Carotid Body Tumor
Carotid Body
Vagus Nerve Injuries
Horner Syndrome
Aortic Bodies
Paraganglioma
Paraganglioma, Extra-Adrenal
Succinate Dehydrogenase
Carotid Arteries
Chemoreceptor Cells
Carotid Stenosis
Head and Neck Neoplasms
Familial carotid body tumors: a closer look. (1/77)
PURPOSE: A family spanning three generations with a history of familial carotid body tumors (CBTs) was studied, and previously proposed hypotheses of tumor characteristics and genetic mode of transmission were addressed. METHODS: Clinically occult lesions in adult subjects were detected by means of high-resolution computed tomography. RESULTS: A 60% incidence of bilaterality of CBTs associated with multiple paragangliomas was noted in the family studied. The genetic mode for CBTs in this family was not simple autosomal dominant transmission and appeared to be paternally directed with complete penetrance. CONCLUSION: In patients with familial CBTs, high-resolution computed tomography is recommended for early screening as a means of prompting diagnosis and definitive treatment, an approach that minimizes morbidity and facilitates surgical excision. (+info)Mutations in SDHD, a mitochondrial complex II gene, in hereditary paraganglioma. (2/77)
Hereditary paraganglioma (PGL) is characterized by the development of benign, vascularized tumors in the head and neck. The most common tumor site is the carotid body (CB), a chemoreceptive organ that senses oxygen levels in the blood. Analysis of families carrying the PGL1 gene, described here, revealed germ line mutations in the SDHD gene on chromosome 11q23. SDHD encodes a mitochondrial respiratory chain protein-the small subunit of cytochrome b in succinate-ubiquinone oxidoreductase (cybS). In contrast to expectations based on the inheritance pattern of PGL, the SDHD gene showed no evidence of imprinting. These findings indicate that mitochondria play an important role in the pathogenesis of certain tumors and that cybS plays a role in normal CB physiology. (+info)Bilateral carotid body paraganglioma: case report. (3/77)
CONTEXT: Surgical treatment of carotid body paragangliomas is a challenge to the surgeon because of the large vascularization of the tumor, involvement of the carotid vessels and the close anatomical relationship with the cranial nerves. CASE REPORT: A 63-year-old patient was submitted to resection of two carotid body paraganglioma tumors found in the right-side and left-side carotid bodies at the bifurcation of the common carotid arteries. Two surgeries were performed at different times and neither of them presented any morbidity. Arteriography was fundamental for diagnosis of the small, asymptomatic tumor on the right side. DESIGN: Case Report (+info)Baroreflex failure syndrome after bilateral excision of carotid body tumors: an underestimated problem. (4/77)
Carotid body tumors (CBTs) are relatively rare paragangliomas that develop from neural crest cells at the bifurcation of the common carotid artery. They are generally slow growing and benign. Excision is currently considered the treatment of choice, although vascular and especially neural injuries are still relatively frequent in patients with large or bilaterally resected tumors. The baroreflex failure syndrome (BFS) has recently been identified as a severe, rarely recognized, and certainly underestimated complication after the bilateral excision of CBTs. The present report describes a case of a bilateral CBT followed by BFS and reviews the experiences reported in the literature. In light of the low incidence of malignancy of these tumors, their biologic behavior, their very high rate of cranial nerve palsy, and the occurrence of BFS in bilaterally resected paragangliomas, the current practice of bilaterally removing these tumors is questioned. (+info)Power Doppler scanning in the diagnosis of carotid body tumors. (5/77)
The aim of this work was to show contribution of power Doppler imaging in the diagnosis of the carotid body tumors. Six patients with a nontender mass beneath the mandibular angle were evaluated with gray scale and power Doppler sonography. Well-defined, solid, weakly hyperechoic masses were noted on gray scale sonography in the carotid bifurcation. Power Doppler sonography showed abundant flow, characterized as an intense blush, throughout the entire tumor in all patients. We believe that invasive and expensive diagnostic modalities are not necessary to evaluate carotid body tumors. Gray scale sonography and power Doppler imaging are sufficient for primary diagnosis of carotid body tumors. (+info)Malignant carotid body tumor: a case report. (6/77)
