View source for Eponyms (A-B)

==A==
===Adson's Sign===
Decreased radial pulse with neck turn and breath holding. Associated with [[thoracic outlet syndrome]]

===Abernethy malformation===
Congenital anomaly of the splanchnic vasculature, arises from defects in vitelline vein formation; in type 1, portal vein completely diverted into IVC and complete absence of formation of intrahepatic portal vein; in type 2, portal venous system is formed, but there is an abnormal communication with systemic veins, usually IVC; associated with hepatic encephalopathy and hepatopulmonary syndrome; more common in dogs, particularly Yorkshire terriers.

===Achenbach's syndrome===
Rare entity of spontaneous or mechanically-induced hematomas on the volar aspect of fingers associated with burning pain and swelling of the digits.

===[[Addison's disease]]===
{{Addison's background}}

===Adie's pupil===
Tonic pupil, larger than contralateral unaffected pupil, reacts sluggishly to changes in illumination; see also Holmes-Adie syndrome; seen in young women and has no neurologic significance.

===Adler Sign===
For distinguishing appendicitis from adnexal or uterine pain (TOA vs Appendicitis). If the point of maximal tenderness shifts medially with repositioning on the left lateral side, etiology generally gynecologic.

===Adson's Sign===
In thoracic outlet syndrome, decrease in ipsilateral radial pulse and/or presence of subclavian bruit while patient extending neck maximally, rotating head towards side being tested, and holding breath.

===Andermann syndrome===
Familial progressive sensorimotor neuropathy with agenesis of the corpus callosum, mental retardation; found in high frequency in Quebec; associated with mutation in SLC12A6, a K-Cl transporter.

===Andersen's syndrome===
Periodic muscle paralysis, arrhythmias, short stature, macrocephaly, hypertelorism, brachydactyly, tapering fingers; from mutation in KCNJ2 which encodes a potassium channel Kir2.1; also with dental abnormalities, incomplete secondary dentition, cleft palate, first described in 1971; also long QT syndrome 7 (LQT7).
===Andersen disease===
Type IV glycogen storage disease (or amylopectinosis), from branching enzyme deficiency, presents with cirrhosis with hepatosplenomegaly and failure to thrive in the first 18 months of life.

===Andersson lesion===
Discovertebral lesion, seen in ankylosing spondylitis.

===Artery of Adamkiewicz===
Artery that when severed, can lead to anterior spinal syndrome; can be severed in abdominal aortic aneurysm repair.

===Adamson's fringe===
In tinea capitis, the location of the terminal tuft of hyphae; weakest point of hair located just about Adamson's fringe.
===Ahumada-del Castillo syndrome===
Galactorrhea-amenorrhea not associated with pregnancy.

===Aicardi syndrome===
Partial or complete agenesis of corpus callosum, infantile spasms, mental retardation, lacunae of the retina; occurs only in females; likely X-linked dominant with lethality in males; described in 1965.

===Ainhum Disease===
Autoamputation of a digit, usually of the fifth toe from a constricting scar in the form of a band or groove; usually from trauma acquired from walking barefoot; felt to be more common in tropics in patients of African descent; "ainhum" means "fissure" in one of the indigenous language in Brazil.

===Alagille Syndrome===
Inherited cholestatic syndrome, associated with biliary hypoplasia (ductopenia), vertebral anomalies, prominent forehead, deep-set eyes, peripheral pulmonic stenosis. Autosomal dominant, associated with mutation in JAG1 or NOTCH2.

===Albers-Schönberg Disease===
Osteopetrosis or marble bone disease, autosomal dominant. Characterized by sclerosis, mainly involving the spline, pelvis, and skull base, and paradoxical fragility of bones. Due to mutation in CLCN7 gene.

===Alberts Test===
For diagnosing hemineglect; patient presented with multiple lines on a page and asked to cross them out; if >70% of crossed out lines are ipsilateral to motor deficit, hemineglect is diagnosed<ref>Albert, M. A simple test of visual neglect. Neurology 1973; 23:658-64</ref>

===Albrights Hereditary Osteodystrophy===
Pseudohypoparathyroidism type 1a, from lack of renal responsiveness to parathyroid hormone, resulting in low serum calcium, high serum phosphate, and appropriately high serum parathyroid hormone. Associated with short stature, characteristically shortened fourth and fifth metacarpals, and rounded facies.

===Alder-Reilly Anomaly===
Large, dark, pink-purple granules in cytoplasm of neutrophils; autosomal recessive trait resulting in abnormal granule development in neutrophils resembling severe toxic granulation. Associated with mucopolysaccharidoses (e.g. Hurler's syndrome, etc.).

===Alexanders Disease===
Leukodystrophy-like neurodegenerative disease presenting in infancy or childhood; characterized by Rosenthal fibers. Presents with megalencephaly followed by progressive spasticity and dementia. From mutation in GFAP.

===Alexander's Law===
Peripheral vestibular nystagmus increases in intensity when the gaze is in the direction of the fast phase, and decreases in intensity when the gaze is away from the fast phase.

===Allen's Sign===
In pulmonary embolism, fever, tachycardia, and tachypnea; present in only 23% of cases.

===Allen's Test===
For demonstrating patent ulnar artery and an intact superficial palmar arch, patient's hand is initially held high while fist is clenched and both radial and ulnar arteries are compressed, hand then lowered and fist is opened; after ulnar pressure released, color should return to the hand within 6 seconds.

===Allgrove syndrome===
Triad of achalasia, adrenal insufficiency and alacrima (also known as AAA syndrome). Autosomal recessive, described in 1978, associated with mutation in gene encoding aladin.

===Allis sign===
In congenital hip dislocation, difference in knee height when child is supine with knees flexed and feet are flat on examination table.

