Makindo Medical Notes

Related Subjects: |Subarachnoid Haemorrhage |Haemorrhagic stroke

🧠 Introduction

• Cerebral cavernous malformations (CCMs) are the most common vascular malformations of the CNS.
• They are clusters of abnormal, thin-walled blood vessels that may bleed, sometimes extending beyond their fragile walls.
• Prevalence: ~0.1–0.5% of the population; some have a genetic basis.
• More common in Hispanic communities, especially Mexican-Americans.

🔬 Pathophysiology

• CCMs lack large feeding arteries or draining veins (“angiographically occult”).
• Can occur anywhere in the brain or spinal cord; deeper lesions (e.g. brainstem) bleed more often than superficial ones.
• Genetic variants:
  • CCM1 → chromosome 7q.
  • CCM2 → chromosome 7p.
  • CCM3 → chromosome 3p (often more severe, early onset).

🩺 Clinical Presentation

• Many are asymptomatic, found incidentally on MRI.
• When symptomatic → intracerebral haemorrhage, seizures, focal deficits, raised ICP, headaches, or hydrocephalus.

📍 Cavernomas in the Midbrain

Brainstem cavernomas are particularly high risk due to eloquent location and frequent haemorrhage-related morbidity.

🧾 Investigations

• CT/MRI: Characteristic “raspberry” or “popcorn-like” appearance, with or without haemorrhage.
• MRI SWI/GRE: Best for detecting blood products (haemosiderin). Highly sensitive.
• Angiography: Typically negative (lesions are angiographically occult).

📊 MRI Types (Zabramski classification)

• 🟥 Type I: Subacute haemorrhage → hyperintense core on T1/T2.
• 🟧 Type II: “Popcorn” lesion → mixed signals on T1/T2 with hypointense rim.
• 🟨 Type III: Chronic/resolved haemorrhage → isointense core, often familial.
• 🟩 Type IV: Tiny foci, only visible on GRE/SWI, may mimic capillary telangiectasias.

⚖️ Management

• Options: Conservative, microsurgical resection, or stereotactic radiosurgery.
• Surgery indicated: Recurrent haemorrhage, intractable seizures, or progressive neurological deficit (esp. non-eloquent regions).
• Brainstem cavernomas → controversial but some evidence supports resection due to high morbidity if left untreated.
• Conservative management: Annual MRI follow-up if asymptomatic or low-risk.

📖 References

• Mouchtouris N. et al., Management of Cerebral Cavernous Malformations: From Diagnosis to Treatment

💡 Exam Pearl: Cavernomas are angiographically occult. Think “popcorn lesion” on MRI → consider cavernoma.