Spondylolisthesis occurs when a vertebrae slides on top of another vertebrae. It can be present at birth or be caused by an injury to the vertebrae. It is cause by a defect in the locking mechanism of the articular processes of the vertebrae. This defect, often a stress fracture or weakening of the bone, occurs in the junction of the pedicle and lamina of the vertebral body. When this joint is weakened it allows separation of the vertebral body, lamina, and inferior articular process from the rest of the vertebrae causing it to “fall” forwards. Athletes who participate in high impact sports are at a higher risk for spondylolisthesis. Males tend to get the disease more often than females, but this may be due to males doing higher impact activities. Although it seems that it would be an adult disease, spondylolisthesis is most common in children between the ages of seven and ten. There is a grading scale that is utilized to tell the amount of disease process. Grade One involves only about one-fourth of the vertebrae that has slipped forward. Grade Two equals fifty percent of the vertebrae is involved, Grade three is seventy-five percent and so on. A Grade five means that the vertebral body has completely slipped forward onto the inferior vertebrae, known as spondyloptosis. Many people with spondylolisthesis do not have any back complaints. Some of the more common symptoms include LBP, increased lordosis of the lumbar spine, pain in the thighs or legs, and differences in posture.

Information for this blog was found at the following websites:

http://www.spineuniverse.com/displayarticle.php/article114.html

http://emedicine.medscape.com/article/396016-overview

Carotid artery dissection is a very rare occurrence which involves a tear or break forming in the carotid artery of the neck. A dissection occurs when the lining and/or wall of the artery tears. This tear can either be complete or only partial. When a partial tear occurs, the inner lining of the artery pulls away from the outer lining and causes a second lumen, or hole, to form. Carotid artery dissections are very serious because they can quickly cause an intracranial aneurysm which could lead to a subarachnoid bleed. Dissections outside of the cranium rarely form aneurysms. Carotid artery dissections are responsible for up to twenty percent of strokes in young adults, although this percentage is thought to be higher because many go undiagnosed. They are the leading cause of ischemic strokes in persons under the age of fifty. These dissections can be cause by a number of reasons either spontaneous or through trauma. One should be especially concerned about a possible dissection when direct trauma or stress occurs at the cervical level. Dissections can also occur from quick movements of the neck or by holding the neck in the same position for extended amounts of time. Carotid artery dissections have been noted in patients who were doing sports activities, had appointments with the chiropractor, and who were doing overhead painting. In extremely rare cases, dissection can occur simply by sneezing or coughing. Dissections inside the cranium are extremely rare because the skull absorbs most of the impact in traumatic events. The most common symptoms of a dissection are a headache occurring on the opposite side of the dissection, bruising and swelling of one side of the neck, visual disturbances such as flashing and arcing lights, blindness due to decreased blood flow to the retina, decreased taste, and pain of the face, head, and neck. Smoking, oral birth control, respiratory tract infections, high blood pressure, and genetics all increase your susceptibility of having a spontaneous dissection. Dissections can be diagnosed through ultrasound, MRI/MRA, CTA, or angiography, which had been the standard diagnosing tool for many years until recently. Patients with a Carotid artery dissection have a good prognosis if it is caught early. Patients are often medicated with Heparin or some type of thrombolytic medication. Surgery is often not required but in some cases patients must have a balloon stenting procedure done.

For more information on Carotid artery dissection visit the following websites:

http://www.medscape.com/viewarticle/410652_3
http://emedicine.medscape.com/article/757906-overview

Ranulas are a type of cyst that affect the major salivary glands. These cysts occur when mucous extravasates into surrounding tissue. There are cervical ranulas and oral ranulas. Cervical ranulas can sometimes appear to be a unilateral, bluish, translucent neck mass.. They can be caused by trauma or blockage of the excretory duct which does not allow the duct to drain mucous properly. Ranulas are most often asymptomatic or have no symptoms, but sometimes patients can have trouble swallowing or chewing and can have trouble breathing. Oral ranulas often cause swelling of the floor of the mouth but is not painful. Females tend to get oral ranulas while males tend to get cervical ranulas. These cysts most often occur in younger adults and older children under the age of twenty. These lesions usually grow quickly but only last about three to six weeks; or until they rupture. This happens spontaneously. Patients who have had a ranula can expect to get one again as they are often chronic in nature. HIV can increase your risk of getting a ranula. Ranulas are often diagnosed by a CT or MRI scan. They appear as a smooth, well-outlined cystic lesion in the oral or neck area. They can sometimes have a slightly increased attenuation. When a ranula is infected is cannot be differentiated from an abcess on a CT. T1 and T2 weighted imaging sequences are utilized in an MRI for a ranula. If a ranula does not heal itself, an excision can be made in order to drain the mucous from the tissue.
All information was taken from the following websites:
http://www.learningradiology.com/archives05/COW%20146-Ranula/ranulacorrect.htm
http://emedicine.medscape.com/article/1076717-overview