neurology, Neurosurgery & Psychiatry PG - 224--226 VI - 83 IP - 2 4099 - http://jnnp.bmj.com/content/83/2/224.short 4100 - http://jnnp.bmj.com/content/83/2/224.full SO - J Neurol Neurosurg Psychiatry2012 Feb 01; 83 AB - Early detection of progressive multifocal leucoencephalopathy (PML) in the setting of natalizumab therapy currently is performed by rapid evaluation of new symptoms occurring in treated patients. The role of MR scanning has not been investigated but holds promise since MR detection is highly sensitive for PML lesions. The authors report a case of presymptomatic PML of the posterior fossa detected by MR scans. Immediate suspension of natalizumab and plasma exchanges resulted in a rapid decline of natalizumab serum concentration. Intravenous steroids started together with plasma exchanges followed by an oral tapering course were used to minimise the immune reconstitution inflammatory syndrome. No symptoms (beyond mild headache) developed, and the repeat PCR for JC Virus (JCV) DNA detection performed 10 weeks later was negative. This case suggests that: (1) periodic brain MR scans may detect signs of presymptomatic PML in MS patients treated with natalizumab, (2) corticosteroid management of inflammatory reaction may contribute to optimal control of the immune reconstitution inflammatory syndrome routinely seen with natalizumab-associated PML and (3) early radiological detection of PML can have an excellent outcome even in a clinically critical region and despite prior immunosuppressant exposure. The potential benefit of regular MR scanning just using the T2/FLAIR modalities could be further investigated in order to detect early natalizumab-associated PML, leading to benign outcomes.