Posterior Cerebral ArterySymptoms and signs:• Postcommunal PCA

– Ventrolateral thalamus • sensory symptoms, usually paresthesias• Motor symptoms include mild hemiparesis, clumsiness and ataxia

– PCA hemispheric infarction:• Contralateral homonymous hemianopia (striate cortex, optic radiation)• Macular region is often spared if occipital pole not affected

Posterior Cerebral ArterySymptoms and signs:• Dominant hemisphere infarction:

– Alexia without agraphia(splenium of corpus callosum)

– Visual agnosia (medial temporal lobe)

• Non dominant hemisphere:– Neglect of contralateral visual field

– Constructional apraxia

Panhemispheric InfarctsEtiology:

– Total or partial anterior circulation occlusion– 17% of strokes

Symptoms and signs:– Variété massive de l`hemiplégie (MCA)– Delayed (48-72hr) impaired consciousness

Panhemispheric Infarcts

Medullary infarcts

Anatomy and supply areas:perforating branches from PICA, AICA, basilar

Medullary infarctsLateral medullary infarcts (Wallenberg’s Syndrome)

• Etiology:– Infarction of the lateral medulla and cerebellum caused by PICA occlusion– Sudden in 40%, may be progressive over 24-48hr or present as TIA– Vertebral artery dissection in 75% of cases

Medullary infarcts

Medullary infarcts

Medullary infarcts• Symptoms and signs:

– Gait ataxia– Vertigo– Ipsilateral limb clumsiness(cerebellar)– Hypoesthesia of contraleral limbs(crossed spinothalamic) and ipsilateral face(uncrossed trigeminal)– Ipsilateral Horner’s– If AICA involved(lateral inferior pons)

• Deafness, tinnitus, facial paresis

Lacunar Syndromes• Occlusion of small perforating arteries

• 80% of lacunes are silent

• Pure motor stroke– Commonest lacunar syndrome

– Usually involves antrior part of posterior limb or internal capsule

– Can occur also from basis pontis lacune

• Pure sensory stroke:– Only 6% of total lacunar strokes

– Thalamus or anterior limb of internal capsule

References

• Stroke Syndromes: Bogousslavsky and Caplan eds. Cambridge University press 1995

• Introduction to cerebral angiography: A.G. Osborn auth, Harper and Row publishers, 1980