associated with biological inflammation in spontaneous carotid dissection. Eur Radiol 2009; 19:2255. 156. Silverman IE, Wityk RJ. Transient migraine-like symptoms with internal carotid artery dissection. Clin Neurol Neurosurg 1998; 100:116. Topic 14082 Version 37.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 24/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate GRAPHICS The progression of a dissection, thrombus development, and total vessel occlusion Courtesy of Dr. Mounzer Kassab. Graphic 57866 Version 2.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 25/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Mechanism of dissecting aneurysm formation Lateral and cross-sectional schematic view of the carotid artery. (A) Aneurysmal dilatation of the vessel related to a hemorrhage between the media and the adventitia (subadventitial dissection). (B) Communication between the arterial lumen and the dissection cavity or disappearance of the hematoma may lead to the formation of an extraluminal pouch or a fusiform dilatation. Reproduced with permission from: Guillon B, Brunereau L, Biousse V, et al. Long-term follow-up of aneurysms developed during extracranial internal carotid artery dissection. Neurology 1999; 53:117. Copyright 1999 Lippincott Williams & Wilkins. Graphic 57174 Version 4.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 26/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Segments of the vertebral artery The vertebral artery is divided into four anatomic segments: V1 Origin of the vessel to the foramina of the sixth cervical (C6) transverse process. V2 Intraforaminal segment from the sixth to the second cervical vertebral body (C6 to C2). V3 From the second cervical (C2) foramina to the base of the skull. V4 Intracerebral segment of the vertebral artery. The vertebral arteries merge to form the basilar artery and are intradural. Graphic 56466 Version 6.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 27/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Pathology of internal carotid artery dissection Elastica van Gieson stain of specimens from a 61-year-old man with internal carotid artery dissection and fibromuscular dysplasia. (A) Postmortem exposition of intramural hematoma of the right internal carotid artery above the bifurcation (arrow). (B) Cross-section of the dissected artery shows subintimal and intramedial hematoma (small arrows). (C) Longitudinal section with zipper-like separation within the arterial wall (large arrow) corresponding to the false lumen and myxoid degeneration of the media (small arrows). Asterisk: true lumen; Scale bar: 0.25 mm. Reproduced with permission from: Besselmann M, Vennemann B, Lowens S, et al. Internal carotid artery dissection. Neurology 2000; 54:442. Copyright 2000 Lippincott Williams & Wilkins. Graphic 73102 Version 4.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 28/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Horner syndrome due to internal carotid artery dissection (A) Horner syndrome (miosis and ptosis). (B) Multiple left frontoparietal acute ischemic lesions on diffusion- weighted MRI. (C) Carotid angiography with evidence of left extracranial internal carotid artery occlusion. (D) Internal carotid artery mural hematoma due to dissection evident on MRI scan. https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 29/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate (E) Intimal flap (arrows) appearance on Duplex scan, a pathognomonic sign of dissection. Reproduced with permission from: Mazzucco S, Rizzuto N. Teaching NeuroImage: Horner syndrome due to internal carotid artery dissection. Neurology 2006; 66:E19. Copyright 2006 Lippincott Williams & Wilkins. Graphic 80623 Version 5.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 30/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Isolated hypoglossal nerve palsy due to internal carotid artery dissection (A) The patient's tongue deviated to the left. (B) T1-weighted MRI demonstrates narrowing of the lumen and intramural hematoma in the left internal carotid artery. (C) True fast MRI with steady-state precession reveals the anatomic juxtaposition of the hypoglossal nerve (arrowhead) and the dissected internal carotid artery (arrow). Reproduced with permission from: Okunomiya T, Kageyama T, Suenaga T. Teaching NeuroImages: Isolated hypoglossal nerve palsy due to internal carotid artery dissection. Neurology 2012; 79:e37. Copyright 2012 Lippincott Williams & Wilkins. Graphic 86467 Version 4.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 31/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate String sign on MR angiography Left internal carotid artery dissection in a 43-year-old man. A hemorrhagic crescent on axial T1 cervical MRI (A) and the string sign on follow-up neck MR angiography (B) are consistent with dissection. MRI: magnetic resonance imaging; MR: magnetic resonance. Reproduced with permission from: Pary LF, Rodnitzky RL. Traumatic internal carotid artery dissection associated with taekwondo. Neurology 2003; 60:1392. Copyright 2003 Lippincott Williams & Wilkins. Graphic 65212 Version 6.