===[[Alport syndrome]]===
Hereditary nephritis associated with end stage renal disease accompanied by deafness and various eye disorders, including lens dislocation, posterior cataracts, and corneal dystrophy; a few families have large platelets (20-25 fL), thrombocytopenia, and leukocyte inclusions which resemble May-Hegglin anomaly. Associated with mutations in collagen IV.

===Alström's syndrome===
Autosomal recessive disorder with obesity, childhood blindness due to retinal degeneration, nerve deafness, vasopressin-resistant diabetes insipidus, and in males, hypogonadism with high plasma gonadotropin levels (end organ resistance to hormones), also baldness, hyperuricemia, hypertriglyceridemia, aminoaciduria.

===Amadori product===
Products of early non enzymatic glycosylation of proteins.

===Ambesh maneuver===
Internal jugular vein occlusion test for diagnosis of misplaced subclavian vein catheter into the internal jugular vein. Apply external pressure to the internal jugular vein and observe for change in central venous pressure and wave form.<ref>Ambesh S. et al. Internal Jugular Vein Occlusion Test for Rapid Diagnosis of Misplaced Subclavian Vein Catheter into the Internal
Jugular Vein. Anesthesiology 2001; 95:1377–9 [http://theddx.org/papers/IJVocclusion-1%20Anesthesiology.pdf PDF]</ref>

===Amyand's hernia===
Appendix contained within an incarcerated inguinal hernia (n.b. first appendectomy done by Claudius Amyand).

===Angelman syndrome===
Happy puppet" syndrome; disorder with severe developmental delay, frequent laughing, easily excitable personality; from maternal deletion of 15q11-13; associated with mutation in maternally-imprinted ATP10C, a putative aminophospholipid translocase.

===Angel's sign===
Performing an otoscopic exam while patient is blowing against a pinched nose; increases sensitivity of otoscopy for the detection of a perforated tympanic membrane by demonstrating fluid or pus in the external canal; described in 1994.

===Anitschkow myocytes===
In [[rheumatic fever]], large mesenchymal cells in myocardial lesion.

===Anterior chiasmal syndrome of Traquair===
From anterior chiasmal lesion, a junctional scotoma due to compression of the ipsilateral optic nerve.

===Antley-Bixler syndrome===
Trapezoidocephaly-synostosis syndrome; characterized by midface hypoplasia, humeroradial synostosis, bowing of femora, fractures; associated with inactivating mutations in FGFR2; occasionally associated with ambiguous genitalia; see also Apert syndrome which is also due to mutations in FGFR2.

===Anton's syndrome===
Denial of cortical blindness; a form of anosognosia.

===Apert syndrome===
Autosomal dominant disorder from mutation in FGFR2 characterized by craniosynostosis, mid-facial malformations, symmetric bony syndactyly of hands and feet, and varying degrees of mental retardation, from missense mutations in the fibroblast growth-factor-receptor 2 (FGFR2) genes; see also Antley-Bixler syndrome which is also due to mutations in FGFR2.

===[[Apgar score]]===
Described in 1953, five parameters assessed: heart rate, respiratory effort, muscle tone, reflex irritability, and color; score 7 or greater said to be indicator of good health; 5 minute score most reliable; 5 min score of 0-3, mortality 244/1000 v. score of 7-10, mortality 0.2/1000 (N Engl J Med 2001;344:467). Described by Virginia Apgar (1909-1974).

===Apley grind test===
For meniscal tears, flex patient's leg to 90 degrees, then grind the tibial condyles against the femoral condyles with rotation motion in the varus and then valgus positions.

===Apley scratch test===
Asking patient to scratch the back from above or bottom, looking for furthest point reached (T4-T5 former, T7-T8 latter normal); if patient cannot reach, infraspinatus/teres minor tendonitis tear or subscapularis tendonitis/tear respectively.

===Apley's law===
In pediatrics, the farther a chronically recurrent abdominal pain is from the umbilicus, the greater the likelihood of an organic cause for the pain.

===Apt test===
Test which differentiates fetal from maternal hemoglobin in infant's gastric contents, vomitus, or stool.

===Arantius duct===
Ductus venosus, described by Giulio Cesare Aranzio.

===Archibald's sign===
In pseudohypoparathyroidism of Albright's hereditary osteodystrophy, characteristic shortening of the fourth and fifth digits as dimpling over the knuckles of a clenched fist.

===Argyll Robertson pupils===
Small irregular pupils, usually but not always caused by CNS [[syphilis]], they "accommodate, but do not react." Absence of miotic reaction to light, both direct and consensual, with preservation of a miotic reaction to near stimulus; lesion in tectum of midbrain. Named after Douglas M. C. L. Argyll Robertson.

===Arnold-Chiari malformation===
Downward displacement of the cerebellar tonsils and medulla through the foramen magnum, results in pressure atrophy of displaced brain tissue, hydrocephalus from obstruction of the CSF outflow tract. It is almost always characterized by the presence of a thoracolumbar meningomyelocele.

===Arnold's nerve===
Auricular branch of vagus nerve supplying posterior and inferior meatal skin of ear; stimulation can elicit cough reflex.

===Arnold's reflex===
Ear cough reflex mediated by Arnold's nerve.

===Arthus reaction===
Localized area of tissue necrosis resulting from acute immune complex vasculitis; type III hypersensitivity.

===Asboe-Hansen sign===
In pemphigus vulgaris, extension of intact blister when pressure is applied to roof of blister. See also Nikolsky's sign.

===Aschoff body===
Pathognomonic finding in rheumatic carditis: an area of local fibrinoid necrosis surrounded by inflammatory cells including lymphocytes, plasma cells, and macrophages that later resolve to fibrous scar tissue.

