Posterior Cerebral Artery Symptoms 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 Artery Symptoms 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 Infarcts Etiology: –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 infarcts Lateral medullary infarcts (Wallenberg’s Syndrome) Etiology: –Infarction of the lateral medulla and cerebellum caused by PICA occlusion –Sudden in 40%, may be progressive over hr or present as TIA –Vertebral artery dissection in 75% of cases

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