Vascular Neurology Flashcards
What feature of AICA infarct will not be seen in PICA infarct?
Hearing loss (unclear whether this is due to effect on lateral pontomedullary tegmentum or the inner ear itself (via labyrinthine artery off AICA)
What single arterial lesion can cause bilateral thalamic strokes?
Artery of Percheron (anatomic variant, arises from P1 and supplies both medial thalami).
Supply to anterior and posterior limbs of internal capsule:
Anterior: ACA deep penetrating vessels (including recurrent artery of Huebner) (These also supply inferior caudata head and anterior globus pallidus)
Posterior: MCA lenticulostriate branches (these also supply putamen, part of caudate head/body, outer globus pallidus, and corona radiata) + Anterior choroidal artery
What is supply of thalamus (in broad terms)?
Branches of PCA and Pcomm
Four major arteries supplying the thalamus
- Tuberothalamic (off Pcomm): Anterior thalamus (especially ventral anterior nucleus)
- Thalamoperforating/paramedian artery (off P1): Medial thalamus (especially dorsomedial nucleus)
- Thalamogeniculate artery (off P2): Lateral thalamus (including ventral lateral nuclei)
- Posterior choroidal artery (off P2): Posterior thalamus (including pulvinar ucleus)
Anterior choroidal artery: Origin and structures supplied
Origin: ICA just above Pcomm origin
Supplies: GPi, part of posterior limb of internal capsule, part of geniculocalcarine track. Part of choroidal plexus (posterior choroidal artery from posterior circulation does the rest).
Medial medullary syndrome
- Contralateral limb weakness (pyramic)
- Contralateral proprioception/vibration loss (medial lemniscus)
- Ipsilateral tongue weakness (hypglossal fibers)
What lesion causes alexia without agraphia?
L occipital infarct with involvement of splenium of corpus callosum
( R visual cortex information cannot cross to L language centers)
Deficits in ventral mesencephalic tegmentum
- Ipsilateral CN III palsy (fascicle of CN III)
- Contralateral involuntary movements (tremor and choreoathetosis) (supserior cerebellar peduncle, also ventral red nucleus)
(May also have contralateral weakness)
(Called Benedikt’s syndrome)
Parinaud’s syndrome: localization and deficits
Localization: Dorsal midbrain / tegmentum / quadrigeminal plate (inferior and superior colliculi)
Syndrome:
- Supranuclear vertical gaze palsy
- Impaired convergence
- Convergence-retraction nystagmus
- Light-near dissociation
- Lid retraction
- Skew deviation
Branches from 4 ICA segments
- Cervical: no branches
- Petrous: Vidian and caroticotympanic branches
- Cavernous: meningohypophyseal trunk, inferolateral trunk, capsular arteries
- Supraclinoid: Ophthalmic, superior hypophyseal, Pcomm, anterior choroidal
(Then branches into MCA and ACA)
“Popcorn” appearance on MRI.
How does it present?
Cavernous malformation
Usually incidental. Can be seizures, rarely hemorrhage
Unusual or irregular arrangement of small veins that may look like the spokes of a wheel
How does it present?
DVA
Asymptomatic. Risk of hemorrhage very low
Vascular malformation that can present with signs of elevated ICP
Dural AVF
3 most common locations for saccular aneurysm?
- Acomm (30%)
- Pcomm (25%)
- MCA bifurcation (20%).
Less common: ICA bifurcation (7.5%0, basilar apex (7%), pericallosal artery (4%), PICA origin (3%).