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

The Vein of Galen is a large blood vessel located at the base of the brain underneath the hemispheres. Its main job is to drain the anterior and central parts of the cerebellum into sinuses located in the posterior fossa. Vein of Galen malformations involve missing capillaries which result in a direct link between a cerebral artery and vein. This does not allow the blood to slow down and drop off its oxygen and other nutrients as it normally would. Instead the blood flows rapidly from artery to vein and rapidly moves to the heart which cannot withstand this rush of blood. These malformations almost always cause congestive heart failure. Vein of Galen malformations are congenital defects and are sometimes seen on ultrasounds. Babies born with these defects can also have hydrocephaly because the enlarged vessel blocks the flow of CSF from the brain. Children with V of G malformations can also experience seizures and headaches, are slower learners and show signs of respiratory distress and cyanosis at birth. Babies who show CHF as the predominant symptom often die before birth or shortly thereafter. Shunting can markedly reduce the symptoms of macrocephaly and can often greatly, if not completely improve the life of the child. The best treatement for this disorder is by embolization of the affected vessel. The blood supply to the vessel is re-routed by the placement of a “man-made” embolis. This blocking action allows the blood flow to the heart to return to normal and often times the symptoms of the malformation dissipate. This procedure can allow the patient to lead a normal and active life.
http://www.childrenshospital.org/clinicalservices/Site2162/mainpageS2162P16.html
http://emedicine.medscape.com/article/1179888-overview
http://www.veinofgalen.co.uk/vog.htm

Nasal polyps are a fairly rare condition that occurs in approximately one to four percent of adults. They are benign growths that appear on the mucosal lining of the nasal passages and are teardrop in shape. Nasal polyps are most often seen in the opening into a sinus. Polyps most often occur in those who experience chronic sinusitis, have asthma, and/or endure frequent nasal and sinus allergies. There is a slightly higher incidence in males than compared to females. These types of polyps are very rare in children but are sometimes seen in those that have been diagnosed with cystic fibrosis. Some common symptoms of nasal polyps are a runny nose, congestion, decreased sense of smell or taste, headaches, and itching around the eyes. These polyps can sometimes cause breathing difficulties depending on their size and origin. It is unknown why and how nasal polyps actually appear but they are thought to be influenced by many different factors such as allergies, family history, and age to name a few. It is thought that nasal polyps are caused when normal nasal and sinus mucosa swell and fill up with fluid. Others believe polyps are their own entity. There are a few different ways of testing for nasal polyps. One way is to have a nasal endoscopy performed. For this exam a doctor will place a scope, or small camera, up into the nostril into the nasal cavity and literally look for the polyps. Other ways include allergy tests, CT scans, and Cystic Fibrosis tests. Treatment often involves trying to shrink the polyp or completely get rid of it. Corticosteroids are often used to try and reduce the size of the polyp or polyps. Either a polypectomy or endoscopic surgery on the sinuses can be performed in order to remove the polyp from the nasal passage. The type of surgery depends on the size and amount of the polyps. Some of the best ways to reduce ones chances of having polyps is by using a nasal rinse or a nasal lavage of saline, managing ones allergies and asthma, practicing good hand hygiene and humidifying ones home.

All information used in this blog as well as additional information on nasal polyps can be found on the following websites:
Mayoclinic.com
http://emedicine.medscape.com/article/994274-overview

Coats disease is also known as: Coats’ Retinitis, Coats’ syndrome, Exudative Retinitis, and Retinal Telangiectasis. It is unknown what causes the disease, but it is possible that it is due to a genetic mutation. Coats’ disease is a very uncommon disease which occurs mostly in young males during under the age of ten. This disease causes the capillaries in the eyes to bust open and leak serum from the blood into the posterior portion of the eye.
The disease gradually worsens and in most cases only occurs unilaterally. Coats’ disease can be diagnosed with the use of Flouroscein Angiography which involves injecting the eye with dye and watching its circulatory system. There are five different stages of Coats’ disease which are classified according to the severity of the disease. The first stage is treatable with laser therapy which allows most of the patient’s vision to be saved. Unfortunately it is extremely uncommon to diagnose Coats’ disease in the first stage. Stage Two can still be treated. Usually photocoagulation and/or cryotherapy are used. At this stage vision can sometimes be restored. Most damage occurs to the central vision of the eye which cause difficulty in reading, watching television, and driving. Sometimes a dense nodule becomes visible during this stage which causes the patient’s eye to appear yellow. During Stage Three the retina of the eye can become totally detached. This can be fixed by having surgery to reattach the retina to the eye. In these cases, some vision may be recovered although the initial prognosis is not very good. At this point, damage to the retina is very severe and sometimes requires complete removal of the eye due to the severe pain that the disease sometimes causes. Stage five involves total blindness which is completely irreversible. This is only in rare cases. Coats’ disease often stops on its own and causes mild symptoms. If the patient’s pain is severe an enucleation of the affected eye is required.
All information used to create this blog can be found at:

