Spontaneous Cervical and Intracranial Arterial Dissections

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Background
-Arterial dissections can cause stroke in both young in old populations, and is the most common cause of stroke in the young

-Extracranial dissection is more common than intracranial dissection

-Stroke is generally caused by either diminished blood flow from intraluminal thrombus or embolized clot


Pathogenesis (stick with it)
-Dissection are believed to begin with a tear in the media of the vessel wall, leading to bleeding in the wall itself

-partially coagulated intramural blood can enter the lumen which activates platelets and
the coagulation cascade leading to intraluminal thrombus.

-Intramural blood can accumulate leading to compression of the lumen



Risk Factors
-Connective tissue and vascular disorders are thought to be main risk factors:
(e.g. Ehlers-Danlos Syndrome (type IV), Marfan Syndrome, Polycystic kidney disease, cystic medial necrosis, Fibromuscular dysplasia)

-many are caused by trauma




Diagnosis
-based on radiologic criteria taken from the Strategies Against Stroke Study for Young Adults in Japan (SASSY) using CTA or MRI/MRA

-Primary rules are based on finding an intimal flap or double lumen on Angiogram or MRI/MRA, or repeated non-specific findings associated with dissection on multiple studies.



Symptoms
-Head or neck pain

-Horner Syndrome - occurs when the sympathetic fibers on the ICA are stretched. It is usually just partial with ptosis and miosis but no anhidrosis.


Difference between Carotid and Vertebral Dissections
-Transient monocular blindness occurred only with internal carotid dissection

-Ischemic stroke is more common in vertebral dissections

-Neck pain and recent minor cervical trauma are more common in vertebral dissections

-Proportion of men and a recent infection are more common in ICA



Treatment
-Antithrombotic therapy (antiplatelet or anticoagulation) is the primary initial treatment for ischemic stroke and TIA caused by arterial dissection

-For intracranial dissection, antiplatelet therapy is often the treatment of choice

-For extracranial dissection, anticoagulation initially followed by 6 months of warfarin therapy as opposed to antiplatet therapy is often chosen

-Endovascular and surgical therapy are generally only reserved for recurrent ischemic events


BOTTOM LINE:
-arterial dissection is more common cause of stroke in the young
-extracranial (vertebral, carotid) more common than intracranial dissection
-sx: headache, neck pain, stroke-like symptoms, Horner's syndrome (for ICA)
-risk factors: connective tissue disorders, trauma
-dx: angiography, MRI/MRA
-tx: antithrombotics/anticoagulation (aspirin, heparin, coumadin, etc.); surgical/endovascular for recurrent events


Submitted by J. Grover.


Reference(s): Caplan, LR and Biousse V. “Cervicocranial Artery Dissections.” J Neuro-Opthalmol. 2004; 24:299-305. Maruyama, H et al. “Spontaneous Cervicocephalic Arterial Dissection with Headache and Neck Pain as the Only Symptom.” J Headache Pain (2012) 13: 247-253. “Spontaneous Cerebral and Cervical Artery Dissection: Treatment and Prognosis”. Uptodate.  “Spontaneous Cerebral and Cervical Artery Dissection: Clinical Features and Diagnosis”. Uptodate., picture