Neurological Sciences | 2021
“Don’t call me from the left side…”: ischemic stroke in a patient with uncommon vertebral artery dissection
Abstract
Cervical artery dissection is an important cause of stroke in young and middle-aged patients [1]. Dissection can be either spontaneous, whose pathogenesis is unknown, or traumatic, with a wide range of trauma severity ranging from serious events (i.e., high-speed motor vehicle crash), to subtle ones (hyperextension or lateroversion of the neck) [2]. Here, we describe a case of ischemic stroke in a young adult due to vertebral artery dissection, probably related to a focal trauma of the wall vessel secondary to an ectopic cervical course over the hyoid bone. A 42-year-old Tunisian woman with a history of migraine was admitted for wake-up-onset of headache associated with dizziness. Neurological examination in the emergency room (ER) showed gait imbalance and dysarthria. Brain CT did not detect parenchymal lesions, while CT angiography revealed acute basilar artery occlusion (BAO), with a focal stenosis of the right vertebral artery in the V2 tract (C4) probably related to vessel dissection (Fig. 1A and B). The vessel ran outside the transvers foramens of cervical vertebras, described a tight curve with an acute angle in correspondence of the hyoid bone, finally passing over its upper surface (Fig. 1C). Immediately after the radiological study, the patient presented clinical worsening with anarthria, severe left hemiparesis, and lateral gaze palsy (NIHSS: 17/42). Digital subtraction angiography (DSA) was performed in conscious sedation, confirmed BAO, and the ectopic course of the right vertebral artery, with its focal dissection (Fig. 1D). Direct mechanical revascularization of basilar artery with Trevo® Thrombectomy System was performed, with complete recanalization of the vessel (Fig. 1E and F). Off-label intravenous thrombolysis was not performed in order to minimize potential hemorrhagic risk. Medical anticoagulation with therapeutic dose of low molecular weight heparin, rather than antiplatelet agents, was started after the procedure to achieve complete recanalization of the extracranial tract of the vertebral artery. Brain MRI, performed after the endovascular procedure, revealed a small ischemic paramedian pontine lesion on the right side (Fig. 1G). The clinical status of the patient improved, and few days after the procedure, she presented only a mild left hemiparesis, with complete recovery after intensive rehabilitation; neurological examination at 90-day follow-up was completely normal. In conclusion, this report emphasizes the importance of endovascular treatment for outcome implications, which might provide also additional information in case of unusual etiologies of ischemic stroke. In this case, radiological examinations revealed an ectopic course of the vessel over the hyoid bone, which probably might be the underlying cause of the focal dissection. Rotational movements of the neck, particularly on the left side, may have caused the injury of the vertebral artery. This case might also be considered an atypical case of Bow Hunter’s syndrome (BHS), or rotational vertebral artery occlusion syndrome. BHS is an uncommon condition in which a vertebrobasilar insufficiency is caused by the rotation of the head to the contralateral side of the dominant vertebral artery [3]. In this specific case, repeated neck movements may have caused a continuous injury of the vertebral artery wall on a bone surface, leading to a dissection of the vessel and a thromboembolic event to the basilar artery. * Guido Bigliardi [email protected]