Carotid body tumors (CBTs) have an unpredictable history with no correlation between histology and clinical behavior. Of reported cases since 1891, local and distant metastases appear in approximately 10% of cases and remain the hallmark of malignancy. Currently, there are not enough data to support a single treatment regimen for malignant CBTs. The reported case demonstrates some unanswered issues with regard to malignant CBTs to include lymph node dissection, the need for carotid resection, and the role of radiation therapy. A 46-year-old pathologist underwent a resection of a Shamblin I CBT, to include jugular lymph node sampling, without complication. There was lymph node involvement, and tumor cells were found on the margins of the pathologic specimen. Subsequent carotid resection with reversed interposition saphenous vein graft and modified neck dissection were performed again without complication. Follow-up at 4 years has been uneventful. Diagnosis of CBTs with the use of magnetic resonance angiography, magnetic resonance imaging, color flow duplex scanning, and the role of arteriography are reviewed. The current treatment options are discussed with reference to primary lymph node sampling, carotid resection, and neck dissection in malignant cases. This case demonstrates that the unpredictable nature of CBTs and their malignant potential warrant aggressive initial local treatment to include jugular lymph node sampling and complete tumor resection. (+info)Long-term effects of carotid sinus denervation on arterial blood pressure in humans. (7/77)
BACKGROUND: After experimental carotid sinus denervation in animals, blood pressure (BP) level and variability increase markedly but normalize to preoperative levels within 10 to 14 days. We investigated the course of arterial BP level and variability after bilateral denervation of the carotid sinus baroreceptors in humans. METHODS AND RESULTS: We studied 4 women (age 41 to 63 years) who were referred for evaluation of arterial baroreflex function because of clinical suspicion of carotid sinus denervation attributable to bilateral carotid body tumor resection. The course of BP level and variability was assessed from repeated office and 24-hour ambulatory measurements (Spacelabs/Portapres) during 1 to 10 years of (retrospective) follow-up. Rapid cardiovascular reflex adjustments to active standing and Valsalva's maneuver were assessed. Office BP level increased from 132/86 mm Hg (range, 118 to 148/80 to 92 mm Hg) before bilateral surgery to 160/105 mm Hg (range, 143 to 194/90 to 116 mm Hg) 1 to 10 years after surgery. During continuous 24-hour noninvasive BP recording (Portapres), a marked BP variability was apparent in all 4 patients. Initial symptomatic hypotension on change to the upright posture and abnormal responses to Valsalva's maneuver were observed. CONCLUSIONS: Acute carotid sinus denervation, as a result of bilateral carotid body tumor resection, has a long-term effect on the level, variability, and rapid reflex control of arterial BP. Therefore, in contrast to earlier experimental observations, the compensatory ability of the baroreceptor areas outside the carotid sinus seems to be of limited importance in the regulation of BP in humans. (+info)Baroreflex control of muscle sympathetic nerve activity after carotid body tumor resection. (8/77)
Bilateral carotid body tumor resection causes a permanent attenuation of vagal baroreflex sensitivity. We retrospectively examined the effects of bilateral carotid body tumor resection on the baroreflex control of sympathetic nerve traffic. Muscle sympathetic nerve activity was recorded in 5 patients after bilateral carotid body tumor resection (1 man and 4 women, 51+/-11 years) and 6 healthy control subjects (2 men and 4 women, 50+/-7 years). Baroreflex sensitivity was calculated from changes in R-R interval and muscle sympathetic nerve activity in response to bolus injections of phenylephrine and nitroprusside. In addition, sympathetic responses to the Valsalva maneuver and cold pressor test were measured. The integrated neurogram of patients and control subjects contained a similar pattern of pulse synchronous burst of nerve activity. Baroreflex control of both heart rate and sympathetic nerve activity were attenuated in patients as compared with control subjects [heart rate baroreflex sensitivity: 3.68+/-0.93 versus 11.61+/-4.72 ms/mm Hg (phenylephrine, P=0.011) and 2.53+/-1.36 versus 5.82+/-1.94 ms/mm Hg (nitroprusside, P=0.05); sympathetic baroreflex sensitivity: 3.70+/-2.90 versus 7.53+/-4.12 activity/100 beats/mm Hg (phenylephrine, P=0.10) and 3.93+/-4.43 versus 15.27+/-10.03 activity/100 beats/mm Hg (nitroprusside, P=0.028)]. The Valsalva maneuver elicited normal reflex changes in muscle sympathetic nerve activity, whereas heart rate responses were blunted in the patients with bilateral carotid body tumor resection. Maximal sympathetic responses to the cold pressor test did not differ between the two groups. Denervation of carotid sinus baroreceptors as the result of bilateral carotid body tumor resection produces chronic impairment of baroreflex control of both heart rate and sympathetic nerve activity. During the Valsalva maneuver, loss of carotid baroreflex control of heart rate is less well compensated for by the extra carotid baroreceptors than the control of muscle sympathetic nerve activity. (+info)A carotid body tumor is a rare, usually noncancerous (benign) growth that develops in the carotid body, a small structure located near the bifurcation (fork) of the common carotid artery in the neck. The carotid body is part of the chemoreceptor system that helps regulate breathing and blood pressure by responding to changes in oxygen, carbon dioxide, and pH levels in the blood.
