The Spetzler Martin Grading Scale estimates the risk of open neurosurgery for a patient with AVM, by evaluating AVM size, pattern of venous drainage, and eloquence of brain location. A Grade 1 AVM would be considered as small, superficial, and located in non-eloquent brain, and low risk for surgery. Grade 4 or 5 AVM are large, deep, and adjacent to eloquent brain. Grade 6 AVM is considered not operable.

Note however, that this scale does not necessarily correlate with risk of treatment by embolization or radiosurgery.

## Spetzler Martin Grading Scale

![](/sites/default/files/Patient_Care/Specialty_Care/Stroke_and_Cerebrovascular_Center/Services/Arteriovenous_Malformations__AVMs_/Spetzler_Martin_Grading_Scale/field_Attachments/spetzlerMartin-GradingScale.jpg)

### Size of AVM

Small (< 3 cm) 1  
Medium (3-6 cm) 2  
Large (> 6 cm) 3

### Location

Noneloquent site 0  
Eloquent site\* 1

### Venouse drainage

Superficial 0  
Deep 1

\*Sensorimotor, language, visual cortex, hypothalamus, thalamus, brain stem, cerebellar nuclei, or regions directly adjacent to these structures.

## References

- Spetzler RF, Martin NA. [A proposed grading system for arteriovenous malformations](http://www.ncbi.nlm.nih.gov/pubmed/3760956?). J Neurosurg 1986;65:476-83.
- Iancu-Gontard D, Weill A, Guilbert F, Nguyen T, Raymond J, Roy D. [Inter- and intraobserver variability in the assessment of brain arteriovenous malformation angioarchitecture and endovascular treatment results.](http://www.ajnr.org/cgi/content/full/28/3/524) Am J Neuroradiol 2007;28(3):524-7.