1. Developmental Venous Anomaly: What are they really? W. Chong M. Holt H. Patel Interventional Neuroradiology Unit Monash Medical Centre Southern Health Melbourne, Australia

2. DVA Usually Asymptomatic Uncommonly -> Symptoms 1. Associated Lesions – Cavernomas -> Haemorrhage - Dysplasia -> Epilepsy 2. Mechanical Compression by DVA Compress Aqueduct -> Hydrocephalus V Nerve -> Trigeminal Neuralgia 3. Haemodynamic Imbalance – Inflow/Outflow Venous infarction / haemorrhage Thrombosis of DVA / Draining Vein Pereira. Stroke 39:3201-15, 2008 Ruiz. Ann of Neurol 66 (3):271-83, 2009

3. Aim Analyse 3 cases – Symptomatic and Asymptomatic With CT Perfusion (CBF, CBV, MTT, TTP) & 4D CTA Literature Review Propose possible Pathophysiological Mechanism for Symptomatic DVAs Propose a Classification

4. Materials and Methods 1. CT Methods: CTP - 320 Detector CT scanner (Toshiba Aquilon ONE) - 64 detector CT scanner (GE Lightspeed VCT XT) 4D CTA - 320 Detector CT scanner (Toshiba Aquilon ONE) 320 CT – Whole Brain CTP (16 cm coverage) - “4 Dimension” CTA -> Arterial & Venous Phases 2. MR - GE Signa Excite 1.5T & Siemens Magnetom Verio 3T 3. Cerebral angiogram - GE Advantx DLX Philips Allura FD 20/20 biplane units. 4. Correlate CBF, CBV, MTT, TTP and 4D CTA with Catheter DSA and Patient’s Symptoms

5. Results & Discussions Case 1 A 52 year old male - progressive right hemiparesis and dysdiadokinesia of the right upper and lower limbs Coarse irregular calcification subtle enhancement left Basal Ganglia region.

6. CBF Increased CBV Increased MTT Decreased

7. lenticulo-striate arteries early draining veins in arterial phase -> AV Shunting faint diffuse vascularity at the left basal ganglia.

8. Discussion Case 1: Increased CBF &CBV and Decreased MTT Central Volume Theory CBF = CBV / MTT “Deconvolution” Technique to derive the MTT and CBV CBF then solved by the the CV Theory Knowns: Circulatory Impairment -> Decreased CBF & Increased MTT Miles KA, Menon DK:, CT perfusion imaging, 2007 Venous Congestion -> Increased CBV & Increased MTT D. Lagares A. Neurosurgery 2010, doi:10.1227/01.NEU.0000361996.27921.6C Proliferative Angiopathy -> Increased CBV & Increased MTT Lasjaunias PL Stroke 39: 878-885, 2008

9. Increased CBF &CBV and Decreased MTT Decreased MTT -> Faster Passage of Contrast Bolus -> Reflects the AV shunting Increased CBV -> Number & Size of DVA vessels Increased CBF & Decreased MTT -> increased cerebral perfusion

10. Brain tissue hypoxia exists in a subset of patients with classical brain AVMs Moftakhar P. Neurosurg Focus 26 (5):E11, 2009 Steal phenomenon around AVMs -> chronic cerebral hypoperfusion -> local low flow anoxia in some AVMs Meyer B. Neurol Res 20 (Suppl 1): 13–7, 1998 ? Chronic venous Ischaemia in DVA -> Calcification Dehkharghani S. J. Neuroradiol 2010, doi:10.3174/ajnr.A2199.

11. Postulate: DVA with AV shunting behaves like an AVM -> resulting in an arterial steal -> local chronic hypoxia -> pathophysiological mechanism for the symptomatology -> calcification

12. Paradox: Increased CBF But have areas of hypoxia? CBF = Volume of Blood / 100 grams of brain tissue / per minute. It does not measure the oxygen uptake and usage by the neuronal cells. Normal: Cerebral blood flow and glucose metabolism is linked AV shunting -> Uncoupling of Link -> CBF ----X  Cell Metabolism

13. Case 2 49 year old male with a background of HIV and hepatitis C presented with chronic headaches Stippled Calcification Bilateral DVA - Right >> Left

14. Bilateral Early Draining Veins Prominent Lenticulo-Striates -> AV shunting – Similar to Case 1

15. Increased CBF Increased CBV Decreased MTT Decreased TTP

16. DVA in Case 2 = Case 1 DVA with AV Shunting Calcification ? Ischaemia related Why No Focal Symptoms related to the DVA Maybe Hypoxia not as severe as Case 1 Maybe Brain better compensated

17. Case 3 49 year old male who presented with palpitations and slurred speech. CT – DVA MR – DVA & Cavernoma (uncomplicated)

18. Typical DVA No Early Draining Veins No Venous Delay 4D CTA – Drainage in Normal Venous Phase No AV Shunting

19. Increased CBF Increased CBV Increased MTT Increased TTP

20. Case 3 Symptoms – Not Related to DVA All CTP Parameters Increased Camacho -> 4 asymptomatic DVAs - > All MRP Parameters Increased Hanson -> 5 asymptomatic DVAs - > All CTP Parameters Increased Camacho DLA. Am J Neuroradiol 25:1549–1552 Hanson EH. Neuroradiology 2010, doi:10.1007/s00234-010-0739-9

21. Increased MTT -> Slower Passage of Blood ? Abnormal Dilated Veins Retard Flow CBF = CBV / MTT Increased CBV -> Increased Number and Dilated Veins So the CBF simply reflect the above

22. Conclusion 1.Increased CBF and CBV and decreased MTT and TTP -> DVAs with micro AV shunting. AV Shunting -> Arterial Steal -> Chronic Hypoxia -> Symptomatic. But Some DVAs with AV Shunting are Not Symptomatic. Why? Increased CBF, CBV, MTT and TTP -> DVAs without shunting -> Typical Asymptomatic DVAs 4. Increased CBF, CBV, MTT and TTP can also -> DVA with evidence of venous congestion

23. DVA Usually Asymptomatic Uncommonly -> Symptoms 1. Associated Lesions – Cavernomas -> Haemorrhage - Dysplasia -> Epilepsy 2. Mechanical Compression by DVA Compress Aqueduct -> Hydorcephalus V Nerve -> Trigeminal Neuralgia 3. Haemodynamic Imbalance – Inflow/Outflow Venous infarction / haemorrhage Thrombosis of DVA / Draining Vein Pereira. Stroke 39:3201-15, 2008 Ruiz. Ann of Neurol 66 (3):271-83, 2009

24. Rodesch Classification: Asymptomatic (superficial and deep) DVAs, Asymptomatic DVAs with capillary stain, Symptomatic DVAs with capillary stain (acute or progressive symptoms) DVAs draining a true AV Shunt. Rodesch G et al. IX WFITN Congress in Beijing, 2007

25. Proposed Classification Asymptomatic DVA Superficial and Deep With capillary stain With AV shunting Symptomatic DVA With capillary stain With AV Shunting with venous thrombosis/venous congestion With AV Shunting with arterial steal With mechanical compression With associated lesions (cavernoma)

26. Thank You The “Bungles Bungles” Kimberley Western Australia