TY - JOUR T1 - Midbrain encephalitis associated with neoplasia JF - Practical Neurology JO - Pract Neurol SP - 178 LP - 180 DO - 10.1136/practneurol-2012-000395 VL - 13 IS - 3 AU - Arani Nitkunan AU - Michael P T Lunn AU - Gordon T Plant AU - Fred Schon Y1 - 2013/06/01 UR - http://pn.bmj.com/content/13/3/178.abstract N2 - Limbic encephalitis typically presents with memory impairment, seizures and psychiatric disturbances. Even 10 years ago, autoimmune limbic encephalitis was considered almost always paraneoplastic but many other causes are now recognised, including autoimmune processes independent of a malignancy.1 In a recent series, clinical brainstem involvement (ataxia, dizziness, diplopia) occurred in 13 of 50 paraneoplastic limbic encephalitis cases, with hypothalamic involvement in 11 of 50.2 Parinaud's syndrome has not been reported as a feature of paraneoplastic limbic encephalitis. Parinaud's syndrome, first described in 1886,3 involves a combination of eye signs—most commonly, limitation of up and down gaze, failure of convergence, dissociation of lid and eye movements (ptosis, lid retraction) and convergence–retraction nystagmus. Reported underlying lesions usually localise to the dorsal midbrain. The most common causes are pinealomas, stroke and multiple sclerosis. There have been no reported immunological causes. We describe an extremely challenging case associated with an underlying neoplasm. A 52-year-old male professional opera singer had been well apart from coronary artery stenting following myocardial infarction. He presented in October 2010 with ‘difficulty focusing’ while walking in the New Forest in the UK, finding it difficult to change from looking at the horizon down on to a map. Walking through a crowd felt draining, as was making out facial detail while walking. He had to feel his way around a plate of food as he could not look down at it and could not check if he … ER -