title: Anti-collapsin response mediator protein 5 encephalitis masquerading as a low-grade brain tumour.
abstract: A 71-year-old woman presented acutely with seizures; her MRI suggested a low-grade glioma of the right temporal lobe. Over the preceding 18 months, she had developed progressive limb chorea and orofacial dyskinesia. Examination showed a predominantly amnestic cognitive profile. Initial investigations were normal, but later she was found to have antibodies to collapsin response mediator protein 5 (also called CV2). Her symptoms and neuroimaging abnormalities gradually improved without treatment. Four months later, surveillance imaging with (18)F-fluorodeoxyglucose-positron-emission tomography revealed a lesion confirmed by biopsy as a TX, N2, M0 small-cell lung cancer. This case is unusual for the strikingly unilateral neuroimaging abnormalities, which led to an initial misdiagnosis, and the spontaneous symptomatic improvement without treatment. In retrospect, the co-occurrence of paraneoplastic chorea, limbic encephalitis and neuropathy in the presence of an occult lung tumour make this almost a 'full house' of symptoms associated with antibodies to collapsin response mediator protein 5. It underlines the importance in clinical reasoning of avoiding the cognitive errors of premature closure and anchoring.
authors.affiliation: Department of Clinical Neuroscience, University of Cambridge, Herchel Smith Building for Brain and Mind Sciences, Forvie Site, Robinson Way, Cambridge Biomedical Campus, Cambridge, UK Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Cope
authors.affiliation: Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: David P
authors.initials: DP
authors.lastname: Breen
authors.affiliation: Barking Havering and Redbridge University Hospitals NHS Trust, Queen's Hospital, Romford, Essex, UK.
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Chawda
authors.affiliation: Barking Havering and Redbridge University Hospitals NHS Trust, Queen's Hospital, Romford, Essex, UK.
authors.forename: Alberto
authors.initials: A
authors.lastname: Cifelli
mesh_terms: D000368:Aged; D001921:Brain; D001932:Brain Neoplasms / Q000175:diagnosis*; D004660:Encephalitis; D005260:Female; D006801:Humans; D006867:Hydrolases; D020363:Limbic Encephalitis / Q000175:diagnosis*; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D040121:Semaphorin-3A
chemical_list: D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D040121:Semaphorin-3A; C415087:DPYSL5 protein, human; D006867:Hydrolases
keywords: NEUROIMMUNOLOGY; PARANEOPLASTIC SYNDROME