===Asherman's syndrome===
Intrauterine synechiae, may occur after curettage of the uterus, presenting as amenorrhea.

===Asherson's syndrome===
Catastrophic antiphospholipid antibody syndrome.

===Ashman's phenomenon===
Relationship of aberrancy to changes in the preceding cycle length; may persist for several cycles, usually exhibits right bundle branch morphology.

===Askin's tumor===
Malignant small cell tumor of the thoracopulmonary region; member of Ewing's sarcoma family or primitive neuroectodermal tumors.

===Asperger's disorder===
An autistic spectrum disorder with severe and sustained impairment in social interactions and the development of restricted, repetitive patterns of behavior, interests, and activities, but intellectually normal and no language delays, but with abnormalities of spoken language.

===Auenbrugger's sign===
Epigastric bulge due to a massive pericardial effusion.

===Auer rods===
May be present in [[acute myeloid leukemia]] or refractory anemia with excess blasts; granules form elongated needles, granules are all azurophilic, contain peroxidase; fused lysosomes.

===Auerbach's plexus===
Myenteric plexus, between the longitudinal and circular layers of muscle; provides motor innervation to the two muscle layers and secretomotor innervation to the mucosa.

===Auspitz's sign===
In psoriasis, sign is positive when slight scratching or curetting of a scaly lesion reveals punctate bleeding points within the lesion. Sign suggests psoriasis, but is not specific.

===Austin Flint murmur===
Diastolic rumble in aortic regurgitation heard at cardiac apex, thought to be due to aortic jet impinging on the mitral valve, causing vibrations and also from simultaneous diastolic filling of the left ventricle from the left atrium and aorta closing the mitral valve in diastole, producing physiologic stenosis; named after Austin Flint (1812-1886).

===Australia antigen===
Hepatitis B surface antigen; initially described in the serum of an Australian aborigine.

===Austrian triad===
Clinical triad of pneumococcal pneumonia, meningitis, and endocarditis (classically aortic valve endocarditis associated with aortic regurgitation); described by Robert Austrian.

==B==
===Babinski sign===
Normally plantar response where toes flex in response to sole of foot being stroked; upgoing toes are an upper motor sign that indicates dysfunction of fibers within the pyramidal system; described in 1896 by Babinski, student of Charcot.

===Bachmann's bundle===
Anterior internodal tract in atrial conduction system.

===Bainbridge reflex===
Compensatory increase in heart rate caused by a rise in right atrial pressure.

===[[Baker's Cyst]]===
A popliteal cyst

===Balint's syndrome===
Optic ataxia (inability to visually guide limb movements), ocular ataxia (inability to direct eyes to a precise point in the visual field), inability to enumerate objects in a picture or extract meaning from a picture, and inability to avoid objects in one's path, simultanagnosia (can only process one object at a time), from infarction in unilateral or bilateral visual association area due to watershed stroke between distal PCA and MCA.

===Balkan nephropathy===
Degenerative interstitial nephropathy seen in Balkan areas (tributaries of Danube River), with tubular proteinuria, glycosuria, renal tubular acidosis, azotemia, associated with increased risk of upper tract transitional cell carcinoma. Hypothesized to be from chronic exposure to dietary aristolochic acid from Aristolochia clematitis, a plant native to endemic areas.

===Ballance's sign===
Tender mass in the left upper quadrant due to a spleen hematoma.

===Ball's disease===
Intracerebral [[leukostasis]], a potentially fatal complication of [[acute leukemia]] (especially AML) when peripheral blast cell count >100,000/uL; leukemic cells capable of invading through endothelium and causing hemorrhage into brain. Condition not generally seen with CLL or CML.

===Baló's disease===
Variant of [[multiple sclerosis]], see concentric rings of demyelination separated by bands of preserved myelin.

===Baltic myoclonus===
See Unverricht-Lundborg disease. 

===Bamboo spine===
Radiographic appearance of spine in [[ankylosing spondylitis]]. 

===Bancroft's sign===
In [[deep venous thrombosis]], compression of calf forward against tibia causing more pain than horizontal compression when gastrocnemius muscle is lifted; also referred to as Moses's sign. 

===Bang's disease===
[[Brucellosis]]. Described by Danish veterinarian and bacteriologist, Bernhard Bang (1848-1932). Also known as Malta fever. 

===Bannayan-Ruvalcaba-Riley syndrome===
See Bannayan-Zonana syndrome. 

===Bannayan-Zonana syndrome===
Hamartoma syndrome characterized by macrocephaly, multiple lipomas, and hemangiomas, speckled penis; associated with with germ line PTEN mutations; also known as Bannayan-Ruvalcaba-Riley syndrome. 

===Bannwarth's syndrome===
In early disseminated [[Lyme disease]], triad of lymphocytic meningitis, cranial nerve palsies (especially VII nerve which may be bilateral), and radiculoneuritis. 

===Banti's syndrome===
Splenomegaly, hypersplenism, and portal hypertension, noncirrhotic, arises after subclinical occlusion of the portal vein, usually years after occlusive event. 

===Bantu siderosis===
Unusual form of iron overloading resembling hereditary hemochromatosis in South African blacks ingesting large quantities of alcoholic beverages fermented in iron utensils. 

===Bárány test===
See Dix-Hallpike test. 

===Bardet-Biedl syndrome===
Mental retardation, pigmentary retinopathy, polydactyly, obesity, and hypogenitalism; genetically heterogeneous disorder with linkage to 7 loci; has been previously called Laurence-Moon-Bardet-Biedl syndrome in the past. 

===Barlow's disease===
Mitral valve prolapse. 

===Barlow's maneuver===
For congenital hip dislocation, patient placed in supine position and attempt made to push femurs posteriorly with knees at 90 degrees/hip flexed and hip will dislocate. 

