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Dysmetropsia
Alice in Wonderland syndrome (AIWS), also known as Todd's syndrome or dysmetropsia, is a neuropsychological condition that causes a distortion of perception. People may experience distortions in visual perception of objects, such as appearing smaller (micropsia) or larger (macropsia), or appearing to be closer (pelopsia) or farther (teleopsia) than they actually are. Distortion may also occur for senses other than vision. The cause of Alice in Wonderland syndrome is currently unknown, but it has often been associated with migraines, Head Trauma, head trauma, or viral encephalitis caused by Epstein–Barr virus Infectious mononucleosis, infection. It is also theorized that it can be caused by abnormal amounts of electrical activity, resulting in abnormal blood flow in those parts of the brain which process visual perception and texture. Although there are cases of Alice in Wonderland syndrome in both adolescents and adults, it is most commonly seen in children. Classification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macropsia
Macropsia is a neurological condition affecting human visual perception, in which objects within an affected section of the visual field appear larger than normal, causing the person to feel smaller than they actually are. Macropsia, along with its opposite condition, micropsia, can be categorized under dysmetropsia. Macropsia is related to other conditions dealing with visual perception, such as aniseikonia and Alice in Wonderland Syndrome ( AIWS, also known as Todd's syndrome). Macropsia has a wide range of causes, from prescription and illicit drugs, to migraines and (rarely) complex partial epilepsy, and to different retinal conditions, such as epiretinal membrane. Physiologically, retinal macropsia results from the compression of cones in the eye. It is the compression of receptor distribution that results in greater stimulation and thus a larger perceived image of an object. Signs and symptoms The most obvious symptom of macropsia is the presence of exceptionally enlarged ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macropsia
Macropsia is a neurological condition affecting human visual perception, in which objects within an affected section of the visual field appear larger than normal, causing the person to feel smaller than they actually are. Macropsia, along with its opposite condition, micropsia, can be categorized under dysmetropsia. Macropsia is related to other conditions dealing with visual perception, such as aniseikonia and Alice in Wonderland Syndrome ( AIWS, also known as Todd's syndrome). Macropsia has a wide range of causes, from prescription and illicit drugs, to migraines and (rarely) complex partial epilepsy, and to different retinal conditions, such as epiretinal membrane. Physiologically, retinal macropsia results from the compression of cones in the eye. It is the compression of receptor distribution that results in greater stimulation and thus a larger perceived image of an object. Signs and symptoms The most obvious symptom of macropsia is the presence of exceptionally enlarged ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micropsia
Micropsia is a condition affecting human visual perception in which objects are perceived to be smaller than they actually are. Micropsia can be caused by optical factors (such as wearing glasses), by distortion of images in the eye (such as optically, via swelling of the cornea or from changes in the shape of the retina such as from retinal edema, macular degeneration, or central serous retinopathy), by changes in the brain (such as from traumatic brain injury, epilepsy, migraines, prescription drugs, and illicit drugs), and from psychological factors. Dissociation (neuropsychology), Dissociative phenomena are linked with micropsia, which may be the result of Lateralization of brain function, brain-lateralization disturbance. Micropsia is also commonly reported when the eyes are fixating at (Vergence#Convergence, convergence), or focusing at (accommodation), a distance closer than that of the object in accord with Emmert's law. Specific types of micropsia include hemimicropsia, a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleopsia
Teleopsia is a vision perception disorder, in which objects appear much farther away than they are. Teleopsia is a disorder associated with dysmetropsia. See also *Pelopsia Pelopsia is a vision perception disorder in which objects appear nearer than they actually are. Pelopsia can be caused by psychoneurotic phenomena, changes in atmospheric clarity, or sometimes by wearing a corrective lens. See also *Teleopsia Tele ... References Eye diseases {{eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micropsia
Micropsia is a condition affecting human visual perception in which objects are perceived to be smaller than they actually are. Micropsia can be caused by optical factors (such as wearing glasses), by distortion of images in the eye (such as optically, via swelling of the cornea or from changes in the shape of the retina such as from retinal edema, macular degeneration, or central serous retinopathy), by changes in the brain (such as from traumatic brain injury, epilepsy, migraines, prescription drugs, and illicit drugs), and from psychological factors. Dissociation (neuropsychology), Dissociative phenomena are linked with micropsia, which may be the result of Lateralization of brain function, brain-lateralization disturbance. Micropsia is also commonly reported when the eyes are fixating at (Vergence#Convergence, convergence), or focusing at (accommodation), a distance closer than that of the object in accord with Emmert's law. Specific types of micropsia include hemimicropsia, a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleopsia
Teleopsia is a vision perception disorder, in which objects appear much farther away than they are. Teleopsia is a disorder associated with dysmetropsia. See also *Pelopsia Pelopsia is a vision perception disorder in which objects appear nearer than they actually are. Pelopsia can be caused by psychoneurotic phenomena, changes in atmospheric clarity, or sometimes by wearing a corrective lens. See also *Teleopsia Tele ... References Eye diseases {{eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amnesia
Amnesia is a deficit in memory caused by brain damage or disease,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be caused temporarily by the use of various sedatives and hypnotic drugs. The memory can be either wholly or partially lost due to the extent of damage that was caused. There are two main types of amnesia: retrograde amnesia and anterograde amnesia. Retrograde amnesia is the inability to retrieve information that was acquired before a particular date, usually the date of an accident or operation. In some cases the memory loss can extend back decades, while in others the person may lose only a few months of memory. Anterograde amnesia is the inability to transfer new information from the short-term store into the long-term store. People with anterograde amnesia cannot remember things for long periods of time. These two types are not mutually exclusive; both can occur simu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatosensory System
In physiology, the somatosensory system is the network of neural structures in the brain and body that produce the perception of touch (haptic perception), as well as temperature (thermoception), body position (proprioception), and pain. It is a subset of the sensory nervous system, which also represents visual, auditory, olfactory, and gustatory stimuli. Somatosensation begins when mechano- and thermosensitive structures in the skin or internal organs sense physical stimuli such as pressure on the skin (see mechanotransduction, nociception). Activation of these structures, or receptors, leads to activation of peripheral sensory neurons that convey signals to the spinal cord as patterns of action potentials. Sensory information is then processed locally in the spinal cord to drive reflexes, and is also conveyed to the brain for conscious perception of touch and proprioception. Note, somatosensory information from the face and head enters the brain through periphera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical complaint, affecting 20-30% of persons. Dizziness is broken down into 4 main subtypes: vertigo (~25-50%), disequilibrium (less than ~15%), presyncope (less than ~15%), and nonspecific dizziness (~10%). * Vertigo is the sensation of spinning or having one's surroundings spin about them. Many people find vertigo very disturbing and often report associated nausea and vomiting. * Presyncope describes lightheadedness or feeling faint; the name relates to syncope, which is actually fainting. * Disequilibrium is the sensation of being off balance and is most often characterized by frequent falls in a specific direction. This condition is not often associated with nausea or vomiting. * Non-specific dizziness may be psychiatric in origin. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphopsia
Metamorphopsia (from , ) is a type of distorted vision in which a grid of straight lines appears wavy and parts of the grid may appear blank. People can first notice they suffer with the condition when looking at mini-blinds in their home. For example, straight lines might be wavy or bendy. Things may appear closer or further than they are. Initially characterized in the 1800s, metamorphopsia was described as one of the primary and most notable indications of myopic and senile maculopathies. Metamorphopsia can present itself as unbalanced vision, resulting from small unintentional movements of the eye as it tries to stabilize the field of vision. Metamorphopsia can also lead to the misrepresentation of an object’s size or shape. It is mainly associated with macular degeneration, particularly age-related macular degeneration with choroidal neovascularization. 80%)—deposition of yellowish extracellular material in and between Bruch's membrane and retinal pigment epithelium (“ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 definitions of nausea were proposed in a 2011 book on the topic. Nausea is a non-specific symptom, which means that it has many possible causes. Some common causes of nausea are gastroenteritis and other gastrointestinal disorders, food poisoning, motion sickness, dizziness, migraine, fainting, low blood sugar, anxiety, and lack of sleep. Nausea is a side effect of many medications including chemotherapy, or morning sickness in early pregnancy. Nausea may also be caused by disgust and depression. Medications taken to prevent and treat nausea and vomiting are called antiemetics. The most commonly prescribed antiemetics in the US are promethazine, metoclopramide, and the newer ondansetron. The word nausea is from Lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Migraine
Migraine (, ) is a common neurological disorder characterized by recurrent headaches. Typically, the associated headache affects one side of the head, is pulsating in nature, may be moderate to severe in intensity, and could last from a few hours to three days. Non-headache symptoms may include nausea, vomiting, and photophobia, sensitivity to light, hyperacusis, sound, or Osmophobia, smell. The pain is generally made worse by physical activity during an attack,as PDF although regular physical exercise may prevent future attacks. Up to one-third of people affected have Aura (symptom), aura: typically, it is a short period of visual disturbance that signals that the headache will soon occur. Occasionally, aura can occur with little or no headache follow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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