http://www.coatsdisease.org/index.html

http://www.ncbi.nlm.nih.gov

Empty Sella Syndrome (ESS) is a disease that involves an enlarged sella turcica and in turn affects the pituitary gland and its functions. It is important to note that the pituitary gland itself is usually of normal size although it may be slightly smaller. Primary ESS occurs most often in obese women and women with high blood pressure. This form of ESS is caused by an anatomical defect that is superior to the pituitary gland and puts pressure along the sella turcica in turn squashing the pituitary along the walls of the sella turcica. This also involves a problem in the barrier that separates the sella turcica from the CSF around the brain. When these patients have ESS, the sella turcica will fill up with CSF causing it to look empty. Secondary ESS is caused by a complication of injury, surgery or radiation therapy. In this case, the pituitary gland shrinks within the sella turcica. Secondary ESS symptoms often include amenorrhea, infertility, and overall fatigue while primary ESS causes headaches and vision problems. In rare cases, CSF can leak from the nose or the patient will experience a chronic runny nose. Most often ESS is diagnosed on accident with the patient experiencing no symptoms. Patients presenting with symptoms will be tested with either a CT or MRI. Most often a pituitary function test is run in order to rule out any other hormone excess of deficiency. Most symptoms of ESS are mild and usually do not require any type of treatment. In more severe cases surgery can be done to reduce the pressure put on the sella turcica. More information on ESS can be found at the following websites:
http://www.healthsystem.virginia.edu/uvahealth/adult_endocrin/sella.cfm
http://www.medic8.com/neurological-disorders/emptysella.htm
http://endocrine-disorders.health-cares.net/empty-sella-syndrome.php

Otosclerosis involves an abnormal growth of bone which occurs in the middle ear. Otosclerosis most often manifests on the last bone of the inner ear, the stapes. Depending on which structures are involved, this disease can cause varying symptoms. The most common is hearing loss. Balance issues and tennitis are also often noted. In order to understand exactly what happens with otosclerosis, we must first understand how our hearing works. Our ears take sound waves and transfer them into electrical signals which in turn cause different nerve impulses. These two nerves, the vestibulocochlear nerve and the facial nerve, take these impulses and send them to our brains, which then gives us the impression of sound. Specific parts of our inner ear react to specific sounds which allow us to hear differing tones and pitches. When otosclerosis occurs, the ossicles are unable to vibrate correctly and transmit correct impulses to our brain. This is the specific reason why one experiences difficulty in hearing. Most people who have otosclerosis have the most difficulty in hearing low pitches and whispers. Otosclerotic hearing loss is most often experienced gradually over time. There is no known cause of otosclerosis, although there is a genetic predisposition to the disease. There is a higher chance of otosclerosis in white, middle-aged women, and possibly an increase during pregnancy or with a history of measles. There are a few options for patients who suffer from otosclerosis. If the symptoms are mild, many people are able to live fully with the disease. Others may choose to wear a hearing aid or get a cochlear implant, which does not get rid of the hearing loss but can improve it. Surgery can also be performed. This involves removal of the stapes and replacing it with a prosthetic. This surgery is known as a stapedectomy. Although no proof exists as to its effectiveness, some patients find relief by taking fluoride tablets, a type of dietary supplement. This is thought to cause the ossicles to harden more quickly and cause less symptoms as the disease progresses. This practice is not accepted by most health care professionals due to its unproven effects.

All information for this blog and any addition information on otosclerosis can be found at:
http://www.american-hearing.org/disorders/hearing/otosclerosis.html
www.nidcd.nih.gov/health/hearing/otosclerosis.asp

Primitive Neuroectodermal Tumors (PNETs) are tumors that primarily affect the soft tissue. It was first believed that these specific tumors came from stem cells although there is now evidence that shows they may also come from specialized cells as well. PNETs are a specific type of medulloblastoma, a highly malignant tumor of the brain. Medulloblastomas are the most common type of malignant brain tumor that occurs in children, representing about thirty percent of all cases. These types of tumors occur in only one percent of the adult population. Most of these tumors appear in the midline of the brain, although they are quite often found in the lateral portion of the cerebellum as well. PNETs often appear in children under the age of fifteen. There are also slightly higher rates in Caucasians and males as compared to African-American and females.
Unfortunately there are no pathognomonic signs or symptoms related to PNETs. Most symptoms are specific to the area where the tumor manifests or are caused by excess pressure on the brain. Some symptoms include irritability, loss of energy, vomiting, headaches, and vision, hearing, and balance changes. Some children, specifically under the age of two, also have an increased head circumference. Depending on the size and location of the tumor, most people will not die from a PNET. Although it is not often seen, it is possible that sudden death could occur due to obstructions caused by hydrocephaly (water on the brain).


All information used in this blog was obtained through the following websites:
http://www.thedoctorsdoctor.com/diseases/pnet.htm
http://emedicine.medscape.com/article/1157440-overview

Yay! I actually figured this whole blogging thing out! Hopefully I did it right...
I should be posting an actual blog relative to our CT class soon. So until then...