===Barr body===
Condensed, inactive X-chromosome in females; dense, stainable structure. 

===Barraquer-Simons syndrome===
Acquired partial lipodystrophy; presents usually around 8-10, preceded generally by an acute viral infection; spares legs and hips; 1/3 of patients develop membranoproliferative glomerulonephritis; associated with accelerated complement activation and a serum immunoglobulin G, called C3 nephritic factor that are felt to cause lysis of adipose tissue. 

===Barré-Liéou syndrome===
Cervicosympathetic syndrome, characterized by neck pain and dizziness due to arthritic or traumatic damage to the cervical spine. 

===Barrett's esophagus===
Esophageal strictures and epithelial metaplasia from squamous epithelium to a specialized columnar epithelium with intestinal metaplasia in 10% of severe GERD. Associated with predisposition to esophageal adenocarcinoma. 

===[[Bartholin's]] gland===
Paired glands located near vaginal opening; maintain moisture of vaginal vestibular surfaces; can form abscesses or cysts; homologous to Cowper's gland; described by Danish anatomist Caspar Bartholin in 1677. 

===Barth's syndrome===
Infantile X-linked dilated cardiomyopathy, short stature, myopathy, cyclic neutropenia; from mutation in G4.5 which encodes for tafazzin (a putative acyl transferase that has been associated with altered metabolism of the mitochondrial phospholipid cardiolipin). 

===[[Barton's fracture]]===
Intra-articular fracture of dorsal margin of distal radius; extends into radio-carpal joint. 

===Bartter's syndrome===
Hypokalemic, hypochloremic metabolic alkalosis with normal or low blood pressure despite increased renin and aldosterone levels and hyperplasia of juxtaglomerular apparatus due to mutations affecting diuretic-sensitive sodium-transport proteins. 

===Bassen-Kornzweig syndrome===
Congenital abetalipoproteinemia. 

===Bat wing edema===
[[Pulmonary edema]] in perihilar distribution in approximately 5% of cases . 

===Bateman's senile purpura===
Purpura following trauma to severely sun-damaged skin of the dorsal forearm of elderly persons; months may be required for resolution of pigmentation from hemorrhage. 

===Batista procedure===
For treatment of heart failure, removal of portion of left ventricular free wall, i.e. partial left ventriculectomy. 

===Batson's plexus===
Portal vertebral venous communications, may be mechanism for colon cancer metastases seen in sacrum or vertebral bodies. 

===Batten's disease===
Neuronal ceroid lipofuscinosis, type 3, juvenile form. A group of conditions characterized by mental impairment, worsening seizures, and progressive loss of sight and motor skills related to buildup of lipopigments. 

===Battle's sign===
Ecchymoses over the mastoid process in basilar skull fractures, generally occurring approximately 48 hours after event. 

===Bazex's syndrome===
Acrokeratosis paraneoplastica, consists of erythematous to violaceous psoriaform plaques occurring predominantly in acral areas; associated with Hodgkin's disease and squamous cell carcinomas of digestive tract. 

===Bazin's disease===
Nodular vasculitis or erythema induratum, a form of panniculitis classically associated with tuberculosis characterized histologically by caseation necrosis; described by Bazin in 1861. 

===BCG===
Bacille bilié de Calmette-Guérin, an attenuated strain of Mycobacterium bovis bacille Calmette-Guérin. Leon A. Calmette, French bacteriologist, 1863-1933; Camille Guérin, French bacteriologist, 1872-1961. 

===Beau's lines===
Horizontal depressions across nail plate seen as nail grows out, caused by a transient arrest in nail growth, can occur during acute stress (e.g., high fever, circulatory shock, myocardial infarction, pulmonary embolism). See also Pohl-Pinkus constriction involving hair. 

===Bechterew's disease===
[[Ankylosing spondylitis]]. 

===Becker's muscular dystrophy===
X-linked, normal levels of dystrophin but function altered, average onset 11 y.o., age at death 42 y.o., CK elevated; see also Duchenne's muscular dystrophy. 

===Becker's sign===
In aortic regurgitation, visible pulsations of the retinal arterioles. 

===Beck's triad===
In [[cardiac tamponade]], distended neck veins, distant heart sounds, hypotension, i.e. rising venous pressure, falling arterial pressure, and decreased heart sounds. Described by Claude S. Beck, thoracic surgeon, in 1935. 

===Beckwith-Wiedemann syndrome===
Exomphalos, macroglossia, gigantism; associated with neonatal hypoglycemia. 

===Beevor's sign===
Upward movement of umbilicus when abdominal wall contracts seen in lesions of T9-T10 which paralyze lower but spare upper abdominal muscles. 

===[[Behçet's disease]]===
Triad of aphthous ulcers, genital ulcerations, and ocular inflammation (posterior uveitis). Associated with erythema nodosum, cutaneous pustular vasculitis, also synovitis, CNS vasculitis involving brain stem, thrombophlebitis, and positive pathergy response. Described by Turkish dermatologist Behçet in 1937; also known as Silk Road disease due to clustering of cases along the Silk Road. 

===Bellini duct===
Tn the kidney, central tube in the medulla where the tubes of each renal pyramid converges. 

===[[Bell's palsy]]===
Peripheral seventh nerve palsy; seen as a complication in diabetes, tumors, sarcoidosis, HIV, and Lyme disease. 

===Bell's phenomenon===
Physiological upward rotation of the eyeball triggered by contraction of the ipsilateral orbicularis muscle with resulting closure of the eyelid. 

