|
Craniopharyngioma
A craniopharyngioma is a rare type of brain tumor derived from pituitary gland embryonic tissue that occurs most commonly in children, but also affects adults. It may present at any age, even in the prenatal and neonatal periods, but peak incidence rates are childhood-onset at 5–14 years and adult-onset at 50–74 years. People may present with bitemporal inferior quadrantanopia leading to bitemporal hemianopsia, as the tumor may compress the optic chiasm. It has a point prevalence around two per 1,000,000. Craniopharyngiomas are distinct from Rathke's cleft tumours and intrasellar arachnoid cysts. Symptoms and signs Craniopharyngiomas are almost always benign. However, as with many brain tumors, their treatment can be difficult, and significant morbidities are associated with both the tumor and treatment. * Headache (obstructive hydrocephalus) * Hypersomnia * Myxedema * Postsurgical weight gain * Polydipsia * Polyuria (diabetes insipidus) * Vision loss (bitemporal hemianopia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rathke's Pouch
In embryogenesis, Rathke's pouch is an evagination at the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the anterior pituitary (adenohypophysis), a part of the endocrine system. Development Rathke's pouch, and therefore the anterior pituitary, is derived from ectoderm. The pouch eventually loses its connection with the pharynx giving rise to the anterior pituitary. The anterior wall of Rathke's pouch proliferates, filling most of the pouch to form '' pars distalis'' and '' pars tuberalis''. The posterior wall forms '' pars intermedia''. In some organisms, the proliferating anterior wall does not fully occupy Rathke's pouch, leaving a remnant (Rathke's cleft) between the ''pars distalis'' and ''pars intermedia''. Clinical significance Rathke's pouch may develop benign cysts. Craniopharyngioma is a neoplasm which can arise from the epithelium within the cleft. Eponym It is named for Martin Rathke Martin Heinrich Rathke (25 August 17 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prolactin
Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pituitary gland in response to eating, mating, estrogen treatment, ovulation and nursing. It is secreted heavily in pulses in between these events. Prolactin plays an essential role in metabolism, regulation of the immune system and pancreatic development. Discovered in non-human animals around 1930 by Oscar Riddle and confirmed in humans in 1970 by Henry Friesen, prolactin is a peptide hormone, encoded by the ''PRL'' gene. In mammals, prolactin is associated with milk production; in fish it is thought to be related to the control of water and salt balance. Prolactin also acts in a cytokine-like manner and as an important regulator of the immune system. It has important cell cycle-related functions as a growth-, differentiating- and anti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pituitary Insufficiency
Hypopituitarism is the decreased (''hypo'') secretion of one or more of the eight hormones normally produced by the pituitary gland at the base of the Human brain, brain. If there is decreased secretion of one specific pituitary hormone, the condition is known as selective hypopituitarism. If there is decreased secretion of most or all pituitary hormones, the term panhypopituitarism (''pan'' meaning "all") is used. The signs and symptoms of hypopituitarism vary, depending on which hormones are undersecreted and on the underlying cause of the abnormality. The diagnosis of hypopituitarism is made by blood tests, but often medical imaging, specific scans and other investigations are needed to find the underlying cause, such as tumors of the pituitary, and the ideal treatment. Most hormones controlled by the secretions of the pituitary can be replaced by tablets or injections. Hypopituitarism is a rare disease, but may be significantly underdiagnosed in people with previous traumatic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potentially m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitemporal Hemianopia
Bitemporal hemianopsia, is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field. It is usually associated with lesions of the optic chiasm, the area where the optic nerves from the right and left eyes cross near the pituitary gland. Causes In bitemporal hemianopsia, vision is missing in the outer (temporal or lateral) half of both the right and left visual fields. Information from the temporal visual field falls on the nasal (medial) retina. The nasal retina is responsible for carrying the information along the optic nerve, and crosses to the other side at the optic chiasm. When there is compression at optic chiasm, the visual impulse from both nasal retina are affected, leading to inability to view the temporal, or peripheral, vision. This phenomenon is known as bitemporal hemianopsia. Knowing the neurocircuitry of visual signal flow through the optic tract is very important in understanding bitem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cystic
A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble); however, the distinguishing aspect of a cyst is that the cells forming the "shell" of such a sac are distinctly abnormal (in both appearance and behaviour) when compared with all surrounding cells for that given location. A cyst may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst may resolve on its own. When a cyst fails to resolve, it may need to be removed surgically, but that would depend upon its type and location. Cancer-related cysts are formed as a defense mechanism for the body following the development of mutations that lead to an uncontrolled cellular division. Once that mutation has occurred, the affected cells divide incessantly and become cancerous, formi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suprasellar
