four rural and urban communities. PLoS ONE 2012;7: e32638. 8. Chisholm D, Baltussen R, Evans DB, et al. What are the priorities for prevention and control of non-communicable diseases and injuries in sub-Saharan Africa and South East Asia? BMJ 2012;344:e586. SIMULTANEOUS PML-IRIS AFTER DISCONTINUATION OF NATALIZUMAB IN A PATIENT WITH MS Stella Marousi, Maria Travasarou, Clementine E. Karageorgiou, Athens, Greece: Gheuens et al. 1 pre- sented a case of progressive multifocal leukoencephalop- athy–immune reconstitution inflammatory syndrome (PML-IRIS) 2 months after natalizumab discontinua- tion. Their patient had an active history of ethanol abuse, which can be considered a ’ functional ’ equivalent to immunosuppression. Interestingly, prior use of immuno- suppressants has been included in the recently developed risk-stratification algorithm for PML. 2 This case under- scores the need for clinicians to adopt a wider concept of immunosuppression, rather than restricting it solely to the use of pharmacologic agents. We and others pub- lished 3 cases of definitive severe multiple sclerosis (MS) rebound about 2 months following natalizumab discon- tinuation, 3-5 and further implied that younger patients are more prone to such relapses. 5 However, Gheuens et al. concluded that new enhancing MRI lesions after natalizumab withdrawal may also be the manifestation of PML-IRIS. 1 As experience from patients discontinuing natalizumab and switching to other therapies mounts, a high degree of clinical vigilance for both incidences (i.e., MS rebound and PML) should follow the immediate post-natalizumab period. However, until official guide- lines are issued, it is unclear exactly how patients should be treated in the interval between natalizumab and the next therapeutic choice. Author response: Sarah Gheuens, Igor J. Koralnik, Boston: We thank Marousi et al. for their comments on our article. We agree that PML may also occur in the setting of occult or minimal immunosuppression, as seen in 5 cases at our center and in 33 previously reported patients. 6 As they mention, clinicians should be aware that either PML-IRIS or a relapse of MS may occur after discontinuation of natalizumab. © 2012 American Academy of Neurology 1. Gheuens S, Smith DR, Wang X, Alsop DC, Lenkinski RE, Koralnik IJ. Simultaneous PML-IRIS after discontinuation of natalizumab in a patient with MS. Neurology 2012;78: 1390–1393. 2. Bloomgren G, Richman S, Hotermans C, et al. Risk of natalizumab-associated progressive multifocal leukoenceph- alopathy. N Engl J Med 2012;366:1870–1880. 3. Lenhard T, Biller A, Mueller W, Metz I, Schonberger J, Wildemann B. Immune reconstitution inflammatory syndrome after withdrawal of natalizumab? Neurology 2010;75:831–833. 4. Hellwig K, Gold R. Immune reconstitution inflammatory syn- drome after withdrawal of natalizumab? Neurology 2011;76: 1362–1363; author reply 1363. 5. Marousi S, Giannouli E, Karkanis I, Tagaris GA, Karageorgiou CE. Immune reconstitution inflammatory syndrome after with- drawal of natalizumab? Neurology 2011;76:1362–1363; author reply 1363. 6. Gheuens S, Pierone G, Peeters P, Koralnik IJ. Progressive multifocal leukoencephalopathy in individuals with minimal or occult immunosuppression. J Neurol Neurosurg Psychiatry 2010;81:247–254. Author disclosures are available upon request (journal@neurology.org). 2160 Neurology 79 November 20, 2012 ª 2012 American Academy of Neurology. Unauthorized reproduction of this article is prohibited.