A 32-year-old man presents with a seizure. MRI reveals a 4 cm cerebral arteriovenous malformation (AVM) in the left frontal lobe, located in eloquent cortex, with deep venous drainage. According to the Spetzler-Martin grading system, what is the grade of this AVM?
- A Grade IV ✓
- B Grade III
- C Grade II
- D Grade V
Correct answer: A. Grade IV
Explanation
The Spetzler-Martin grade assigns points for size (<3 cm = 1, 3-6 cm = 2, >6 cm = 3), eloquent location (yes = 1, no = 0), and deep venous drainage (yes = 1, no = 0). This AVM scores 2 (size 3-6 cm) + 1 (eloquent) + 1 (deep drainage) = Grade IV. Grade V requires a score of 5 (size >6 cm plus both other features). This grading predicts surgical morbidity.
Reference: Bailey and Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.