Foix-Alajouanine syndrome is an extreme form of spinal dural AVF that affects a minority of patients. These patients present with rapidly progressive myelopathy due to venous thrombosis from spinal venous stasis.
About
- Spinal AVMs can cause acute, subacute, or chronic myelopathy.
- Often resemble AV fistulas, with high-pressure flow into the venous system, leading to venous hypertension.
Aetiology
- Type 1: Dural AVMs (85%)
- Most common type; causes venous hypertension and bleeding.
- Venous hypertension expands the lesion, increasing pressure on the spinal cord and reducing blood flow.
- Affects corticospinal and posterior columns; middle-aged men most commonly affected.
- Management: Spinal angiography and obliteration of the AVM.
- Type 2: Intradural AVMs or Glomus AVM
- Can bleed at arterial pressure into the subarachnoid space, leading to myelopathy.
- Common in younger patients; characterized by fluctuating myelopathy with periods of acute deterioration due to hemorrhage within the AVM.
- Type 3: Juvenile AVM
- High-flow and high-pressure AVM, sometimes with an audible bruit.
- Clinical presentation similar to Type 2.
- Type 4: Perimedullary Arteriovenous Fistula
- Rare type of spinal AVM; presents with complex venous hypertension.
Clinical Features
- Painful radiculopathy, often associated with Type 1 AVMs.
- Symptoms of spinal cord compression, including gradual onset of weakness and sensory impairment.
- Bladder and bowel disturbances in advanced cases.
- Sudden haemorrhage may cause intense back pain and sudden weakness.
- Intradural lesions may present with subarachnoid haemorrhage, known as coup de poignard, due to excruciating back pain.
Investigations
- MRI/MRA of the brain and spinal cord to assess for AVM presence and structure.
- Arteriography : The standard imaging modality for visualizing arteriovenous malformations.
Management
- Surgical removal may be considered for accessible AVMs.
- Stereotactic radiosurgery : Used to scar the AVM, promoting clot formation and occlusion.
- Interventional neuroradiology/endovascular neurosurgery : Endovascular procedures can be used to insert an occlusive device within the AVM.