AVM and Epilepsy: Seizure Types, Localization, and Sturge-Weber Syndrome

Arteriovenous malformations (AVMs) are tangled vessels bypassing capillaries. They can cause epilepsy via hemorrhage, mass effect, or chronic hypoperfusion (steal phenomenon). Seizure type depends on AVM location.

Focal Seizures (Most Common)

• Temporal lobe AVM: Most frequent. Seizures: staring, automatisms (lip smacking, fumbling), impaired awareness, déjà vu, olfactory/gustatory auras.
• Frontal lobe AVM: Brief, stereotyped motor seizures (tonic/clonic posturing, bicycling), often nocturnal, with preserved awareness initially. May have vocalizations, laughter, or fear.
• Parietal/occipital AVM: Sensory (tingling, numbness) or visual (flashes, blindness) auras.

Generalized Seizures

• Tonic-clonic (grand mal): Loss of consciousness, stiffening, jerking, postictal confusion. Can be primary generalized or focal-to-bilateral tonic-clonic.
• Absence (petit mal): Brief staring, eyelid fluttering, 5-10 seconds, no postictal state. Rarely from AVM; more typical of genetic generalized epilepsy.

Sturge-Weber Syndrome

Not caused by AVM but by capillary venous malformation (port-wine stain in V1 trigeminal distribution) with leptomeningeal angioma. Presents in infancy with:

• Focal seizures (often refractory)
• Hemiparesis, intellectual disability
• Glaucoma (choroidal hemangioma)
• Progressive neurological deterioration

Management

Antiseizure medications tailored to seizure type. AVM treatment (embolization, radiosurgery, resection) may reduce seizure burden. Multidisciplinary team (neurology, neurosurgery, neuroradiology) essential.