| acute aortic dissection | <cardiology> A condition in which a weakened portion of the thoracic aorta begins to tear along the longitudinal axis of the vessel. Symptoms include sudden, severe chest pain that may radiate to the back accompanied by nausea, sweating and difficulty breathing. A common risk factor for this event is atherosclerotic vascular disease and-or hypertension. Advanced cases of syphilis (syphilitic aortitis) can also result in acute thoracic dissection as a complication of infection with Treponema pallidum. (27 Sep 1997) |
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| acute appendicitis | Acute inflammation of the appendix, usually due to bacterial infection, which may be precipitated by obstruction of the lumen by a fecalith; symptoms of periumbilical colicky pain and vomiting are followed by fever, leukocytosis, persistent pain, and signs of peritoneal inflammation in the right lower quadrant of the abdomen; perforation or abscess formation is a frequent complication. (05 Mar 2000) |
| acute ascending paralysis | A paralysis of rapid course beginning in the legs and involving progressively the trunk, arms, and neck, ending sometimes in death in from one to three weeks. Synonym: ascending paralysis. (05 Mar 2000) |
| acute ataxia | Generalised ataxia of abrupt onset, most often caused by drug intoxications, poisonings, or vestibular neuronitis. (05 Mar 2000) |
| acute atrophic paralysis | Inflammation of the anterior cornua of the spinal cord; an acute infectious disease caused by the poliomyelitis virus and marked by fever, pains, and gastroenteric disturbances, followed by a flaccid paralysis of one or more muscular groups, and later by atrophy. Synonym: acute atrophic paralysis, myogenic paralysis. (05 Mar 2000) |
| acute bacterial endocarditis | A type of bacterial endocarditis caused by pyogenic organisms such as haemolytic streptococci or staphylococci. (05 Mar 2000) |
| acute brachial radiculitis | A neurological disorder, of unknown cause, characterised by the sudden onset of severe pain, usually about the shoulder and often beginning at night, soon followed by weakness and wasting of various forequarter muscles, particularly shoulder girdle muscles; both sporadic and familial in occurrence with the former much more common; often preceded by some antecedent event, such as an upper respiratory infection, hospitalization, vaccination, or non-specific trauma; usually attributed to a brachial plexus lesion, because the nerve fibres involed are most often derived from the upper trunk, but actually multiple proximal mononeuropathies. Synonym: acute brachial radiculitis, brachial plexitis, brachial plexus neuropathy, Parsonage-Turner syndrome, shoulder-girdle syndrome. (05 Mar 2000) |
| acute brain syndrome | <syndrome> A condition of severe confusion or rapid change in brain function. This often occurs as the result of a mental illness or physical illness. Symptoms include lethargy, agitation, confusion, disorientation and delirium. (27 Sep 1997) |
| acute bulbar poliomyelitis | Poliomyelitis virus infection affecting nerve cells in the medulla oblongata and producing paralysis of the lower motor cranial nerves. (05 Mar 2000) |
| acute catarrhal conjunctivitis | An obsolete term for conjunctivitis with marked hyperaemia and mucopurulent discharge, with a tendency toward spontaneous recovery. Synonym: mucopurulent conjunctivitis. (05 Mar 2000) |
| acute cellular rejection | Graft rejection which usually begins within 10 days after a graft has been transplanted into a genetically dissimilar host. Lesions at the site of the graft characteristically are infiltrated with large numbers of lymphocytes and macrophages which cause tissue damage. See: primary rejection. Synonym: acute rejection. (05 Mar 2000) |
| acute chalazion | An acute purulent infection of a meibomian (tarsal) gland. Synonym: acute chalazion, hordeolum meibomianum, meibomian sty. (05 Mar 2000) |
| acute chemical pneumonitis | <chest medicine> Inflammation of the lungs which occurs secondary to exposure to a chemical, organic dust, fungus or mould. Chronic exposure can lead to chronic lung changes evident on chest X-ray. Symptoms include cough, fever, shortness of breath and wheezing. See: bird-handler's disease. (27 Sep 1997) |
| acute cholecystitis | <radiology> 80-95% secondary to cystic duct obstruction by gallstone, 5-6th decade; 75% female ultrasound (sensitivity 85-95%; specificity 64-100%): gall bladder wall thickening (greater than3mm), halo sign = gall bladder wall lucency (in 70%), gall bladder hydrops = AP diameter more than 5cm, sonographic Murphy sign (85%), pericholecystic fluid, hepatobiliary scan (95% accuracy): nonvisualization of gallbladder complications: gangrene, irregular wall (ulcers, intraluminal hemmorhage, necrosis), hyperechoic foci within gall bladder wall (microabscesses in Rokitansky-Aschoff sinuses), perforation (5-10%): most commonly in fundus, empyema: gravity dependent debris (12 Dec 1998) |
| acute chorea | A postinfectious chorea appearing several months after a streptococcal infection with subsequent rheumatic fever. The chorea typically involves the distal limbs and is associated with hypotonia and emotional lability. Improvement occurs over weeks or months and exacerbations occur without associated infection recurrence. Synonym: acute chorea, chorea minor, chorea, juvenile chorea, rheumatic chorea, Sydenham's disease. (05 Mar 2000) |