A case of suspected paraneoplastic nerve syndrome associated with prostate cancer or opsoclonus-myoclonus syndrome associated with COVID-19 infection, but symptoms improved after treatment of both.

INTRODUCTION

Paraneoplastic neurological syndrome is a type of neurological syndrome that occurs in patients with cancer; however, it is rarely associated with prostate cancer. We herein report a rare case of this condition.

CASE PRESENTATION: A 76-year-old man, treated conservatively for rotatory vertigo due to a subtype of Guillain-Barré syndrome after COVID-19, was referred to our neurology department. Magnetic resonance imaging showed no obvious findings; however, paraneoplastic neurological syndrome was suspected due to opsomyoclonus, and close examination of the primary tumor revealed a high prostate-specific antigen level and bone metastases, suggesting prostate cancer. Paraneoplastic nerve syndrome associated with prostate cancer was suspected. Since the possibility of OMS associated with COVID-19 infection was considered, bilateral orchiectomy and endocrine therapy, as well as pulse steroid therapy, were performed, and the patient's symptoms resolved.

CONCLUSION

This rare case suggests the need for timely and aggressive treatment for prostate cancer-associated paraneoplastic nerve syndrome.