The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometric analysis#Cephalometric_landmarks, cephalometric landmark. The pituitary gland or hypophysis is located within the most inferior aspect of the sella turcica, the hypophyseal fossa (anatomy), fossa. Structure The sella turcica is located in the sphenoid bone behind the chiasmatic groove and the tuberculum sellae. It belongs to the middle cranial fossa. The sella turcica's most inferior portion is known as the hypophyseal fossa (the "seat of the saddle"), and contains the pituitary gland (hypophysis). In front of the hypophyseal fossa is the tuberculum sellae. Completing the formation of the saddle posteriorly is the dorsum sellae, which is continuous with the Clivus (anatomy), clivus, inferoposteriorly. The dorsum sellae is terminated lateral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolyte Imbalance
Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function, fluid balance, oxygen delivery, acid–base balance and much more. Electrolyte imbalances can develop by consuming too little or too much electrolyte as well as excreting too little or too much electrolyte. Examples of electrolytes include: calcium, chloride, magnesium, phosphate, potassium, and sodium. Electrolyte disturbances are involved in many disease processes, and are an important part of patient management in medicine. The causes, severity, treatment, and outcomes of these disturbances can differ greatly depending on the implicated electrolyte. The most serious electrolyte disturbances involve abnormalities in the levels of sodium, potassium or calcium. Other electrolyte imbalances are less common and often occur in conjunction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Blood-pressure
Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the diastolic blood pressure (the bottom number), which are the maximum and minimum blood pressures, respectively. A systolic blood pressure of less than 90 millimeters of mercury (mmHg) or diastolic of less than 60 mmHg is generally considered to be hypotension. Different numbers apply to children. However, in practice, blood pressure is considered too low only if noticeable symptoms are present. Symptoms include dizziness or lightheadedness, confusion, feeling tired, weakness, headache, blurred vision, nausea, neck or back pain, an irregular heartbeat or feeling that the heart is skipping beats or fluttering, or fainting. Hypotension is the opposite of hypertension, which is high blood pressure. It is best understood as a physiological stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatigue (medical)
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve after rest or sleep, or occurs independently of physical or mental exertion, it may be a symptom of a medical condition that may become severe or progressive. Fatigue can be a feature of a mental disorder such as depression; may be associated with conditions of chronic pain such as fibromyalgia; it may also feature in conditions of chronic low-level inflammation, and be a disease-related symptom in many other conditions. Fatigue often has no known cause, and is recognised as being very complex in nature. Fatigability describes a susceptibility to fatigue. Physical fatigue results from muscle fatigue brought about by intense physical activity. Mental fatigue results from prolonged periods of cognitive activity which impairs cognitive abil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabetes Insipidus
Diabetes insipidus (DI), recently renamed to Arginine Vasopressin Deficiency (AVP-D) and Arginine Vasopressin Resistance (AVP-R), is a condition characterized by large amounts of dilute urine and increased thirst. The amount of urine produced can be nearly 20 liters per day. Reduction of fluid has little effect on the concentration of the urine. Complications may include dehydration or seizures. There are four types of DI, each with a different set of causes. Central DI (CDI) is due to a lack of the hormone vasopressin (antidiuretic hormone). This can be due to injury to the hypothalamus or pituitary gland or genetics. Nephrogenic DI (NDI) occurs when the kidneys do not respond properly to vasopressin. Dipsogenic DI is a result of excessive fluid intake due to damage to the hypothalamic thirst mechanism. It occurs more often in those with certain psychiatric disorders or on certain medications. Gestational DI occurs only during pregnancy. Diagnosis is often based on urine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatigue (medical)
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve after rest or sleep, or occurs independently of physical or mental exertion, it may be a symptom of a medical condition that may become severe or progressive. Fatigue can be a feature of a mental disorder such as depression; may be associated with conditions of chronic pain such as fibromyalgia; it may also feature in conditions of chronic low-level inflammation, and be a disease-related symptom in many other conditions. Fatigue often has no known cause, and is recognised as being very complex in nature. Fatigability describes a susceptibility to fatigue. Physical fatigue results from muscle fatigue brought about by intense physical activity. Mental fatigue results from prolonged periods of cognitive activity which impairs cognitive abil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
