Imaging: AV Malformation

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

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

7. Causes of intracranial hemorrhageCauses of intracranial hemorrhage
TraumaTrauma
SHTSHT
CoagulopathyCoagulopathy
DrugsDrugs
AVMAVM
TumorsTumors
aneurysmaneurysm

8. Investigations Investigations
Echo normalEcho normal
Coagulation profile normalCoagulation profile normal
Homocysteine level slight increaseHomocysteine level slight increase

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

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

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

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

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

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