Cervical artery dissection is

dissection Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause o ...

of one of the layers that compose the

carotid In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid"
in
vertebral artery The vertebral arteries are major arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry o ...

in the neck (cervix). They include: *

Carotid artery dissection Carotid artery dissection is a separation of the layers of the artery wall supplying oxygen-bearing blood to the head and brain and is the most common cause of stroke in young adults. ( Dissection is a blister-like de-lamination between the out ...

, a separation of the layers of the artery wall supplying oxygen-bearing blood to the head and brain. *

Vertebral artery dissection Vertebral artery dissection (VAD) is a flap-like tear of the inner lining of the vertebral artery, which is located in the neck and supplies blood to the brain. After the tear, blood enters the arterial wall and forms a blood clot, thickening t ...

, a flap-like tear of the inner lining of the vertebral artery that supply blood to the brain and spinal cord. Cervical dissections can be broadly classified as either "spontaneous" or traumatic. Cervical artery dissections are a significant cause of strokes in young adults. A dissection typically results in a tear in one of the layers of the arterial wall. The result of this tear is often an intramural

hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...

and/or aneurysmal dilation in the arteries leading to the intracranial area. Signs and symptoms of a cervical artery dissection are often non-specific and can be localized or generalized. There is no specific treatment, although most patients are either given an anti-platelet or anti-coagulation agent to prevent or treat strokes.

Epidemiology

Cervical artery dissection has been noted to be a common cause of young adult strokes, with some sources indicating a prevalence of up to 20% in this young adult population with annual incidence rates between 2.6 and 2.9 per 100,000, although these incidences may be misleading with true incidences being higher because clinical presentations can vary, many being minor or self-limited, and thus these dissections can go undiagnosed. In population-based studies, the peak age of presentation is approximately 45 years with a slight gender predisposition towards males (53-57%). Cervical arteries, as mentioned above, consist of two pairs of arteries: vertebral and carotid. As such, cervical artery dissection can be further categorized based on the involvement of artery: carotid vs. vertebral, and the location of the dissection:

intracranial The cranial cavity, also known as intracranial space, is the space within the skull that accommodates the brain. The skull minus the mandible is called the ''cranium''. The cavity is formed by eight cranial bones known as the neurocranium that in ...

vs. extracranial.

Causes

The two main causes of cervical artery dissection can be broadly categorized as either spontaneous or traumatic. Arterial walls are composed of three layers: an intima (the innermost layer), media (the middle muscular layer), and adventitia (the outermost layer). A tear in one of the layers of the arterial walls can result in blood collecting within a pocket between the layers of the artery, which can result in an intramural hematoma and/or aneursymal dilation. At the moment, there is no definitive location for the dissection, with some believing dissection initially occurs within the connective tissue and vasa vasorum of the media while others believe dissection begins with an intimal tear.

Spontaneous

Spontaneous cervical artery dissections are dissections that occur without any trauma to the neck. More specifically, this can include potential causes such as hereditary connective tissue diseases, family history of

stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

s, infections and other miscellaneous causes such as smoking,

hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high bl ...

migraine Migraine (, ) is a common neurological disorder characterized by recurrent headaches. Typically, the associated headache affects one side of the head, is pulsating in nature, may be moderate to severe in intensity, and could last from a few hou ...

s and

contraceptive Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth contr ...

use. Hereditary connective tissue diseases include autosomal

polycystic kidney disease Polycystic kidney disease (PKD or PCKD, also known as polycystic kidney syndrome) is a genetic disorder in which the renal tubules become structurally abnormal, resulting in the development and growth of multiple cysts within the kidney. These cy ...

, Ehlers-Danlos syndrome,

Marfan syndrome Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with long arms, legs, fingers, and toes. They also typically have exceptionally flexible joints a ...

fibromuscular dysplasia Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory disease of the blood vessels that causes abnormal growth within the wall of an artery. FMD has been found in nearly every arterial bed in the body although the most common ...

, and

osteogenesis imperfecta Osteogenesis imperfecta (; OI), colloquially known as brittle bone disease, is a group of genetic disorders that all result in bones that break easily. The range of symptoms—on the skeleton as well as on the body's other organs—may be mi ...

type 1 although studies have shown that the link between hereditary connective tissue diseases and cervical artery dissection is low, ranging from 0-0.6% in one study and 5-18% in another study.

