Chapter 57D. Arteriovenous Malformations Flashcards
Question 57D-1: Which of the following imaging modalities is best able to identify and characterize a cavernous malfonnation? A. Angiography B. CT C. MRJ D. PET
Answer 57D-l: C. MRI is best able to identify and characterize a cavernous malformation. These types of malformations can be seen on CT, but the MRl shows a more characteristic appearance. Cavernous malformations are often invisible on angiography. (p1287)
Question 57D-2: Which of the following are potential presentations of arteriovenous malformations? 1. Seizures 2. Headaches 3. Hemorrhage 4. Infarction Select: A= 1,2,3. B = 1,3. C = 2,4. D = 4 only. E= All
Answer 57D-2: E. All of these are potential complications of AVMs, although infarction is the least likely of these. Ischemia is related to steal phenomenon, with shunting of blood from neural tissues. (p 1288)
Question 57D-3: A patient with partial seizures. with secondary generalization is found to have a cavernous malfonnation. There is no sign of past or recent bleeding. Which is the best approach to therapy? A. Surgical excision B. Stereotactic radiosurgery C. Medical therapy of the seizures
Answer 57D-3: C. - Surgery is often not necessary if there is no sign of hemorrhage. Patients with seizures may be controlled with AEDs alone. If the seizures are refractory to AED therapy, then surgical resection can be attempted. The exact role of stereotactic radiosurgery is still not established, but this may be a good option for patients needing surgery but with a location with difficult access. (p1294)
Question 57D-4: Decisions as to whether to operate on an AVM are often complex. Which of the following features would tend to argue in favor of surgery? 1. Small lesion 2. Accessible location 3. Sign of previous hemorrhage 4. Deep venous drainage Select: A = 1,2,3. B = 1,3. C = 2, 4. D = 4 only. E = All
Answer 5704: A. Deep venous drainage makes the risk of surgery somewhat increased, although this is just one of a number of factors. A small lesion in an accessible location which has bled in the past would be ideal for resection. Each decision is individualized. (P1294)
Question 57D-5: The image shown is a Tl-weighted sagittal MRI What is the most likely diagnosis? A. AVM B. Cavernous angioma C. Capillary telangiectasia D. Venous angioma
Answer 570-5: B. The arrow is pointing to a typical cavernous angioma. The areas of high signal are small hemorrhages. Note the rim of decreased density. This MRI appearance is characteristic. (p12877)
