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 the artery wall and often impeding blood flow. The symptoms of vertebral artery dissection include head and neck pain and intermittent or permanent stroke symptoms such as difficulty speaking, impaired coordination and visual loss. It is usually diagnosed with a contrast-enhanced CT or MRI scan.Vertebral dissection may occur after physical trauma to the neck, such as a blunt injury (e.g. traffic collision), or strangulation, or after sudden neck movements, i.e. coughing, but may also happen spontaneously. 1–4% of spontaneous cases have a clear underlying connective tissue disorder affecting the blood vessels. Treatment is usually with either antiplatelet drugs such as aspirin or with anticoagulants such as heparin or warfarin.Vertebral artery dissection is less common than carotid artery dissection (dissection of the large arteries in the front of the neck). The two conditions together account for 10–25% of non-hemorrhagic strokes in young and middle-aged people. Over 75% recover completely or with minimal impact on functioning, with the remainder having more severe disability and a very small proportion (about 2%) dying from complications. It was first described in the 1970s by the Canadian neurologist C. Miller Fisher. Classification
Vertebral artery dissection is one of the two types of dissection of the arteries in the neck. The other type, carotid artery dissection, involves the carotid arteries.
Yersiniosis is an infectious disease caused by a bacterium of the genus Yersinia. In the United States, most yersiniosis infections among humans are caused by Yersinia enterocolitica. Infection with  Y. enterocolitica occurs most often in young children. The infection is thought to be contracted through the consumption of undercooked meat products, unpasteurized milk, or water contaminated by the bacteria. It has been also sometimes associated with handling raw chitterlings.Another bacterium of the same genus, Yersinia pestis, is the cause of Plague. Signs and symptoms
Infection with Y. enterocolitica can cause a variety of symptoms depending on the age of the person infected. Common symptoms in children are fever, abdominal pain, and diarrhea, which is often bloody. Symptoms typically develop 4 to 7 days after exposure and may last 1 to 3 weeks or longer. In older children and adults, right-sided abdominal pain and fever may be the predominant symptoms, and may be confused with appendicitis. In a small proportion of cases, complications such as skin rash, joint pains, ileitis, erythema nodosum, and sometimes sepsis, acute arthritis or the spread of bacteria to the bloodstream (bacteremia) can occur. Diagnosis
Phage typing of bacterial culture or antibodies for F-antigen. Treatment
Treatment for gastroenteritis due to Y. enterocolitica is not needed in the majority of cases. Severe infections with systemic involvement (sepsis or bacteremia) often requires aggressive antibiotic therapy; the drugs of choice are doxycycline and an aminoglycoside. Alternatives include cefotaxime, fluoroquinolones, and co-trimoxazole. References


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