Introduction

Antibodies that target the extracellular domain of neuronal cell-surface proteins and thus are likely to contribute directly to the pathology of the condition. Patients with these antibodies often do not have associated tumours and tend to respond well to immunotherapies, with tumour treatment, if appropriate. Successful treatments are often associated with paralleled reductions in antibody concentrations. Some appear to have a monophasic course but others may relapse and require ongoing immunosuppression.1

By contrast, onconeural antibodies usually target intracellular proteins and represent markers of an associated cancer but have not, in general, been shown to be pathogenic.2 Patients with these onconeural antibodies usually do not respond to immunosuppression even in addition to tumour removal. Nevertheless, because of the importance of identifying an underlying neoplasm, onconeural antibodies are often also requested when an autoimmune condition is suspected, even when a cell-surface neuronal autoantibody is found.

Although all currently recognised antibody-mediated non-paraneoplastic central nervous system (CNS) disorders are rare, numbering perhaps 5–10 per million per year (based on current results of routine antibody screening from the Oxford Clinical Service), it is important to identify these disorders so that appropriate treatments can be offered. Here, we describe the …