4.Vienna classification (**Table 4**).


#### **Table 1.**

*Spetzler-Martin grading scale for cAVM.*


#### **Table 2.**

*Supplementary Spetzler-Martin or Lawton-Young cAVM grading scale.*


*According to this grading system, there is 13% of hemorrhage in grade Ia, in grade Ib 38%, in grade II 48% and in grade III and IV risk of hemorrhage 90% [7].*

**Table 3.** *Nataf grading.*


**Table 4.**

*Vienna classification.*

#### **3.1 Luessenhop-Gennarelli grading**

This is the anatomical grading of supratentorial cAVM described in 1977, according to the degrees of surgical difficulty for total obliteration, graded into I–IV. Luessenhop-Gennarelli grading of cAVM is based upon the number of directly participating arteries for which there is a standardized nomenclature [4].

#### **3.2 Spetzler-Martin (S-M) grading**

In 1986 Spetzler and Martin graded cAVMs according to location, size and deep venous drainage, into the following five grades [5]:

1.Low-grade AVM: Grade I, grade II and grade III

2.High-grade AVM: Grade IV and grade V

3.Inoperable lesions: Grade VI (supplementary Spetzler-Martin (S-M Supp)).

The disadvantages of S-M grading of cAVM are definition of eloquence, lack of consideration for nidus compactness, not useful for posterior fossa AVM, only applicable for surgical outcome and grade III in homogeneity.

Supplementary Spetzler-Martin or Lawton-Young grading scale for cAVM was described in 2010, apart from the risk factors included in S-M grading; this S-M Supp grading system includes factors affecting the patient's outcome, namely, age, bleeding or compactness of the cAVMs (**Table 2**) [6]. Kim et al. from their cohort multicentre study concluded that S-M Supp grading system works better than the S-M grading for operability decisions and cut-off value for operability is S-M Supp scale of 6. S-M Supp also gives better post-operative neurological outcome predictability than the S-M score.

#### **3.3 Nataf grading**

In this 4-point grading, five angiographic parameters are used for the determinants of the bleeding risk.

#### **3.4 Vienna classification**

This classification is helpful in choosing the mode of treatment.

### **4. Morphology and type cAVM**

Depending on the type and morphology, cAVM (**Figure 2**) is divided into the following (**Tables 5** and **6**):

*Cerebral Arteriovenous Malformation from Classification to the Management DOI: http://dx.doi.org/10.5772/intechopen.86659*

#### **Figure 2.**

*Details of cAVM and associated aneurysms.*


#### **Table 5.**

*Morphology of cAVM.*


#### **Table 6.**

*Classification of aneurysm with cAVM [8].*
