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Hyposmia
Hyposmia, or microsmia, is a reduced ability to smell and to detect odors. A related condition is anosmia, in which no odors can be detected. Some of the causes of olfaction problems are allergies, nasal polyps, viral infections and head trauma. In 2012 an estimated 9.8 million people aged 40 and older in the United States had hyposmia and an additional 3.4 million had anosmia/severe hyposmia. Hyposmia might be a very early sign of Parkinson's disease.Factor, Stewart A., & Weiner, William J., eds. (2008). ''Parkinson's Disease: Diagnosis and Clinical Management'', 2nd ed., pp. 72-73. New York: Demos Medical Publishing. Hyposmia is also an early and almost universal finding in Alzheimer's disease and dementia with Lewy bodies. Lifelong hyposmia could be caused by or comorbid with Kallmann syndrome or autism. Along with other chemosensory disturbances, hyposmia can be a key indicator of COVID-19. Epidemiology The National Health and Nutrition Examination Survey ( NHANES) collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anosmia
Anosmia, also known as smell blindness, is the lack of ability to detect one or more smells. Anosmia may be temporary or permanent. It differs from hyposmia, which is a decreased sensitivity to some or all smells. Anosmia can be categorized into acquired anosmia and congenital anosmia. Acquired anosmia develops later in life due to various causes, such as upper respiratory infections, head trauma, or neurodegenerative diseases. In contrast, congenital anosmia is present from birth and is typically caused by genetic factors or developmental abnormalities of the olfactory system. While acquired anosmia may have potential treatments depending on the underlying cause, such as medications or surgery, congenital anosmia currently has no known cure, and management focuses on safety precautions and coping strategies. Anosmia can be due to a number of factors, including inflammation of the nasal mucosa, blockage of nasal passages, or destruction of temporal lobular tissue. Anosmia s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysosmia
Dysosmia is a disorder described as any qualitative alteration or distortion of the perception of smell. Qualitative alterations differ from quantitative alterations, which include anosmia and hyposmia. Dysosmia can be classified as either parosmia (also called troposmia) or phantosmia. Parosmia is a distortion in the perception of an odorant. Odorants smell different from what one remembers. Phantosmia is the perception of an odor when no odorant is present. The cause of dysosmia still remains a theory. It is typically considered a neurological disorder and clinical associations with the disorder have been made. Most cases are described as idiopathic and the main antecedents related to parosmia are URTIs, head trauma, and nasal and paranasal sinus disease. Dysosmia tends to go away on its own but there are options for treatment for patients that want immediate relief. Signs and symptoms Smell disorders can result in the inability to detect environmental dangers such as g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dementia With Lewy Bodies
Dementia with Lewy bodies (DLB) is a type of dementia characterized by changes in sleep, behavior change (individual), behavior, cognition, movement, and dysautonomia, regulation of automatic bodily functions. Unlike some other dementias, memory loss may not be an early symptom. The disease progressive disease, worsens over time and is usually diagnosed when cognitive impairment interferes with activities of daily living, normal daily functioning. Together with Parkinson's disease dementia, DLB is one of the two Lewy body dementias. It is a common form of dementia, but the prevalence is not known accurately and many diagnoses are missed. The disease was first described on autopsy by Kenji Kosaka (psychiatrist), Kenji Kosaka in 1976, and he named the condition several years later. REM sleep behavior disorder (RBD)—in which people lose the muscle paralysis (atonia) that normally occurs during Rapid eye movement sleep, REM sleep and act out their dreams—is a core feature. RBD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kallmann Syndrome
Kallmann syndrome (KS) is a hereditary, genetic disorder that prevents a person from starting or fully completing puberty. Kallmann syndrome is a form of a group of conditions termed hypogonadotropic hypogonadism. To distinguish it from other forms of hypogonadotropic hypogonadism, Kallmann syndrome has the additional symptom of a anosmia, total lack of sense of smell (anosmia) or a hyposmia, reduced sense of smell. If left untreated, people will have poorly defined secondary sexual characteristics, show signs of hypogonadism, almost invariably are infertile and are at increased risk of developing osteoporosis. A range of other physical symptoms affecting the face, hands and skeletal system can also occur. Cause & Diagnosis The underlying cause is due to the defective migration of gonadotropin-releasing hormone expressing neurons (GnRH neuron, GNRH neurons) from olfactory placode to hypothalamus, leading to congenital Gonadotropin-releasing hormone, GNRH deficiency. This leads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NHANES
The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews, physical examinations and laboratory tests. The NHANES interview includes demographic, socioeconomic, dietary, and health-related questions. The examination component consists of medical, dental, and physiological measurements, as well as laboratory tests administered by medical personnel. The National Health Survey Act was passed in 1956. This allowed legislative authorization to provide current statistical data on the amount, distribution, and effects on illness and disability in the United States. The first three national health examination surveys were conducted in the 1960s: # 1960-62—National Health Examination Survey I (NHES I); # 1963-65—National Health Examinatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperosmia
Hyperosmia is an increased olfactory acuity (heightened sense of smell), usually caused by a lower threshold for odor. This perceptual disorder arises when there is an abnormally increased signal at any point between the olfactory receptors and the olfactory cortex. The causes of hyperosmia may be genetic, hormonal, environmental or the result of benzodiazepine withdrawal syndrome. Causes Genetics A study by Menashe et al. has found that individuals with a single nucleotide polymorphism variant in the OR11H7P pseudogene have a lower receptor activation threshold for isovaleric acid. These individuals are hyperosmic for this single odorant. Another study by Keller et al. has found that people with the intact human odorant receptor OR7D4 are more sensitive to androstenone and androstadienone and thus find them unpleasant (individuals with the semi-functional OR7D4 have two non-synonymous single nucleotide polymorphisms in the OR7D4 pseudogene, resulting in two amino acid substi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prevalence
In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number of people found to have the condition with the total number of people studied and is usually expressed as a fraction, a percentage, or the number of cases per 10,000 or 100,000 people. Prevalence is most often used in questionnaire studies. Difference between prevalence and incidence Prevalence is the number of disease cases ''present ''in a particular population at a given time, whereas incidence is the number of new cases that ''develop ''during a specified time period. Prevalence answers "How many people have this disease right now?" or "How many people have had this disease during this time period?". Incidence answers "How many people acquired the disease uring a specified time period". However, mathematically, prevalence is propor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory
The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it occurs when an odor binds to a receptor within the nasal cavity, transmitting a signal through the olfactory system. Glomeruli aggregate signals from these receptors and transmit them to the olfactory bulb, where the sensory input will start to interact with parts of the brain responsible for smell identification, memory, and emotion. There are many different things which can interfere with a normal sense of smell, including damage to the nose or smell receptors, anosmia, upper respiratory infections, traumatic brain injury, and neurodegenerative disease. History of study Early scientific study of the sense of smell includes the extensive doctoral dissertation of Eleanor Gamble, published in 1898, which compared olfactory to othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemosensory
A chemoreceptor, also known as chemosensor, is a specialized sensory receptor which transduces a chemical substance (endogenous or induced) to generate a biological signal. This signal may be in the form of an action potential, if the chemoreceptor is a neuron, or in the form of a neurotransmitter that can activate a nerve fiber if the chemoreceptor is a specialized cell, such as taste receptors, or an internal peripheral chemoreceptor, such as the carotid bodies. In physiology, a chemoreceptor detects changes in the normal environment, such as an increase in blood levels of carbon dioxide (hypercapnia) or a decrease in blood levels of oxygen (hypoxia), and transmits that information to the central nervous system which engages body responses to restore homeostasis. In bacteria, chemoreceptors are essential in the mediation of chemotaxis. Cellular chemoreceptors In prokaryotes Bacteria utilize complex long helical proteins as chemoreceptors, permitting signals to travel long di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odor
An odor (American English) or odour ( Commonwealth English; see spelling differences) is a smell or a scent caused by one or more volatilized chemical compounds generally found in low concentrations that humans and many animals can perceive via their olfactory system. While ''smell'' can refer to pleasant and unpleasant odors, the terms ''scent'', ''aroma'', and ''fragrance'' are usually reserved for pleasant-smelling odors and are frequently used in the food and cosmetic industry to describe floral scents or to refer to perfumes. Odor physiology Sense of smell The perception of odors, or sense of smell, is mediated by the olfactory nerve. The olfactory receptor (OR) cells are neurons present in the olfactory epithelium, which is a small patch of tissue at the back of the nasal cavity. There are millions of olfactory receptor neurons that act as sensory signaling cells. Each neuron has cilia in direct contact with the air. Odorous molecules bind to receptor pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Health And Nutrition Examination Survey
The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews, physical examinations and laboratory tests. The NHANES interview includes demographic, socioeconomic, dietary, and health-related questions. The examination component consists of medical, dental, and physiological measurements, as well as laboratory tests administered by medical personnel. The National Health Survey Act was passed in 1956. This allowed legislative authorization to provide current statistical data on the amount, distribution, and effects on illness and disability in the United States. The first three national health examination surveys were conducted in the 1960s: # 1960-62—National Health Examination Survey I (NHES I); # 1963-65—National Health Examinati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