===Bence Jones proteins===
Free immunoglobulin light chains seen in plasma cell dyscrasias (e.g. [[multiple myeloma]], AL-amyloidosis, light-chain deposition disease, Waldenström's macroglobulinemia, MGUS, heavy-chain disease (mu) (rare), lymphoproliferative disease (rare), rifampin therapy (rare)). These light chains are filtered by glomerulus and then reabsorbed by tubular cells; proteins are toxic to tubule cells; described by Henry Bence Jones. Note, there is no hyphen in "Bence Jones." 

===Benedikt's syndrome===
Clinical picture from paramedian midbrain infarction from occlusion of the paramedian penetrating branches of the basilar artery affecting the third nerve root fiber, red nucleus, cerebral peduncle resulting in ipsilateral medial rectus palsy with a fixed dilated pupil and contralateral tremor, chorea, and athetosis. 

===[[Bennett's fracture]]===
Fracture of the base of the first metacarpal with involvement of carpometacarpal joint. 

===Bentall procedure===
For treating ascending aortic aneurysms, composite prosthetic graft consisting of prosthetic aortic valve sewn onto end of graft. 

===Berardinelli-Seip syndrome===
Congenital generalized lipodystrophy, apparent at birth, infants look very muscular due to absence of fat, associated with diabetes, hepatomegaly, acanthosis nigricans, enlarged external genitalia, and increased rate of skeletal growth. 

===Berger's disease===
IgA nephropathy; end stage renal disease develops in 15% of cases at 10 years and 20% at 20 years; treated with steroids in certain instances. 

===Bergman minimal model===
Determinants of glucose disposal: phi-1 (acute insulin secretion), phi-2 (sustained insulin secretion), Si (insulin sensitivity), Sg (glucose sensitivity). 

===Bergmann gliosis===
In ethanol abuse, proliferation of astrocytes adjacent to lost Purkinje cells between depleted granular cell and molecular layer of cerebellum. 

===Bergman's triad===
Seen with [[fat embolism syndrome]]: (1) mental status changes; (2) petechiae (often in the axilla/thorax); (3) dyspnea. 

===Bernard-Soulier disease===
Inherited disorder of platelet function where there is absence of Gp Ib/IX, the von Willebrand receptor, characterized by giant platelets and greater than expected bleeding for the degree of thrombocytopenia. 

===Bernheim effect===
In aortic stenosis, right ventricular failure preceding left ventricular failure from hypertrophied ventricular septum bulging into and encroaching on right ventricular filling. 

===Bernheim effect, reverse===
In pulmonary embolism, right ventricular failure causing septum to bulge into and compromise left ventricular filling. 

===Bernstein test===
To test for gastroesophageal reflux disorder, acid perfusion test of esophagus with 0.1 N HCl and see if reproduces chest pain; limited sensitivity and specificity though. 

===Berry's ligament===
Thickened fascia next to the trachea; binds thyroid gland to cricoid cartilage; recurrent laryngeal nerve tends to run underneath it. 

===Berry's sign===
In malignant thyromegaly, absence of carotid pulsation from tumor encasing carotid and muffling pulsations. 

===Bertin, renal columns of===
The spaces between adjacent renal pyramids where cortical tissue extends into. 

===Best disease===
Vitelliform macular dystrophy type 2 (VMD2), characterized by gradual loss of visual acuity starting in their teenage years; accumulation of lipofuscin in retinal pigment epithelium; markedly abnormal electro-oculogram (EOG) in all stages of progression and in phenotypically normal carriers; autosomal dominant, from mutation in VMD2 gene; first described in 1905. 

===Betz cells===
Large pyramidal cells in layer 5 of primary motor cortex largest neurons in mammalian central nervous system; 30-40,000 Betz cells in precentral gyrus in one side of the brain. 

===Bezold-Jarisch reflex===
Activation of receptors in the atria, great veins, and left ventricle causing increased parasympathetic tone and decreased sympathetic activity leading to a combination of hypotension and bradycardia with a sudden increase in coronary flow. 

===Bezold's abscess===
Abscess formed below the pinna or behind the sternocleidomastoid muscle often due to acute [[Mastoiditis|mastoiditis]].<ref>Jeffrey H. Spiegel et al. Contemporary Presentation and Management of a Spectrum of Mastoid Abscesses. June 1998. 108(6) pages 822–828</ref>

===Bickers-Adams syndrome===
Sex-linked hydrocephalus, aqueductal stenosis, mental deficiency, and flexion deformities and spasticity of the extremities. Most common inherited forms of inherited hydrocephalus. X-linked (Xq28), due to mutation in L1CAM. 

===Bickerstaff's encephalitis===
Brain stem encephalitis. Has features of Miller Fisher syndrome, but with encephalopathy and hyperreflexia. Associated with anti-GQ1b antibodies; can be te treated with IVIG and plasma exchange. 

===Bielschowsky's tilt test===
In trochlear nerve palsy (which paralyzes the superior oblique muscle), elevation in the affected eye is greatest when the head is tilted toward the side of the involved eye and abolished by tilt in the opposite direction. 

===Bier block===
Regional anesthesia of an extremity by placing a tourniquet and then infusing local anesthetic into a vein. Described by August Karl Gustav Bier (1861-1949). 

===Biette's collarette===
In syphilis, a thin white ring of scales on the surface of a lesion. 

===Billroth I===
Antrectomy with gastroduodenostomy. After Austrian surgeon, Billroth (1829-1894). 

===Billroth II===
Antrectomy with gastrojejunostomy. After Austrian surgeon, Billroth (1829-1894). 

===Billroth's cords===
Splenic cords found in the red pulp between the sinusoids, consisting mainly of fibrils and connective tissue cells. 

===Bing-Horton syndrome===
Erythroprosopalgia, attacks of facial pain associated with marked reddening of the ipsilateral half of the face associated with tearing and watery discharge from the nose, occurs during sleep and is of brief duration, believed to be due to irritaiton in greater petrosal nerve. 

