LAUSR

A 29-year-old Chinese woman complained of recurring dizziness for 5 months and gait disturbance for 2 months. On admission (April 2016), she was found to have a widebased gait, horizontal nystagmus and positive heel-kneeshin test. Initial hematological, biochemical, microbiological, hormonal investigations and tumor serum markers were unremarkable. Oligoclonal bands were observed in cerebrospinal fluid (CSF) without other pathological changes, while magnetic resonance imaging (MRI) of cervical spine and brain were normal. An anterior mediastinal mass was noted by computed tomography (CT) [Figure 1A]. Despite a lack of paraneoplastic antibodies in CSF or serum, such as anti-neuronal nuclear autoantibody type 1 (ANNA-1, also known as “anti-Hu”), ANNA-2 (also known as “anti-Ri”), Purkinje cell antibody type 1 (PCA-1, also known as “anti-Yo”), anti-CV2 (also known as “collapsin response mediator protein 5 [CRMP5]”), anti-Ma, anti-Amphiphysin, anti-Tr (also known as “delta/notch-like epidermal growth factorrelated receptor [DNER]”) and anti-glutamic acid decarboxylase (GAD), her neurological manifestation still pointed toward one of the paraneoplastic neurological syndromes (PNSs).