Arteriovenous malformation

Spetzler-Martin Grade and Spetzler-Ponze Class
Developed in 1986, the Spetzler-Martin grading scale became commonly used as it correlates with perioperative morbidity. Several studies, including the initial one, have shown a correlation with surgical morbidity. The original Spetzler-Martin can be compression into a 3-tier system called Spetzler-Ponze Class.

Eloquent = cortex associated with sensorimotor, visual, or language functions; internal capsules; basal ganglia; thalamus; hypothalamus; brainstem; deep cerebellar nuclei; cerebellar peduncles

Deep venous drainage = any drainage via internal cerebral veins, basal veins, or precentral cerebellar vein

Spetzler-Ponze Class 3 is associated with worsened long-term health-related quality of life treatment, especially in the domains of vision and ability to do usual activities.

Supplementary Spetzler-Martin Scale / Lawton-Young Grade
In 2010, Lawton et al. developed a supplemental grading scale to incorporate additional factors, with better predictive value. This creates a combined score of possibly 10 points in total, correlating with outcome, and validated in a separate cohort.