===Bing's sign===
Extensor plantar response by pricking the dorsal surface of the big toe with a pin suggesting upper motor neuron defect. 

===Binswanger's disease===
Subcortical arteriosclerotic encephalopathy, associated with hypertension; characterized by multiple lacunar infarcts and progressive demyelination limited to the subcortical area with characteristic sparing of cortex. 

===Biot's breathing===
Succession of hyperpnea/hyperventilations and apneas (seen in increased ICP, drug-induced respiratory depression, brain damage, usually medullary level), but lacks typical crescendo-decrescendo pattern, abrupt beginning, and regularity of Cheyne-Stokes breathing. 

===Birbeck's granules===
Also known as Langerhans's granules, a small tennis racket-shaped membrane-bound granule with characteristic cross-striated internal ultrastructure seen in Langerhans cell histiocytosis. 

===Birt-Hogg-Dube syndrome===
Genodermatosis characterized by hair follicle hamartomas, renal cell cancer, and spontaneous pneumothorax; caused by mutation in gene encoding folliculin; also associated with trichodiscomas and acrochordons. 

===Bishop's score===
Scoring system for determining whether or not induction of labor will be successful, based on 5 criteria (scored from 0-3): position, cervical consistency, degree of effacement, dilatation, and station; score >9 suggests that induction will be successful. 

===Bitot's spots===
In vitamin A deficiency, small, circumscribed, lusterless, grayish white, foamy, greasy, triangular deposits on the bulbar conjunctiva adjacent to the cornea in the area of the palpebral fissure of both eyes. 

===Bjork-Shiley valve===
Single tilting disk prosthetic valve, production stopped in 1986; large valves removed from market in October 1985 because of strut fracture. 

===Björnstad syndrome===
Autosomal recessive disorder characterized by sensorineural hearing loss and pili torti (twisted hairs, where hair shafts are flattened at irregular intervals and twisted 180 degrees from the normal axis, making the hair extremely brittle); associated with mutation in BCS1L, a chaperone protein. 

===Blalock-Taussig shunt===
For palliation and treatment of severely cyanotic heart diseases such as tetralogy of Fallot or pulmonary valve atresia: direct end-to-side subclavian artery to pulmonary artery anastomosis on side opposite to arch of aorta (classic); alternatively graft placed between subclavian artery and pulmonary artery (modified). 

===Bland-White-Garland syndrome===
Anomalous origin of the left coronary artery from the pulmonary artery; presents in infancy with myocardial ischemia and CHF; though delayed presentations also occur including sudden death in adulthood. 

===Blaschkow, lines of===
Patterning of a variety of linear nevi as well as linear patterning of commonly acquired diseases such as psoriasis, scleroderma, and lichen planus, including V shape over the upper spine, S shape of the abdomen, inverted U shape from the breast area, and perpendicular lines down lower extremities; cannot be explained by distribution of cutaneous nerve, lines of cleavage, nor blood vessels or lymphatics; first described in 1901. 

===Blau's syndrome===
Granulomatous synovitis, non granulomatous uveitis, cranial neuropathies; resembles childhood sarcoidosis; no lung involvement. Associated with mutations in NOD2/CARD15 gene; first described in 1985. 

===Blomstrand dysplasia===
Rare lethal disorder characterized by an increase in bone density and advanced skeletal maturation from inactivating mutation in PTHR-1 gene (see also Jansen metaphyseal chondrodysplasia where there is an activating mutation). 

===Bloom's syndrome===
Severe immunodeficiency, growth retardation, progeria, and predisposition to several types of cancers associated with hypersensitivity to a variety of DNA-damaging agents. Associated with mutation in DNA helicase RecQ protein-like-3. 

===Blount's disease===
Idiopathic varus bowing of tibia. 

===Blumberg sign===
Rebound tenderness seen in peritonitis. 

===Blumer shelf===
Metastasis from a primary site high up in the peritoneal cavity, e.g. from stomach, felt through the anterior rectal wall as a hard shelf in the rectovesical or rectouterine pouch (pouch of Douglas). 

===B-Lynch suture===
For treating post-partum hemorrhage, a heavy suture to compress an atonic uterus. Described by Christopher B-Lynch (born Christopher Balogun-Lynch). 

===Boas's sign===
Right subscapular pain due to cholelithiasis, <7% sensitive. 

===Bobble-head syndrome===
In children with progressive [[hydrocephalus]], rapid, rhythmic bobbing of the head. 

===Bochdalek hernia===
A form of congenital diaphragmatic hernia, through the posterior diaphragm, usually on the left. Compare to Morgagni's hernia. 

===Bockhart's impetigo===
Follicular impetigo. 

===[[Boerhaave syndrome]]===
Pressure rupture of the esophagus; can give rise to Hamman's sign. 

===Bogota bag===
Temporary abdominal closure with filleted intravenous bag. Use described in Bogota, Colombia. 

===Bogros space===
Space bounded by the peritoneum above and the fascia transversalis below where the lower part of the external ilica artery can be seen without cutting the peritoneum; also called retroinguinal space. 

===Bohr effect===
Fall in pH leading to decrease in oxygen affinity of hemoglobin. 

===Bohr equation===
Vd/Vt, for determining ratio of physiologic dead space. 

===Bombay phenotype===
Blood type O when A or B blood type expected; these individuals are recessive for H allele and do not make H antigen; H antigen required as precursor for A or B antigen to be expressed. First described in Bombay; explains a child with O blood type when a parent is e.g. AB blood type; rare phenotype, more common in consanguineous matings. 

===Bonnet-Dechaume-Blanc syndrome===
See Wyburn-Mason syndrome. 

