Carotid syndromes

Recall the right ica arises at the sternoclavicular notch from the inominate artery and the left cca comes directly from the aortic arch. Division to eca and ica occurs at C4 level. CCA occlusion is less than one percent but can become atheromatous at origin especially on the left side. Midcommon carotid occlusion typically occurs postradiation.

ICA occlusion is clinically silent 30-40 percent of the time.

Won't go over every syndrome but a few unusual ones. If one carotid occludes and later the other one occludes, a bilateral cerebral infarction can occur with coma, quadriplegia, and continuous horizontal metronomic conjugate eye movements.

Headaches as a rule are above the eyebrow but is not invariable. MCA headaches may be more lateral eg. temple; pca headaches may be in or behind the eye.

Watershed strokes are 2 types. Cortical watershed and deep watershed (lenticulostriates) due to carotid stenosis tend to produce shoulder/hip weakness (man in barrel). If longstanding it may go toward mca affecting face or motor aphasia.

In case of circulatory collapse get multiple border zone infarcts.

TMB occurs prior to stroke in 10-25 percent of cases of symptomatic carotid occlusion.

Anterior choroidal artery exits just after posterior communicating artery, supplies the globus pallidum interna and posterior limb of capsule, and contiguous structures including optic tract. Occlusion causes contralateral hemiplegia, hemihypesthesia, and homonymous hemianopia without a behavioral component in most cases. However, Decroix studied 16 patients and noted that some suffered spatial neglect and costructional apraxia (right sided ones) or mild aphasia (left sided ones). Stroke occurs in posterior limb of capsule, encroaches on the tip of the globus pallidus laterally. Visual defect typically spares the horizontal meridian due to LGB involvement. Bilateral anterior choroidal strokes result in acute pseudobulbar mutism, facial diplegia, hemiparesis, hemisensory loss,lethargy, neglect and affective symptoms.