|
Lilliputian Hallucinations
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, or viral encephalitis caused by Epstein–Barr virus 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 Though not agreed upon in literature, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Release Hallucinations
Visual release hallucinations, also known as Charles Bonnet syndrome or CBS, are a type of psychophysical visual disturbance in which a person with partial or severe blindness experiences visual hallucinations. First described by Charles Bonnet in 1760, the term ''Charles Bonnet syndrome'' was first introduced into English-speaking psychiatry in 1982. A related type of hallucination that also occurs with lack of visual input is the closed-eye hallucination. Signs and symptoms People with significant vision loss may have vivid recurrent visual hallucinations (fictive visual percepts). One characteristic of these hallucinations is that they usually are " lilliputian" (hallucinations in which the characters or objects are smaller than normal). Depending on the content, visual hallucinations can be classified as either simple or complex. Simple visual hallucinations are commonly characterized by shapes, photopsias, and grid-like patterns. Complex visual hallucinations consist of highl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 References Eye diseases {{eye-stub ... * Vision deficiencies and disorders References Eye diseases {{eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hallucination
A hallucination is a perception in the absence of an external stimulus that has the qualities of a real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space. Hallucination is a combination of 2 conscious states of brain wakefulness and REM sleep. They are distinguishable from several related phenomena, such as dreaming (REM sleep), which does not involve wakefulness; pseudohallucination, which does not mimic real perception, and is accurately perceived as unreal; illusion, which involves distorted or misinterpreted real perception; and mental imagery, which does not mimic real perception, and is under voluntary control. Hallucinations also differ from "delusional perceptions", in which a correctly sensed and interpreted stimulus (i.e., a real perception) is given some additional significance. Many hallucinations happen also during sleep paralyses. Hallucinations can occur in any sensory modality—visual, auditory, ... [...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] |
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] |
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 si ... [...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] |
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 L ... [...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 sensitivity to light, sound, or 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 : typically, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infectious Mononucleosis
Infectious mononucleosis (IM, mono), also known as glandular fever, is an infection usually caused by the Epstein–Barr virus (EBV). Most people are infected by the virus as children, when the disease produces few or no symptoms. In young adults, the disease often results in fever, sore throat, enlarged lymph nodes in the neck, and tiredness. Most people recover in two to four weeks; however, feeling tired may last for months. The liver or spleen may also become swollen, and in less than one percent of cases splenic rupture may occur. While usually caused by the Epstein–Barr virus, also known as human herpesvirus 4, which is a member of the herpesvirus family, a few other viruses may also cause the disease. It is primarily spread through saliva but can rarely be spread through semen or blood. Spread may occur by objects such as drinking glasses or toothbrushes or through a cough or sneeze. Those who are infected can spread the disease weeks before symptoms develop. Mono is p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epstein–Barr Virus
The Epstein–Barr virus (EBV), formally called ''Human gammaherpesvirus 4'', is one of the nine known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. EBV is a double-stranded DNA virus. It is best known as the cause of infectious mononucleosis ("mono" or "glandular fever"). It is also associated with various non-malignant, premalignant, and malignant Epstein–Barr virus-associated lymphoproliferative diseases such as Burkitt lymphoma, hemophagocytic lymphohistiocytosis, and Hodgkin's lymphoma; non-lymphoid malignancies such as gastric cancer and nasopharyngeal carcinoma; and conditions associated with human immunodeficiency virus such as hairy leukoplakia and central nervous system lymphomas. The virus is also associated with the childhood disorders of Alice in Wonderland syndrome and acute cerebellar ataxia and, by some evidence, higher risks of developing certain autoimmune diseases, especially dermatomyositis, systemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Encephalitis
Viral encephalitis is inflammation of the brain parenchyma, called encephalitis, by a virus. The different forms of viral encephalitis are called viral encephalitides. It is the most common type of encephalitis and often occurs with viral meningitis. Encephalitic viruses first cause infection and replicate outside of the central nervous system (CNS), most reaching the CNS through the circulatory system and a minority from nerve endings toward the CNS. Once in the brain, the virus and the host's inflammatory response disrupt neural function, leading to illness and complications, many of which frequently are neurological in nature, such as impaired motor skills and altered behavior. Viral encephalitis can be diagnosed based on the individual's symptoms, personal history, such as travel history, and different clinical tests such as histology, medical imaging, and lumbar punctures. A differential diagnosis can also be done to rule out other causes of the encephalitis. Many encephalitic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Metamorphopsia")
_1.jpg "Click for more on -> Migraine")