===Bonnet's sign===
Banking of veins distal to AV crossings (grade 3) in hypertensive retinopathy; compare with Salus's sign and Gunn's sign. 

===Bonnevie-Ullrich syndrome===
Skeletal and soft tissue abnormalities (e.g., lymphedema of hands and feet, nail dystrophy, skin laxity), short stature, webbed neck. Older, European term for Turner's syndrome. 

===Borchardt's triad===
In gastric volvulus, triad of abdominal pain or distension, vomiting without emesis, and inability to pass a nasogastric tube. 

===Bordet-Gengou medium===
For identifying Bordetella pertussis, medium contains high percentage of rabbit blood (20-30%) to inactivate inhibitors in blood; also has potato and glycerol. 

===Bornholm disease===
Coxsackie virus infection leading to pleurodynia, fever, cough, sore throat, myalgias in shoulder, chest, and abdomen. Bornholm is a Danish island in Baltic sea. 

===Boston sign===
In thyrotoxicosis, jerking of the lagging lid. 

===Bouchard's nodes===
Bony spurs at proximal interphalangeal joint in osteoarthritis. 

===Bourneville's disease===
Tuberous sclerosis. 

===Bouveret syndrome===
Gastric outlet obstruction from gallstone impaction of the duodenum. 

===Bovie===
Apparatus for delivering high-frequency electrical current to tissues in order to cut and/or coagulate. Developed by William Bovie (1882-1958). First used by Harvey Cushing in 1926. 

===Bowditch staircase===
Increased heart rate increases the strength of contraction in a stepwise fashion as the intracellular calcium increases over several beats. 

===Bowen's disease===
Squamous carcinoma in situ, seen generally on sun-exposed areas. 

===Bowman's capsule===
Double-walled structure that surrounds the glomerulus. 

===[[Boxer's fracture]]===
Fracture of the metacarpal neck, classically of small finger. 

===[[Boutonniere deformity]]===
Caused by injury to Extensor III zone over PIP joint

===Bozzolo sign===
In aortic regurgitation, pulsatile nasal mucosa. 

===Braak stage===
Pathologic staging system for the neurofibrillary degeneration seen in Alzheimer's disease, first described in 1991. 

===Bradbury-Eggleston syndrome===
Pure autonomic dysfunction characterized by low circulating catecholamines. 

===Brainerd diarrhea===
Acute onset of watery diarrhea lasting four weeks or longer, can occur in outbreaks or sporadically; named after first outbreak in 1983 in Brainerd, Minnesota. 

===Brandt-Daroff exercises===
Home treatment maneuvers for benign positional vertigo done three sets per day for two weeks (Arch Otolaryngol 1980; 106:484-5). See also Epley maneuver. 

===Branham's sign===
Bradycardia after compression of AV fistula. 

===Braxton-Hicks contractions===
Painless contractions of the uterine muscles during the second and third trimesters of pregnancy. 

===Brechenmacher fibers===
Tracts which connect the atrium to the His bundle. 

===Brenner tumor===
Benign ovarian tumor composed of epithelial cells in clusters within a deep fibrous stroma. 

===[[Brewerton view]]===
Hand X-Ray view to evaluate subtle carpometacarpal fractures and arthritic pathology

===Bricker procedure===
Creation of a urinary diversion by removing a piece of ileum, connecting the ureters to it, and then creating a stoma through the abdominal wall. 

===Bright's disease===
Acute [[glomerulonephritis]]. 

===Brill-Symmer's disease===
Nodular [[lymphoma]]. 

===Brill-Zinser disease===
Recrudescent form of epidemic typhus (Rickettsiae prowazekii); occurs 10-50 years after primary infection; presents abruptly with chills, fevers, headache, malaise; rash after 4-6 days after onset of symptoms. 

===Briquet's syndrome===
[[Somatic symptom disorder]]. 

===Broca's aphasia===
Expressive aphasia, where speech is non-fluent and difficult to initiate, associated with damage to Broca's area. Because Broca's area is near motor cortex and underlying internal capsule, associated with a right hemiparesis and homonymous hemianopsia. 

===Broca's area===
Left frontal speech area, important for articulating speech; see Broca's aphasia. 

===Brockenbrough sign===
In hypertrophic cardiomyopathy, increase in murmur after a premature ventricular contraction, related to increase in LV systolic pressure, increase in systolic gradient between LV and aorta and consequent decrease in systolic pressure and pulse pressure. 

===Brock's syndrome===
Right middle lobe atelectasis; more common in children with history of asthma or atopy. 

===Brodel's line===
Bloodless plane in the kidney between the anterior and posterior branches of the renal artery. 

===Brodie's abscess===
Small, intraosseus [[abscess]] that frequently involves the cortex and is walled off by reactive bone. 

===Brodie-Trendelenburg test===
For testing great saphenous vein and branches communicating with deep femoral vein; limb is elevated until drained of venous blood and then tourniquet is applied; normally arterial flow from below fills veins in about 35 s; however faster filling indicates incompetence of communicating vein. 

===Brodman area===
Neuro anatomical classification of the cortex based on its cyto architecture into 52 areas; e.g. precentral gyrus Brodman 4, striate cortex Brodman 17. 

===Brompton's cocktail===
An elixir made from morphine (or heroin), cocaine, ethanol, and occasionally chlorpromazine. Named after the Royal Brompton Hospital in London. Initial formulation (which included chloroform) developed in the 1920s. 

===Brooke ileostomy===
Proctocolectomy with permanent ileostomy; a procedure used to treat ulcerative colitis, etc. 

===Brooke-Spiegler syndrome===
"Turban tumor", autosomal dominant disorder associated with cylindromas, trichoepitheliomas, and spiradenomas mainly in head and neck region appearing in early adulthood. Associated with mutations in CYLD gene. 

