title: Parieto-occipital arteriovenous malformation.
abstract: BACKGROUND
  Arteriovenous malformation (AVM) in the occipital lobe has been known to cause visual symptoms and headaches. Arteriovenous malformation is a congenital anomaly that consists of abnormal arteries and veins without the presence of a capillary bed. The majority of patients initially manifest intracranial hemorrhage, while others manifest symptoms of seizures, headaches, and progressive neurological deficits.
  
  
  METHODS
  A 45-year-old man was referred for a baseline threshold visual field before neurosurgery for his arteriovenous malformation. The patient's medical history included seizures with visual aura. The seizures were originally attributed to alcohol withdrawal; later, he was diagnosed with a right parietooccipital AVM. Optometric examination revealed an incomplete left inferior homonymous quadranopsia. He subsequently had the embolization and resection procedures for his AVM. Seizures and visual aura symptoms terminated after AVM surgery; the visual field defect increased slightly in extent. Two additional cases are presented to highlight some common characteristics-as well as the variability-in cerebral AVMs. The second case involves a 47-year-old man with a history of left frontal lobe AVM resection 7 years earlier and headaches. The third case is that of a 60-year-old man with a large left parietal lobe AVM with seizures who is anticipating neurosurgery.
  
  
  CONCLUSIONS
  Clinical differentiation of migraine from arteriovenous malformation is often regarded as difficult, since both conditions may manifest similar features of visual aura, with or without headaches. Early diagnosis and treatment of AVM may reduce the risk of serious complications. When a patient manifests alarming headaches with or without visual aura, neuro-imaging workup is warranted to rule out sinister causes.
mesh_terms: D002533:Cerebral Angiography; D003937:Diagnosis, Differential; D003941:Diagnostic Techniques, Ophthalmological; D004621:Embolization, Therapeutic; D006261:Headache / Q000209:etiology; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000098:blood supply*; D010296:Parietal Lobe / Q000098:blood supply*; D016634:Radiosurgery; D018570:Risk Assessment; D012640:Seizures / Q000209:etiology; D012684:Sensory Thresholds; D014786:Vision Disorders / Q000209:etiology*; D014794:Visual Fields; D014796:Visual Perception