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 32/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Flame-shaped occlusion of internal carotid artery from dissection Digital subtraction angiogram (lateral projection) shows an internal carotid artery occlusion secondary to dissection, as indicated by the typical flame- shaped appearance and location of the occlusion distal to the carotid bifurcation. Reproduced with permission from: Koch S, Lorenzo D, Rabinstein AA, Lam B. Ischemic optic neuropathy and carotid dissection. Neurology 2005; 64:827. Copyright 2005 Lippincott Williams & Wilkins. Graphic 61851 Version 5.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 33/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Intracranial dissection with intimal flap (A, B) Diffusion-weighted sequence of MRI of the brain shows acute infarction in the right MCA territory. (C, D) Catheter angiography showed irregularities of the right supraclinoid internal carotid artery, extending into the M1 segment of the right MCA. An intimal flap (arrow) indicates dissection. MRI: magnetic resonance imaging; MCA: middle cerebral artery. Reproduced with permission from: Suter B, El-Hakam LM. Child neurology: stroke due to nontraumatic intracranial dissection in a child. Neurology 2009; 72:e100. Copyright 2009 Lippincott Williams & Wilkins. Graphic 55635 Version 6.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 34/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Extracranial aneurysm of the internal carotid artery Arteriography of an extracranial aneurysm of the internal carotid artery at the skull base resulting from carotid dissection in a 34-year-old man. Reproduced with permission from: Meairs S, Hennerici M. Long-term follow-up of aneurysms developed during extracranial internal carotid artery dissection. Neurology 2000; 54:2190. Copyright 2000 Lippincott Williams & Wilkins. Graphic 80873 Version 5.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 35/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate MRI of ICA dissection Axial T1-weighted MRI showing a right internal carotid artery dissection as a crescent-shaped hypersignal within the internal carotid artery wall. MRI: magnetic resonance imaging; ICA: internal carotid artery. Graphic 59392 Version 3.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 36/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Etiologies of thunderclap headache Most common causes of thunderclap headache: Subarachnoid hemorrhage Reversible cerebral vasoconstriction syndromes (RCVS) Conditions that less commonly cause thunderclap headache: Cerebral infection (eg, meningitis, acute complicated sinusitis) Cerebral venous thrombosis Cervical artery dissection Spontaneous intracranial hypotension Acute hypertensive crisis Posterior reversible leukoencephalopathy syndrome (PRES) Intracerebral hemorrhage Ischemic stroke Conditions that uncommonly or rarely cause thunderclap headache: Pituitary apoplexy Colloid cyst of the third ventricle Aortic arch dissection Aqueductal stenosis Brain tumor Giant cell arteritis Pheochromocytoma Pneumocephalus Retroclival hematoma Spinal epidural hematoma Varicella zoster virus vasculopathy Vogt-Koyanagi-Harada syndrome Disputed causes of thunderclap headache: Sentinel headache (unruptured intracranial aneurysm)* Primary thunderclap headache Sentinel headache due to an unruptured intracranial aneurysm is a possible cause of thunderclap headache, but supporting data are weak. https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 37/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate There is controversy as to whether thunderclap headache can occur as a benign and potentially recurrent headache disorder in the absence of underlying organic intracranial pathology. Graphic 81710 Version 8.0 https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 38/39 7/6/23, 12:24 PM Cerebral and cervical artery dissection: Clinical features and diagnosis - UpToDate Contributor Disclosures David S Liebeskind, MD Consultant/Advisory Boards: Cerenovus [Stroke]; Genentech [Stroke]; Medtronic [Stroke]; Stryker [Stroke]. Speaker's Bureau: Astra-Zeneca [Stroke]. All of the relevant financial relationships listed have been mitigated. Scott E Kasner, MD Grant/Research/Clinical Trial Support: Bayer [Stroke]; Bristol Meyers Squibb [Stroke]; Medtronic [Stroke]; WL Gore and Associates [Stroke]. Consultant/Advisory Boards: Abbvie [Stroke]; AstraZeneca [Stroke]; BMS [Stroke]; Diamedica [Stroke]; Medtronic [Stroke]. All of the relevant financial relationships listed have been mitigated. John F Dashe, MD, PhD No relevant financial relationship(s) with ineligible companies to disclose. Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence. Conflict of interest policy https://www.uptodate.com/contents/cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis/print 39/39