Carotid body tumors are also known as carotid body paragangliomas or chemodectomas. They typically grow slowly and may not cause any symptoms for many years. However, as they enlarge, they can cause a visible or palpable mass in the neck, along with symptoms such as difficulty swallowing, hoarseness, or voice changes. In some cases, carotid body tumors can compress nearby nerves or blood vessels, leading to more serious complications like stroke or nerve damage.
Treatment for carotid body tumors typically involves surgical removal of the growth, which may be performed using traditional open surgery or minimally invasive techniques such as endovascular surgery or robotic-assisted surgery. Radiation therapy and chemotherapy are generally not effective in treating these tumors. Regular follow-up care is important to monitor for recurrence or development of new tumors.
The carotid body is a small chemoreceptor organ located near the bifurcation of the common carotid artery into the internal and external carotid arteries. It plays a crucial role in the regulation of respiration, blood pressure, and pH balance by detecting changes in the chemical composition of the blood, particularly oxygen levels, carbon dioxide levels, and hydrogen ion concentration (pH).
The carotid body contains specialized nerve endings called glomus cells that are sensitive to changes in these chemical parameters. When there is a decrease in oxygen or an increase in carbon dioxide or hydrogen ions, the glomus cells release neurotransmitters such as acetylcholine and dopamine, which activate afferent nerve fibers leading to the brainstem's nucleus tractus solitarius. This information is then integrated with other physiological signals in the brainstem, resulting in appropriate adjustments in breathing rate, depth, and pattern, as well as changes in heart rate and blood vessel diameter to maintain homeostasis.
Dysfunction of the carotid body can lead to various disorders, such as hypertension, sleep apnea, and chronic lung disease. In some cases, overactivity of the carotid body may result in conditions like primary breathing pattern disorders or pseudohypoxia, where the body responds as if it is experiencing hypoxia despite normal oxygen levels.
Vagus nerve injuries refer to damages or traumas affecting the vagus nerve, which is the tenth cranial nerve (CN X) in the human body. This nerve plays a crucial role in the autonomic nervous system, regulating essential functions such as heart rate, respiratory rate, and digestion.
Vagus nerve injuries can occur due to various reasons, including trauma during surgical procedures, neck or head injuries, inflammation, compression, or tumors affecting the nerve. Symptoms of vagus nerve injuries may include:
1. Hoarseness or voice changes
2. Difficulty swallowing (dysphagia)
3. Pain in the throat or ear
4. Changes in heart rate and blood pressure
5. Nausea, vomiting, or abdominal pain
6. Shortness of breath or difficulty breathing
The severity and nature of symptoms can vary depending on the location and extent of the injury to the vagus nerve. Treatment for vagus nerve injuries typically involves addressing the underlying cause, such as surgical intervention, physical therapy, or medication to manage pain and inflammation. In some cases, recovery may be incomplete, leading to long-term complications or disabilities.
Hypoglossal nerve injuries refer to damages or impairments to the twelfth cranial nerve, also known as the hypoglossal nerve. This nerve is primarily responsible for controlling the movements of the tongue.
An injury to this nerve can result in various symptoms, depending on the severity and location of the damage. These may include:
1. Deviation of the tongue to one side when protruded (usually away from the side of the lesion)
2. Weakness or paralysis of the tongue muscles
3. Difficulty with speaking, swallowing, and articulation
4. Changes in taste and sensation on the back of the tongue (in some cases)
Hypoglossal nerve injuries can occur due to various reasons, such as trauma, surgical complications, tumors, or neurological disorders like stroke or multiple sclerosis. Treatment for hypoglossal nerve injuries typically focuses on managing symptoms and may involve speech and language therapy, exercises to strengthen the tongue muscles, and, in some cases, surgical intervention.
