This page was generated by AI. It is not a source of trustworthy medical information.
The curated page (written by a real person) is here

Case Presentation

Clinical Diagnosis

Paraneoplastic cerebellar degeneration (PCD) secondary to ovarian carcinoma, associated with anti-Yo antibodies.

Pathophysiology

Paraneoplastic cerebellar degeneration is a classic autoimmune neurologic syndrome. In this case, the patient's immune system generated antibodies (anti-Yo) against the tumor antigens expressed by the ovarian cancer cells. These antibodies cross-react with Purkinje cell cytoplasmic proteins (CDR2 and CDR2L) in the cerebellum, leading to rapid and irreversible Purkinje cell death. The cerebellum controls coordination and balance; its loss explains the severe ataxia and dysarthria. PCD is one of the most common paraneoplastic syndromes affecting the cerebellum, and anti-Yo is almost exclusively associated with gynecologic (ovarian, uterine, breast) malignancies.

Treatment and Outcome

• Oncologic treatment: Surgical cytoreduction (total abdominal hysterectomy with bilateral salpingo-oophorectomy) followed by carboplatin/paclitaxel chemotherapy.
• Immunomodulation: High-dose intravenous methylprednisolone (1 g/day for 5 days) initiated early, followed by oral prednisone taper.
• Plasmapheresis: 5 sessions performed due to lack of rapid response.
• IVIG: 2 g/kg monthly for 3 cycles.

Despite aggressive treatment, the patient's cerebellar deficits showed only marginal improvement. She remained wheelchair-dependent with severe dysarthria and required assistance for all activities of daily living at 6-month follow-up. Tumor was in remission after treatment. Neurologic disability was permanent.

Discussion

This case illustrates the hallmark features of paraneoplastic cerebellar degeneration:

• Subacute, bilateral, symmetric cerebellar syndrome (ataxia, nystagmus, dysarthria) evolving over weeks to months.
• MRI brain typically normal early; later shows cerebellar atrophy.
• CSF inflammatory changes (pleocytosis, elevated protein, oligoclonal bands).
• High-titer anti-Yo antibodies (very specific for gynecologic or breast cancers).
• Poor neurologic prognosis even with early tumor treatment and immunosuppression.
• Essential to search for occult malignancy — PCD often precedes cancer diagnosis.

Differential diagnoses include stroke, multiple sclerosis, infectious cerebellitis, Creutzfeldt-Jakob disease, and drug-induced ataxia. The presence of anti-Yo antibodies narrows the cause to paraneoplastic cerebellar degeneration.

Key Learning Points

• Consider PCD in any patient with subacute progressive ataxia, especially women with history of breast/ovarian cancer.
• Anti-Yo (PCA-1) antibody testing is diagnostic; it has >99% specificity for PCD.
• MRI may be normal but does not rule out the condition.
• Aggressive tumor treatment may stabilize but typically does not reverse severe cerebellar injury.
• Early immunosuppression (steroids, IVIG, plasmapheresis) may yield better outcomes if started within days of symptom onset — less than 20% of patients regain independent ambulation.