Makindo Medical Notes

🧠 Paraneoplastic Cerebellar Degeneration (PCD) is a rare, immune-mediated neurological syndrome linked to underlying cancers. ⚠️ Cerebellar symptoms may appear before the cancer is diagnosed, so recognising PCD early is crucial. Unlike metastases, this is not due to tumour spread but to an autoimmune response against cerebellar neurons.

📌 Associated Cancers

• 🎀 Gynaecological cancers: ovarian, uterine, adnexal
• 🎗️ Breast cancer
• 🚬 Small-cell lung carcinoma
• 🧬 Hodgkin lymphoma

🧬 Aetiology

• Loss of Purkinje cells → cerebellar atrophy and dysfunction.
• Immune-mediated: antibodies cross-react with tumour and neuronal antigens.
• Not caused by direct metastasis but by paraneoplastic autoimmunity.

🩺 Clinical Features

• ⏱️ Rapid onset, progressing over weeks–months.
• 🎢 Early: dizziness, nausea → progressing to vertigo and nystagmus.
• Ataxia: Limb + truncal instability, unsteady gait 🚶.
• Dysarthria: Slurred speech, may progress to dysphagia.
• 🤲 Fine tremor of hands or head in some cases.

🔬 Investigations

• Antineuronal Antibodies (positive in ~50% cases):
  • Anti-Yo → breast/ovarian cancers
  • Anti-Tr → Hodgkin lymphoma
  • Anti-Hu → small-cell lung cancer
• MRI Brain: May be normal early; later shows cerebellar atrophy.
• CSF: Mild pleocytosis, ↑ protein, Purkinje cell antibodies possible.
• Tumour screening: CT, PET, mammography, or pelvic imaging to search for occult malignancy.

💊 Management

• 🎯 Tumour treatment: Detect and treat underlying malignancy early — improves prognosis.
• 🛡️ Immunotherapy: Corticosteroids, IVIG, or plasma exchange — variable response.
• 💉 Chemotherapy/targeted therapy: May stabilise some cases, but neuro deficits often persist.
• 🤝 Supportive care: Physiotherapy, occupational therapy, speech therapy for balance, mobility, and communication.

📉 Prognosis

• Often poor: many patients develop permanent disability.
• Best outcomes when tumour is detected and treated early.
• Neurological recovery is limited even with immunosuppression.

📚 References

• Graus F, et al. Paraneoplastic neurological syndromes: clinical and immunological features. Lancet Neurol. 2004.
• Darnell RB, Posner JB. Paraneoplastic syndromes involving the nervous system. N Engl J Med. 2003.