Items tagged “reference needed”

Epiphora (plural: epiphoras) represents excessive tearing of the eye and is a common clinical presentation to ophthalmological practice. It is most frequently due to an obstruction of the nasolacrimal drainage apparatus. Less commonly, overproduction of tears may be responsible.  Epidemiology ...

Straight left heart border sign is a described finding on chest radiograph in cases of hemopericardium. It is a fairly specific (84%) sign of hemopericardium after a penetrating chest trauma, although sensitivity at 40% is relatively poor. Positive predictive value (PPV) was found to be 89% 1. ...

The iris (plural: irises or irides) is a pigmented muscular structure which modifies the amount of light entering the eye, by controlling the size of the pupil, its central aperture.  Summary location: between the anterior and posterior chambers of the globe function: controls the amoun...

Aniridia refers to either the clinical sign of a complete/partial absence of the iris, or more specifically to the disease entity classic aniridia. Rarely other genetic conditions may cause this sign. Epidemiology Classic aniridia is inherited as an autosomal dominant condition and is seen in ...

Posterior semicircular canal dehiscence syndrome (PSCD) is the presence of vestibuloauditory symptoms secondary to absence of the bony covering of the posterior semicircular canal (PSC). Epidemiology It is thought to be rare: in a case series of 112 patients with a high riding jugular bulb it ...

Multicentric ossification refers to normal, or variant of normal, ossification at more than one site within a single epiphysis or apophysis. It is important to be aware of common sites where multicentric ossification may occur, to avoid confusion with fracture, apophysitis and other entities. t...

CA 15-3 is a tumor marker used in monitoring breast cancer. The test detects levels of MUC-1, a mucin protein in the blood. MUC-1 is thought to be important in the invasiveness and metastasization of cancer cells. Physiology Mucin-1 is a normal epithelial cellular glycoprotein localized to the...

Gadolinium (chemical symbol Gd) is a metallic element that can be chelated into paramagnetic complexes for use as gadolinium contrast media. Chemistry Basic chemistry Gadolinium is a silvery rare earth metal, and a member of the lanthanides, with the atomic number 64 and an atomic weight of 1...

An accessory abductor digiti minimi (ADM) muscle is the most common accessory muscle of the hand and wrist, found in 24% of individuals on the hypothenar eminence. When present it is one of the intrinsic muscles of the hand. Summary origin: antebrachial fascia passing anteriorly to Guyon cana...

Hereditary spherocytosis (HS) (also known as Minkowski-Chauffard disease 1) is a group of hemolytic anemias due to a genetic abnormality of the erythrocyte cell membrane resulting in spherocytes. The clinical spectrum is broad, from a subclinical state to severe transfusion-dependant anemia. Ep...

Pyrexia (or fever) is a clinical sign, indicated by an abnormally elevated core body temperature, which is defined by several medical societies as ≥38.3°C (≥≈101°F). The temperature elevation may be persistent or episodic. If the body temperature is greater than 41.5°C - a rare phenomenon - it i...

Familial Mediterranean fever (FMF) (also known as recurrent polyserositis) is a genetic autoimmune condition that is notable for its spontaneous self-limiting acute episodes of fever and serositis, especially peritonitis and synovitis. Epidemiology Familial Mediterranean fever tends to be ethn...

Contrast media are a group of chemical agents developed to aid in the characterization of pathology by improving the contrast resolution of an imaging modality. Specific contrast media have been developed for every structural imaging modality, and every conceivable route of administration. Bari...

Tenesmus (also known as rectal tenesmus to differentiate from vesical tenesmus) is stated by patients as the unpleasant symptom that there remains something to evacuate from the rectum despite passing a stool. It is often - but not always - painful. Frequently there are actually no feces left in...

Left ventricular hypertrophy (LVH) is present when the left ventricular mass is increased. It is a common condition, typically due to systemic hypertension, and it increases with age, obesity and severity of hypertension. Epidemiology Studies have demonstrated a prevalence on echocardiography ...

Tendon tears and ruptures are common and sometimes disabling injuries. They can occur within the midsubstance or be an avulsion injury. Pathology The pathophysiology of tendon tears and ruptures is uncertain but is thought to be the end-point of tendinopathy in most cases. Location In theory...

Vitamin B5 deficiency, also known as hypovitaminosis B5, is extremely rare. Pantothenic acid (vitamin B5) is needed for the formation of coenzyme A, itself essential for the synthesis of acetylcholine and melatonin. Pantothenic acid is also required for normal functioning of the tricarboxylic ac...

Hysterectomy (plural: hysterectomies), the surgical resection of the uterus, is the most commonly performed gynecological procedure in the USA 3. It is usually performed electively. Epidemiology Approximately 600,000 hysterectomies are performed in the United States annually. After Cesarean se...

Chikungunya fever is caused by the chikungunya virus (CHIKV), and is characterized by a classic viral prodrome of fever, skin exanthem, malaise and arthralgia. Its most striking manifestation is a marked, often fairly debilitating arthritis. Clinical presentation fever arthralgia skin rash ...

Hemoglobin SC (HbSC) disease is a hemoglobinopathy, and a common variant of sickle cell disease (SCD). There is coinheritance of one HbS gene and one HbC gene, resulting in a milder phenotype than full-blown sickle cell disease. It most commonly manifests with a proliferative retinopathy. Painfu...