[Transient paraparesis as a manifestation of left carotid stenosis]

Paraparesis caused by a cerebrovascular disorder is infrequent, although it is seen in infraction of both anterior cerebral arteries (ACA), in vertebrobasilar insufficiency syndromes or in infarction of the border zones of the anterior circulation.

Male aged 52 years, right handed, with a history of high blood pressure, who visited because of two episodes of transient paraparesis that lasted 5 minutes and 15 hours. During the last episode the presence of paraparesis and left Babinski sign were observed. Complementary explorations conducted to test for medullar pathology were negative. Cranial MRI showed only bilateral lacunar infarctions in deep territories. Four months later, the patient presented an episode of motor aphasia and paresthesia of the right lower limb, which remitted spontaneously in 10 minutes. Echo Doppler exploration of the supra aortic trunks showed significant stenosis of the left internal carotid artery (LICA) and occlusion of the right artery (RICA). Arteriography of the supra aortic trunks revealed a 99% stenosis of the RICA and 95% of the LICA, with vascularisation of both ACA dependent on the LICA. A left carotid endarterectomy was performed and the patient has remained asymptomatic to date.

In our patient, both ACA depended on the flow from the LICA. We therefore consider that the symptoms of transient paraparesis were secondary to the left carotid stenosis, either due to a haemodynamic or an artery to artery embolic mechanism.