Summary

Cryptococcosis is a recognised opportunistic infection in immunocompromised patients. The long-term adverse effect profile of fingolimod, an immunomodulating agent approved for use in multiple sclerosis in 2010, is only just emerging. We report the first case to our knowledge of a patient presenting with obstructive hydrocephalus secondary to cryptococcal meningitis in the setting of fingolimod therapy. Extensive posterior fossa leptomeningeal inflammation with associated cerebellar oedema resulted in effacement of the fourth ventricle and obstructive hydrocephalus requiring urgent ventriculostomy. Induction, consolidative and maintenance antifungal therapy was prescribed and subsequent conversion to a ventriculoperitoneal shunt was successful in relieving the patient’s ventriculomegaly. Awareness of these rare, novel and life-threatening complications of fingolimod-associated immunocompromise is critical as the use of such drugs is expected to rise.