Introduction

Paraneoplastic cerebellar syndrome is a rare immune-mediated disorder often associated with malignancies, most commonly gynecologic or breast cancers. This case explores a patient presenting with subacute cerebellar ataxia and positive anti-Yo antibodies, a marker of paraneoplastic neurological autoimmunity.

Clinical Presentation

A 62-year-old female presented with progressive dysarthria, gait instability, and limb incoordination over six weeks. Neurologic examination revealed nystagmus, scanning speech, and marked truncal ataxia. MRI of the brain showed diffuse cerebellar atrophy, and cerebrospinal fluid analysis demonstrated elevated protein and positive anti-Yo antibodies.

Diagnostic Workup

Given the strong association between anti-Yo antibodies and underlying malignancy, a comprehensive oncologic evaluation was initiated. Whole-body PET-CT revealed a hypermetabolic ovarian mass, and subsequent biopsy confirmed high-grade serous ovarian carcinoma. This linked the paraneoplastic cerebellar syndrome directly to the tumor.

Treatment and Outcome

The patient underwent tumor debulking and chemotherapy, combined with intravenous immunoglobulin and corticosteroids for immune modulation. Despite therapy, her cerebellar deficits only partially improved, highlighting the potential for irreversible Purkinje cell loss. Long-term follow-up emphasized neurologic rehabilitation and tumor surveillance.

Discussion

This case underscores the necessity of early detection of anti-Yo-associated paraneoplastic cerebellar syndrome. Prompt identification of the underlying malignancy is crucial, as neurologic disability can be progressive and often precedes cancer diagnosis. Multidisciplinary care remains essential for optimizing outcomes.

Keywords

Keywords: anti-Yo, paraneoplastic cerebellar syndrome, ovarian carcinoma, ataxia, Purkinje cells