Traumatic

Traumatic cervical artery dissections are dissections that occur after any sort of trauma to the neck, ranging from minor trauma such as nose-blowing or sneezing to severe trauma such as roadside accidents. Most traumatic dissections are secondary to some form of rapid decelerations injuries resulting in hyperextension or hyperflexion with rotational injury of the neck.

Pathophysiology

Cervical artery dissections begin initially with a small tear in the innermost layer of the arterial wall, the

tunica intima The tunica intima (New Latin "inner coat"), or intima for short, is the innermost tunica (layer) of an artery or vein. It is made up of one layer of endothelial cells and is supported by an internal elastic lamina. The endothelial cells are in ...

, or rupture of the

vasa vasorum Vasa vasorum are small blood vessels that comprise a vascular network supplying the walls of large blood vessels, such as elastic arteries (e.g., the aorta) and large veins (e.g., the venae cavae). The name derives . Occasionally two different ...

with bleeding within the media. As the arterial wall begins to tear, blood begins to enter this newly formed false lumen and the resulting hematoma formation can either narrow (stenosis) or occlude the artery, decreasing or completely blocking blood flow through the artery. A complete occlusion of the artery can result in cerebral ischemia as the brain is depleted of oxygen-rich blood. Because the brain has a pair of carotid and vertebral arteries on each side of the neck, a unilateral occlusion can be asymptomatic, as the bilateral circulation continues perfusing the brain. Thrombus formation is the natural physiologic response to the vascular injury to prevent significant blood loss. However, parts of the thrombus can break apart and result in emboli that can lodge themselves in distal cerebral arteries causing ischemic stroke, otherwise known as a cerebral infarction.

Signs and Symptoms

* The signs and symptoms of cervical artery dissection are often non-specific or generalized and can either develop acutely or over several days. * Headache * Visual disturbances (i.e.

diplopia Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often v ...

, ptosis) *

Tinnitus Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...

* Neck and face pain * Horner syndrome (often partial) * Loss of taste *

Anosmia Anosmia, also known as smell blindness, is the loss of the ability to detect one or more smells. Anosmia may be temporary or permanent. It differs from hyposmia, which is a decreased sensitivity to some or all smells. Anosmia can be due to a num ...

* Unilateral weakness *

Stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

Imaging

Various imaging modalities can be used for the diagnosis of cervical artery dissection. The diagnosis of cervical artery dissection can be confirmed with the presence of a mural hematoma on

ultrasound Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...

(US) or

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...

(MRI) and will also guide therapeutic decision making. MRI, with a fat-suppressed T1 sequence, is often first-line imaging. However, other modalities exist with helical computed topographic angiography (CTA) becoming the new gold-standard.

Magnetic resonance angiography Magnetic resonance angiography (MRA) is a group of techniques based on magnetic resonance imaging (MRI) to image blood vessels. Magnetic resonance angiography is used to generate images of arteries (and less commonly veins) in order to evaluate t ...

(MRA) and doppler US can also be utilized as additional non-invasive imaging techniques. The purpose of these imaging techniques is often multi-functional. These imaging modalities can detect the direction and changes of blood flow within the arteries and whether the dissection has resulted in any damage to brain tissue.

Treatment

The primary goal of treatment in cervical artery dissection is preventing or treating a stroke. Treatment guidelines also depend on the presence of underlying connective tissue disorders, dissection secondary to trauma, and underlying medical conditions. Management is often using either antiplatelet agents (i.e. aspirin) or anti-coagulation to prevent development of thrombus.

Antiplatelet drug An antiplatelet drug (antiaggregant), also known as a platelet agglutination inhibitor or platelet aggregation inhibitor, is a member of a class of pharmaceuticals that decrease platelet aggregation and inhibit thrombus formation. They are effectiv ...

s can be given as individual drugs, or in combination (i.e. aspirin alone, or aspiring and clopidogrel).

Anticoagulation Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where the ...

such as heparin, intravenously (IV) or injectable (shot) can be given while inpatient and followed by heparin. A recent trial in 2015, the Cervical Artery Dissection in Stroke Study (CADISS), examined the efficacy of antiplatelet and anticoagulation treatment with the primary endpoint of ipsilateral stroke or death in individuals with symptomatic dissections. The CADISS trial revealed no significant difference in efficacy of antiplatelet and anticoagulant drugs in preventing strokes or death, but did note that strokes were rare in either group, and rarer than what has been reported in observational studies.

References

{{Reflist Human anatomy