Makindo Medical Notes

🧠 Foix-Alajouanine syndrome is a severe form of spinal dural AV fistula (AVF). It occurs in a minority of patients and presents with rapidly progressive myelopathy due to venous thrombosis from spinal venous stasis. ⚡

ℹ️ About

• Spinal AVMs (arteriovenous malformations) can cause acute, subacute, or chronic myelopathy.
• They often resemble AV fistulas, where high-pressure arterial blood enters the venous system, causing venous hypertension → spinal cord ischaemia and dysfunction.

⚠️ Aetiology & Classification

• Type 1: Dural AVMs (≈85%)
  • Most common form, usually in middle-aged men 👨.
  • Venous hypertension → expansion of lesion → spinal cord compression.
  • Affects corticospinal and posterior columns.
  • Management: Spinal angiography & obliteration of fistula.
• Type 2: Intradural AVMs (Glomus AVMs)
  • Arterial-pressure bleeding into subarachnoid space → myelopathy.
  • Seen in younger patients 👩‍🦱; fluctuating course with acute deterioration from haemorrhage.
• Type 3: Juvenile AVMs
  • Large, high-flow AVMs, sometimes with an audible bruit 🔊.
  • Clinical features resemble Type 2 but more extensive.
• Type 4: Perimedullary AV Fistulas
  • Rare; complex venous hypertension pattern.

🩺 Clinical Features

• Painful radiculopathy, especially in Type 1.
• Symptoms of spinal cord compression: gradual weakness, sensory loss.
• Bladder and bowel dysfunction 🚽 in advanced disease.
• Sudden haemorrhage → severe back pain + abrupt weakness.
• Intradural lesions may cause subarachnoid haemorrhage with excruciating back pain (“coup de poignard” — dagger-like pain) 🗡️.

🔬 Investigations

• MRI/MRA: First-line to identify AVMs and cord changes.
• Spinal arteriography: Gold standard for diagnosis and treatment planning 🎯.

💊 Management

• Endovascular therapy (interventional neuroradiology): Embolization of fistula or nidus using occlusive agents.
• Surgical removal: Considered for accessible lesions.
• Stereotactic radiosurgery: Causes gradual occlusion by scarring the AVM with focused radiation.