Anti-SOX-1 Antibody-Positive Paraneoplastic Limbic Encephalitis Diagnosed During Small Cell Lung Cancer Treatment

We present a case of anti-Sry-like high mobility group box 1 (SOX-1) antibody-positive PNS diagnosed during the treatment of small-cell lung cancer (SCLC). A 65-year-old woman with a history of smoking and SCLC (T3N1M0) was hospitalized to receive chemo-radiation therapy. On day 14, the course was complicated by left mastitis associated with febrile neutropenia. Drainage was performed for the left mastitis, and cefepime was initiated. The fever subsided within a few days, but the patient became agitated accompanied by logorrhea. With the exception of mental status, her neurological examination was unremarkable. Due to mildly impaired renal function, cefepime encephalopathy was considered in the differential diagnosis, but the agitation grew worse despite cefepime discontinuation. Further evaluations, including brain magnetic resonance imaging without contrast and cerebrospinal fluid analysis, were unremarkable. Acyclovir and steroid pulse therapy were initiated empirically for herpes simplex virus (HSV) and PNS, respectively. On day 22, acyclovir was discontinued because the HSV polymerase chain reaction test result was negative. On day 26, the serum anti-SOX-1 antibody test was reported to be positive. Other paraneoplastic syndrome-associated antibodies, including anti-amphiphysin, CV2, PNMA2, Ri, Yo, Hu, recoverin, titin, zic 4, GAD 65, Tr, and N-methyl-D-aspartate receptor antibodies, were negative. The agitation improved gradually following the continuation of chemotherap...
Source: Herpes - Category: Infectious Diseases Authors: Source Type: research