<unk>  in ultrasound The causes of internal<unk>  can be broadly categorized into two classes: spontaneous or traumatic. Spontaneous Once considered uncommon, spontaneous<unk>  is an increasingly recognized cause of stroke that preferentially affects the middle-aged. The incidence of spontaneous<unk>  is low, and incidence rates for internal<unk>  have been reported to be 2.6 to 2.9 per 100,000. Observational studies and case reports published since the early 1980s show that patients with spontaneous internal<unk>  may also have a history of stroke in their family and/or hereditary connective tissue disorders, such as Marfan syndrome, Ehlers-Danlos syndrome, autosomal dominant polycystic kidney disease, pseudoxanthoma elasticum, fibromuscular dysplasia, and osteogenesis imperfecta type I. IgG4-related disease involving the<unk>  artery has also been observed as a cause. However, although an association with connective tissue disorders does exist, most people with spontaneous arterial<unk> s do not have associated connective tissue disorders. Also, the reports on the prevalence of hereditary connective tissue diseases in people with spontaneous<unk> s are highly variable, ranging from 0% to 0.6% in one study to 5% to 18% in another study. Internal<unk>  can also be associated with an elongated styloid process (known as Eagle syndrome when the elongated styloid process causes symptoms). Traumatic<unk>  is thought to be more commonly caused by severe violent trauma to the head and/or neck. An estimated 0.67% of patients admitted to the hospital after major motor vehicle accidents were found to have blunt<unk>  injury, including intimal<unk> s, pseudoaneurysms, thromboses, or fistulas. Of these, 76% had intimal<unk> s, pseudoaneurysms, or a combination of the two. Sports-related activities such as surfing and Jiu-Jitsu have been reported as causes of<unk> . The probable mechanism of injury for most internal<unk>  injuries is rapid deceleration, with resultant hyperextension and rotation of the neck, which stretches the internal<unk>  artery over the upper cervical vertebrae, producing an intimal tear. After such an injury, the patient may remain asymptomatic, have a hemispheric transient ischemic event, or suffer a stroke. Artery<unk>  has also been reported in association with some forms of neck manipulation. There is significant controversy about the level of risk of stroke from neck manipulation. It may be that manipulation can cause<unk> , or it may be that the<unk>  is already present in some people who seek manipulative treatment. At this time, conclusive evidence does not exist to support either a strong association between neck manipulation and stroke, or no association.
Carotid artery dissection
Vertebral artery dissection
Carotid artery stenosis
Cirsoid aneurysm
Arterial tortuosity syndrome
Arterial embolism
Charcot–Bouchard aneurysm
Middle cerebral artery syndrome