Horner syndrome, also known as Horner's syndrome or oculosympathetic palsy, is a neurological disorder characterized by the interruption of sympathetic nerve pathways that innervate the head and neck, leading to a constellation of signs affecting the eye and face on one side of the body.
The classic triad of symptoms includes:
1. Ptosis (drooping) of the upper eyelid: This is due to the weakness or paralysis of the levator palpebrae superioris muscle, which is responsible for elevating the eyelid.
2. Miosis (pupillary constriction): The affected pupil becomes smaller in size compared to the other side, and it may not react as robustly to light.
3. Anhydrosis (decreased sweating): There is reduced or absent sweating on the ipsilateral (same side) of the face, particularly around the forehead and upper eyelid.
Horner syndrome can be caused by various underlying conditions, such as brainstem stroke, tumors, trauma, or certain medical disorders affecting the sympathetic nervous system. The diagnosis typically involves a thorough clinical examination, pharmacological testing, and sometimes imaging studies to identify the underlying cause. Treatment is directed towards managing the underlying condition responsible for Horner syndrome.
Aortic bodies, also known as aortic arch chemoreceptors or simply as carotid and aortic bodies, are small clusters of nerve cells located near the bifurcation of the common carotid artery (carotid body) and in the wall of the aortic arch (aortic body). They are part of the peripheral chemoreceptor system that responds to changes in chemical composition of the blood, particularly to decreases in oxygen levels, increases in carbon dioxide levels, and changes in pH. These receptors send signals to the brainstem, which in turn regulates breathing rate and depth to maintain adequate gas exchange and acid-base balance in the body.
Paraganglioma is a rare type of tumor that develops in the nervous system, specifically in the paraganglia. Paraganglia are clusters of specialized nerve cells throughout the body that release hormones in response to stress or physical activity. Most paragangliomas are benign (noncancerous), but some can be malignant (cancerous) and may spread to other parts of the body.
Paragangliomas can occur in various locations, including the head and neck region (called "head and neck paragangliomas") or near the spine, abdomen, or chest (called "extra-adrenal paragangliomas"). When they develop in the adrenal glands, which are located on top of each kidney, they are called pheochromocytomas.
Paragangliomas can produce and release hormones such as epinephrine (adrenaline) and norepinephrine, leading to symptoms like high blood pressure, rapid heart rate, sweating, anxiety, and headaches. Treatment typically involves surgical removal of the tumor, along with medications to manage symptoms and control hormone levels before and after surgery.
Paraganglioma, extra-adrenal, is a type of rare tumor that develops in the nervous system's paraganglia, which are groups of specialized cells that are responsible for regulating blood pressure and other bodily functions. Unlike adrenal paragangliomas, which form in the adrenal glands located on top of the kidneys, extra-adrenal paragangliomas develop outside of the adrenal glands, in various locations along the sympathetic and parasympathetic nervous systems. These tumors can be functional or nonfunctional, meaning they may or may not produce hormones such as catecholamines (epinephrine, norepinephrine, and dopamine). Functional extra-adrenal paragangliomas can cause symptoms related to excessive hormone production, including hypertension, sweating, headaches, and rapid heartbeat. Treatment typically involves surgical removal of the tumor, along with preoperative preparation to manage potential hormonal imbalances.
Succinate dehydrogenase (SDH) is an enzyme complex that plays a crucial role in the process of cellular respiration, specifically in the citric acid cycle (also known as the Krebs cycle) and the electron transport chain. It is located in the inner mitochondrial membrane of eukaryotic cells.
SDH catalyzes the oxidation of succinate to fumarate, converting it into a molecule of fadaquate in the process. During this reaction, two electrons are transferred from succinate to the FAD cofactor within the SDH enzyme complex, reducing it to FADH2. These electrons are then passed on to ubiquinone (CoQ), which is a mobile electron carrier in the electron transport chain, leading to the generation of ATP, the main energy currency of the cell.
