1. A 41-year-old man presented with vomiting, altered mental status, and difficulty walking. On examination, he showed signs of brainstem involvement including nystagmus and facial weakness. 2. Imaging and lab tests did not reveal any coagulation abnormalities or structural causes like tumors. A slight elevation in homocysteine levels was found. 3. Cerebral angiography confirmed an arteriovenous malformation (AVM), which are congenital lesions caused by a failure of the embryonic vasculature to fully develop. The Spetzler-Martin grading system was then used to assess the AVM based on its size, location, and venous drainage patterns.

1. IMAGE OF THE WEEK PROF.DR.NOORUL AMEEN UNIT DR.M.JAGADEESAN I YR PG

2. 41 yr old saravanan was admitted with c/o vomiting 1 episode,altered sensorium and difficulty in walking since morning.no h/o of trauma Not a k/c DM ,SHT. Not a smoker/alcoholic o/e irritable nystagmus+,pooling of saliva+,9 th and 10 th N palsy,b/l plantar withdrawal BP-120/80mm Hg

7. Causes of intracranial hemorrhage Trauma SHT Coagulopathy Drugs AVM Tumors aneurysm

8. Investigations Echo normal Coagulation profile normal Homocysteine level slight increase

15. The Spetzler-Martin grading system helps predict the likelihood of satisfactory outcome if an attempt at surgical resection is made. The Spetzler-Martin grade is determined by adding the 3 individual scores from the table. High-grade AVMs are more difficult to resect, and, therefore, neurologic deficits from the surgery itself are more likely.

16. Size of AVM* Eloquence of adjacent brain† Pattern of venous drainage‡ Small (< 3 cm) 1 Noneloquent 0 Superficial only 0 Medium (3-6 cm) 2 Eloquent 1 Deep component 1 Large (>6 cm) 3

17. * Measure the largest diameter of the nidus of the lesion on angiography. † Eloquent areas include sensorimotor, language, visual, thalamus, hypothalamus, internal capsule, brain stem, cerebellar peduncles, and deep cerebellar nuclei. ‡ The lesion is considered superficial only if all drainage is via the cortical drainage system.

18. A V malformation Lesions of the cerebral vasculature develop such that blood flows directly from the arterial system to the venous system without passing through a capillary system. The arteriovenous (AV) shunt is the definitive characteristic of these lesions.

19. AVMs are considered congenital lesions and are characterized by a failure of the embryonic vascular plexus to fully differentiate and develop a mature capillary bed in the affected area Molecular biologic factors are thought to be important to AVM development. These may include vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Tissues adjacent to the AVM may be persistently mildly hypoxic because the malformation may steal blood from adjacent healthy tissue, further promoting angiogenesis.

20. Cerebral angiography provides definitive diagnosis. It documents a functional AV shunt; however, because it is an invasive test, it is not performed as the first imaging study. Cerebral angiography also allows grading of the AVM via the following Spetzler and Martin criteria.