A relative afferent pupillary defect ( RAPD ), also known as a Marcus Gunn pupil (after Robert Marcus Gunn ), is a medical sign observed during the swinging-flashlight test whereupon the patient's pupils excessively dilate when a bright light is swung from the unaffected eye to the affected eye. The affected eye still senses the light and produces pupillary sphincter constriction to some degree, albeit reduced.
18-1338: APD is an initialism that may refer to: Medicine [ edit ] Afferent pupillary defect Acid Peptic Diseases Ambulatory Peritoneal Dialysis Pamidronic acid , also known as aminohydroxypropylidene bisphosphonate Antipsychotic Drugs Auditory processing disorder , difficulty in recognising sounds Antisocial personality disorder Avoidant personality disorder Antimicrobial Peptide Database Autoimmune progesterone dermatitis Law enforcement [ edit ] Airport Police Division , Singapore Akron Police Department Albany Police Department (Oregon) Albuquerque Police Department Amtrak Police Department Anaheim Police Department Anchorage Police Department Annapolis Police Department Antioch Police Department Apopka Police Department Arcadia Police Department Asheville Police Department Atlanta Police Department Aurora Police Department , Colorado Austin Police Department Other [ edit ] Air Passenger Duty , an excise duty levied on passengers flying from UK airports APD, NYSE stock symbol for Air Products & Chemicals APD, reporting mark for
36-506: A biopsy . A benign lesion that is evolving into a malignant lesion is called "premalignant". Cancerous lesions are sometimes classified by their growth kinetics, such as the Lodwick classification, which characterizes classes of bone lesions. Another type is an excitotoxic lesion, which can be caused by excitatory amino acids like kainic acid that kill neurons through overstimulation. Lesion size may be specified as gross , meaning it
54-416: A "skin lesion" or a " brain lesion " are named for the tissue where they are found. If there is an added significance to regions within the tissue—such as in neural injuries where different locations correspond to different neurological deficits—they are further classified by location. For example, a lesion in the central nervous system is called a central lesion, and a lesion in the peripheral nervous system
72-478: A French pacifist organisation Avalanche photodiode , a device for counting photons Apple Accessory Products Division , former name for The Keyboard Company, Inc. A retired US Navy hull classification symbol: High-speed transport (APD) American political development Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title APD . If an internal link led you here, you may wish to change
90-443: A light is alternately shone into the left and right eyes. A normal response would be equal constriction of both pupils, regardless of which eye the light is directed at. This indicates an intact direct and consensual pupillary light reflex . When the test is performed in an eye with an afferent pupillary defect, light directed in the affected eye will cause only mild constriction of both pupils (due to decreased response to light from
108-401: A normal brain in its "undamaged" parts. Sham lesion is the name given to a control procedure during a lesion experiment. In a sham lesion, an animal may be placed in a stereotaxic apparatus and electrodes inserted as in the experimental condition, but no current is passed, and therefore damage to the tissue should be minimal. Humans with brain lesions are often the subjects of research with
126-420: Is also common in retrobulbar optic neuritis due to multiple sclerosis but unreliable in bilateral optic neuritis. A total CN II lesion, in which the affected eye perceives no light, is very similar to a Marcus Gunn pupil; to distinguish them, in a CNII total lesion shining the light in the affected eye produces zero dilation nor constriction. Lesion A lesion is any damage or abnormal change in
144-440: Is called a peripheral lesion . A myocardial lesion results from damage to the heart muscle, and a coronary lesion is a subtype that describes a lesion in the coronary arteries . Coronary lesions are then further classified according to the side of the heart that is affected and the diameter of the artery in which they form. If a lesion is caused by a tumor , it can be classified as malignant or benign after analysis of
162-405: Is named after Scottish ophthalmologist Robert Marcus Gunn . A second common cause of Marcus Gunn pupil is a contralateral optic tract lesion, due to the different contributions of the intact nasal and temporal hemifields. The Marcus Gunn pupil is a relative afferent pupillary defect indicating a decreased pupillary response to light in the affected eye. In the swinging flashlight test ,
180-432: Is the case with many ulcers , which can have a bullseye or 'target' appearance. A coin lesion as seen in an X-ray has the appearance of a coin sitting on the patient's chest. Brain lesions may help researchers understand brain function. Research involving lesions relies on two assumptions: that brain damage can affect different aspects of cognition independently, and that a locally damaged brain functions identically to
198-419: Is visible to the unaided eye, or histologic , meaning a microscope is needed to see it. A space-occupying lesion , as the name suggests, has a recognizable volume and may impinge on nearby structures, whereas a non space-occupying lesion is simply a hole in the tissue, e.g. a small area of the brain that has turned to fluid following a stroke . Lesions may also be classified by the shape they form. This
SECTION 10
#1732772107652216-597: The Albany Port Railroad Alianza por la Democracia , a Dominican Republic political party Alpha Phi Delta , an American college fraternity APD, National Rail code for Appledore (Kent) railway station APD-40 , a stretch of highway near Cleveland, Tennessee A designation for highways that are part of the Appalachian Development Highway System (ADHS). Association de la paix par le droit ,
234-581: The tissue of an organism , usually caused by injury or diseases . Lesion is derived from the Latin laesio meaning "injury". Lesions may occur in plants as well as animals. There is no designated classification or naming convention for lesions. Since lesions can occur anywhere in the body and the definition of a lesion is so broad, the varieties of lesions are virtually endless. Generally, lesions may be classified by their patterns, their sizes, their locations, or their causes. They can also be named after
252-417: The afferent defect), while light in the unaffected eye will cause a normal constriction of both pupils (due to an intact efferent path, and an intact consensual pupillary reflex). Thus, light shone in the affected eye will produce less pupillary constriction than light shone in the unaffected eye. Anisocoria is absent. A Marcus Gunn pupil is seen, among other conditions, in unilateral optic neuritis . It
270-445: The goal of establishing the function of the area where their lesion occurred. A drawback to the use of human subjects is the difficulty in finding subjects who have a lesion to the area the researcher wishes to study. As such, transcranial magnetic stimulation is often used in cognition and neuroscience-related tests to imitate the effect. Using animal subjects gives researchers the ability to study lesions in specific body parts of
288-430: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=APD&oldid=1187970149 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Afferent pupillary defect Depending on severity, different symptoms may appear during
306-426: The person who discovered them. For example, Ghon lesions , which are found in the lungs of those with tuberculosis , are named after the lesion's discoverer, Anton Ghon. The characteristic skin lesions of a varicella zoster virus infection are called chickenpox . Lesions of the teeth are usually called dental caries , or "cavities". Lesions are often classified by their tissue types or locations. For example,
324-458: The swinging flash light test: Mild RAPD initially presents as a weak pupil constriction, after which dilation occurs. When RAPD is moderate, pupil size initially remains same, after which it dilates. When RAPD is severe, the pupil dilates quickly. The most common cause of Marcus Gunn pupil is a lesion of the optic nerve (between the retina and the optic chiasm ) due to glaucoma, a severe retinal disease, or due to multiple sclerosis . It
#651348