Blood Supply of the Brain

1. Internal carotid arterya. Opthalmic a. b. Anterior choroidal a.

i. Optic tractii. Choroid plexus of inferior lateral ventricle

iii. Ventromedial temporal lobeiv. Globus pallidusv. Thalamus

vi. Ventral internal capsule**AntChA Occ:

- Contra hemiparesis, contraHemianesthesia, hemianalgesiaContra homonomous hemi

c. Posterior communicating a. i. Anastomoses with PCA

d. Anterior cerebral a. i. Anteromedial basal ganglia

ii. Internal capsuleiii. Superior corpus callosumiv. Anterior ¾ of medial cerebral hemispherev. Medial striate aa.

**ACA Occlusion:- Contra paresis of LE w/ UMN signs, contra anesthesia of LE, pure

disorder of speech initiation (SMA), conj. eye deviation to side of lesion (FEF), transcortical motor aphasia, anterior disconnection syndrome (alien hand syndrome!), frontal release signs,

**Looks a lot like other occlusions, however it presents with amaurosis fugax (MCA does not).

- AKA: Transient monocular blindness (ophthalmic a. loss to retina and optic n.) fog/haze/curtain, sudden, brief (1-30min), painless vision loss.

e. MIDDLE CEREBRAL A . i. Lateral cerebral hemisphere (frontal, parietal, temporal, occipital)

ii. Primary motor and somatosensory areasiii. Premotor cortexiv. FEFs v. Primary auditory cortex

vi. Broca’s and Wernicke’s areasvii. Associational areas of parietal cortexviii. Optic radiations

ix. Lenticulostriate aa. 1. Deep diencephalon and telencephalon2. Striatum3. Anterior/posterior limbs of internal capsule**Occluded lenticulostriate: pure motor syndrome

Contra hemiparesis: lower face, arm and leg equally effected (CST in PL of IC)

UMN signs: general paresis, inc. tone with spasticity, brisk clonus, inc. DTR, + Babinski

Spasticity (due to frontal lobe or CST), velocity dependent (clasped knife is seen)

**M1 (stem) Occlusion:- Contralateral hemiparesis, conjugate eye deviation to side of lesion

(lose FEF), contra hemianalgesia and hemianesthesia, contra homonymous hemianopsia, global aphasia (if dom. Hemi involved), contra hemineglect if non-dom involved…. LOSE i-viii

**Superior trunk occlusion:- Precentral a, Central a, and Postcentral a- Contralateral paresis (lower face and arm)-Central, contra anes/analg

of face and arm (Postcentral), conj eye deviation to side of lesion (Precentral)

- In dom hemi: Broca’s aphasia, in Non-dom hemi: Motor aprosodia (Precentral a)

**Inferior trunk occlusion:- In dom hemi: Wernicke’s aphasia, in Non-dom hemi: sensory

aprosodia- In either hemi: can get a contra homonymous hemi or contra inferior

quadrantanopsia2. Vertebral a.

a. Posterior inferior cerebellar a. (PICA) i. Posterior and inferior cerebellum

ii. Choroid plexus of 4th ventricleiii. Dorsolateral medulla

**PICA lesion: Vertigo (nodulus involvement), Headache (unilat are ipsi to lesion), gait and limb ataxia (often fall toward side of lesion), nystagmus,

b. Posterior spinal a. i. Dorsal horns and posterior funiculi

**PSA: ipsi loss of proprioception and vibration sense below the lesion, and ipsi loss of tendon and cutaneous reflexes for the affected segment

c. Anterior spinal a. i. Anterior 2/3 of spinal cord (ventral median fissure)

**ASA: Sudden onset of radicular or diffuse neck pain followed by quadriparesis, analgesia and thermoanesthesia 1-2 segments below the lesion, see LMN in UE, UMN in LE

d. Basilar a. i. Anterior inferior cerebellar a. (AICA)

1. Lateral caudal pons2. Anterior/inferior cerebellum (flocculus, MCP) **AICA: vertigo, nausea, vomiting, nystagmus, ipsi facial plegia, ipsi anacusis &/or tinnitus, ipsi trigeminal sensory loss, ispi Horner’s syndrome, ipsi limb ataxia/dysmetria, contra limb and trunk hemianalgesia/thermoanesthesia (STT)

ii. Labyrinthine (internal acoustic) a. 1. Runs through internal acoustic meatus to supply inner ear2. Can cause vertigo or ipsilateral deafness

iii. Pontine aa. iv. Superior cerebellar a. (SCA)

1. Lateral rostral pons2. Caudal midbrain

3. Superior cerebellum (vermis, deep cerebellar nuclei, cerebellar white matter)

**SCA: vertigo, ipsi limb dysmetria and gait ataxia, ispi intention tremor, ipsi Horners, Contralateral limb and trunk hemianalgesia/thermoanesthesia, contra CN IV palsy

v. Posterior cerebral a. (PCA)1. Rostral midbrain2. Caudal diencephalon3. Medial/inferior temporal and occipital lobes**PCA: Aphasia if Pulvinar involved, Akinetic mutism, Global amnesia, Transient contra hemiparesis4. Calcarine a.

a. Primary visual cortex – causes homonymous hemianopsia with macular sparing.

Medulla Midbrain

Pons

Brainstem images © Mosby 2007