===[[Broselow tape]]===
Tool for estimating weight and endotracheal tube size in pediatric population; developed by Broselow, an emergency physician in Hickory, North Carolina in the mid 1980s and by Luten. 

===Brown's syndrome===
In [[rheumatoid arthritis]], vertical diplopia, clicking sensation when looking up and medially, and an apparent inferior oblique palsy, apparently from stenosing tenosynovitis of the superior oblique tendon and sheath; also congenital form. 

===[[Brown-Séquard syndrome]]===
Loss of tactile sense, vibration sense, and limb position sense on the ipsilateral side and loss of pain and temperature sense on the contralateral side; due to lesion involving only one side of the spinal cord. 

===Bruce protocol===
Multistage exercise treadmill test (seven 3 minute stages), described in 1963; developed by Robert A. Bruce (1916-2004), the "father of exercise cardiology." 

===Bruch's membrane===
Basal layer of the choroid between the choriocapillaris and the retinal pigment cell layer; deposits in this membrane in macular degeneration are known as drusen. 

===Bruck syndrome===
Skeletal disorder resembling osteogenesis imperfecta with severe bone fragility and deformity; associated with congenital joint contractures; due to deficiency in telopeptide lysyl hydroxylase. 

===Brudzinski sign===
After flexing the neck, flexion of hips and knees in response. Suggests meningeal inflammation as seen in [[meningitis]]. 

===Brueghel syndrome===
Dystonia of the motor trigeminal nerve producing a widely opened mouth, named after painting by Flemish painter Brueghel (Neurol 1996;46:1768). 

===[[Brugada syndrome]]===
Defect in an ion channel gene resulting in abnormal electrophysiologic activity in the right ventricle and characterized by (1) ST segment elevation in V1-V3, (2) right bundle branch block, (3) sudden cardiac death, (4) grossly normal heart; accounts for 40-60% of idiopathic ventricular fibrillation. 

===Brunner's glands===
In duodenum, submucosal mucous glands that secrete bicarbonate, glycoproteins, and pepsinogen II, virtually indistinguishable from pyloric mucous glands. 

===Brushfield's spots===
In Down's syndrome, small white spots on the periphery of the iris. 

===Bruton's tyrosine kinase===
Mutation in Bruton's tyrosine kinase associated with X-linked agammaglobulinemia (XLA also associated with defect in intact membrane-bound m chain). Btk is essential for B cell development; found onlyin B cells. 

===[[Budd-Chiari syndrome]]===
Occlusion of the hepatic vein (e.g. by thrombosis), associated with polycythemia vera, pregnancy, postpartum state, oral contraceptives, paroxysmal nocturnal hemoglobinuria, and intra-abdominal cancers, particularly hepatocellular carcinoma. 

===[[Buerger disease]]===
Thromboangiitis obliterans, a nonatherosclerotic segmental inflammatory disease that most commonly affects the small and medium-sized arteries, veins, and nerves of the arms and legs. Acute phase reactants normal; strong association with tobacco use. 

===Buerger's sign===
In peripheral vascular disease, red foot becomes pale with elevation. 

===Bunina bodies===
Intraneuronal inclusions felt to be pathognomonic for motor neuron disease. 

===Burgdorf's reaction===
Acral erythema involving palms and soles after chemotherapy, originally reported in patients with acute myelogenous leukemia receiving cytarabine. 

===Burkitt's lymphoma===
Highly aggressive B-cell [[lymphoma]] with tumor manifesting at extranodal sites (with endemic African variety, characteristically facial tumors); one of the fastest growing tumors in humans with doubling time 24-48 hours. Associated with translocation of c-myc gene on chr 8 with IgH locus (chr 14), kappa (chr 2), or lambda light-chain (chr 22) locus; associated with EBV infection in African variety. Named after Dennis Burkitt, British surgeon (1911-1993). 

===Burnett's syndrome===
Far-advanced [[milk-alkali syndrome]], due to long-standing calcium and alkali ingestion; severe hypercalcemia, irreversible renal failure, and phosphate retention, may be accompanied by ectopic calcification; see also Cope's syndrome. 

===Burow's solution===
Aluminum acetate in water, invented in mid-1800s by ophthalmologist Karl Burow (also known by its tradename Domeboro). Used as an astringent for treating rashes, e.g. from poison ivy. 

==[[Burr hole]]===
Procedure to relieve intracranial pressure in rapidly-expanding epidural or subdural hematoma

===Burton's line===
Line at the interface of teeth and gums seen in chronic lead toxicity; from reaction of circulating lead with sulfur ions released by oral microbial activity. 

===Buruli ulcer===
Caused by Mycobacterium ulcerans; painless nodule to large, undermined ulcerative lesions that heal spontaneously but slowly. Named after Buruli region of Nile River. 

===Buschke, scleredema of===
Uncommon dermatosis characterized by thickened, indurated skin associated with diabetes, sometimes with erythema; also known as scleredema diabeticorum. 

===Buschke-Löwenstein tumor===
Verrucous carcinoma involving penile glans and prepuce, associated with HPV. 

===Buschke-Ollendorff syndrome===
Disseminated connective tissue nevi of elastic type and osteopoikilosis; associated with mutation in LEMD3 gene. 

===Byler's disease===
Progressive familial intrahepatic cholestasis. From impaired biliary secretion of both bile acids and phosphatidylcholine, leads to death from liver failure before adolescence. From mutation in ATP8B1. Autosomal recessive.

==See Also==
*[[Eponyms (C-E)]]
*[[Eponyms (F-L)]]
*[[Eponyms (M-P)]]
*[[Eponyms (Q-S)]]
*[[Eponyms (T-Z)]]

==References==
<references/>

[[Category:Misc/General]]