SDH is also known as mitochondrial complex II because it is the second complex in the electron transport chain. Mutations in the genes encoding SDH subunits or associated proteins have been linked to various human diseases, including hereditary paragangliomas, pheochromocytomas, gastrointestinal stromal tumors (GISTs), and some forms of neurodegenerative disorders.
The carotid arteries are a pair of vital blood vessels in the human body that supply oxygenated blood to the head and neck. Each person has two common carotid arteries, one on each side of the neck, which branch off from the aorta, the largest artery in the body.
The right common carotid artery originates from the brachiocephalic trunk, while the left common carotid artery arises directly from the aortic arch. As they ascend through the neck, they split into two main branches: the internal and external carotid arteries.
The internal carotid artery supplies oxygenated blood to the brain, eyes, and other structures within the skull, while the external carotid artery provides blood to the face, scalp, and various regions of the neck.
Maintaining healthy carotid arteries is crucial for overall cardiovascular health and preventing serious conditions like stroke, which can occur when the arteries become narrowed or blocked due to the buildup of plaque or fatty deposits (atherosclerosis). Regular check-ups with healthcare professionals may include monitoring carotid artery health through ultrasound or other imaging techniques.
Chemoreceptor cells are specialized sensory neurons that detect and respond to chemical changes in the internal or external environment. They play a crucial role in maintaining homeostasis within the body by converting chemical signals into electrical impulses, which are then transmitted to the central nervous system for further processing and response.
There are two main types of chemoreceptor cells:
1. Oxygen Chemoreceptors: These cells are located in the carotid bodies near the bifurcation of the common carotid artery and in the aortic bodies close to the aortic arch. They monitor the levels of oxygen, carbon dioxide, and pH in the blood and respond to decreases in oxygen concentration or increases in carbon dioxide and hydrogen ions (indicating acidity) by increasing their firing rate. This signals the brain to increase respiratory rate and depth, thereby restoring normal oxygen levels.
2. Taste Cells: These chemoreceptor cells are found within the taste buds of the tongue and other areas of the oral cavity. They detect specific tastes (salty, sour, sweet, bitter, and umami) by interacting with molecules from food. When a tastant binds to receptors on the surface of a taste cell, it triggers a series of intracellular signaling events that ultimately lead to the generation of an action potential. This information is then relayed to the brain, where it is interpreted as taste sensation.
In summary, chemoreceptor cells are essential for maintaining physiological balance by detecting and responding to chemical stimuli in the body. They play a critical role in regulating vital functions such as respiration and digestion.
Carotid stenosis is a medical condition that refers to the narrowing or constriction of the lumen (inner space) of the carotid artery. The carotid arteries are major blood vessels that supply oxygenated blood to the head and neck. Carotid stenosis usually results from the buildup of plaque, made up of fat, cholesterol, calcium, and other substances, on the inner walls of the artery. This process is called atherosclerosis.
As the plaque accumulates, it causes the artery to narrow, reducing blood flow to the brain. Severe carotid stenosis can increase the risk of stroke, as a clot or debris from the plaque can break off and travel to the brain, blocking a smaller blood vessel and causing tissue damage or death.
Carotid stenosis is typically diagnosed through imaging tests such as ultrasound, CT angiography, or MRI angiography. Treatment options may include lifestyle modifications (such as quitting smoking, controlling blood pressure, and managing cholesterol levels), medications to reduce the risk of clots, or surgical procedures like endarterectomy or stenting to remove or bypass the blockage.
Head and neck neoplasms refer to abnormal growths or tumors in the head and neck region, which can be benign (non-cancerous) or malignant (cancerous). These tumors can develop in various sites, including the oral cavity, nasopharynx, oropharynx, larynx, hypopharynx, paranasal sinuses, salivary glands, and thyroid gland.
Benign neoplasms are slow-growing and generally do not spread to other parts of the body. However, they can still cause problems if they grow large enough to press on surrounding tissues or structures. Malignant neoplasms, on the other hand, can invade nearby tissues and organs and may also metastasize (spread) to other parts of the body.
Head and neck neoplasms can have various symptoms depending on their location and size. Common symptoms include difficulty swallowing, speaking, or breathing; pain in the mouth, throat, or ears; persistent coughing or hoarseness; and swelling or lumps in the neck or face. Early detection and treatment of head and neck neoplasms are crucial for improving outcomes and reducing the risk of complications.