PT - JOURNAL ARTICLE AU - Abdul Badran AU - Carla Moran AU - Alasdair J Coles TI - Hypothyroid ataxia complicating monoclonal antibody therapy AID - 10.1136/practneurol-2017-001713 DP - 2017 Oct 21 TA - Practical Neurology PG - practneurol-2017-001713 4099 - http://pn.bmj.com/content/early/2017/10/21/practneurol-2017-001713.short 4100 - http://pn.bmj.com/content/early/2017/10/21/practneurol-2017-001713.full AB - We present a case of cerebellar dysfunction due to severe hypothyroidism induced by pembrolizumab, a member of the ‘immune checkpoint inhibitor’ class of cancer immunotherapies. Thyroxine replacement completely resolved his symptoms and signs. We also discuss the neurological immune-related complications of checkpoint inhibitors.