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Numbness
Hypoesthesia or numbness is a common side effect of various medical conditions that manifests as a reduced sense of touch or sensation, or a partial loss of sensitivity to sensory stimuli. In everyday speech this is generally referred to as numbness. Hypoesthesia primarily results from damage to nerves, and from blockages in blood vessels, resulting in ischemic damage to tissues supplied by the blocked blood vessels. This damage is detectable through the use of various imaging studies. Damage in this way is caused by a variety of different illnesses and diseases. A few examples of the most common illnesses and diseases that can cause hypoesthesia as a side effect are as follows: * Decompression sickness * Trigeminal schwannoma * Rhombencephalitis * Intradural extramedullary tuberculoma of the spinal cord * Cutaneous sensory disorder * Beriberi Diseases Decompression sickness Decompression sickness occurs during rapid ascent, spanning 20 or more feet (typically from unde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompression Sickness
Decompression sickness (abbreviated DCS; also called divers' disease, the bends, aerobullosis, and caisson disease) is a medical condition caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompression. DCS most commonly occurs during or soon after a decompression ascent from underwater diving, but can also result from other causes of depressurisation, such as emerging from a caisson, decompression from saturation, flying in an unpressurised aircraft at high altitude, and extravehicular activity from spacecraft. DCS and arterial gas embolism are collectively referred to as decompression illness. Since bubbles can form in or migrate to any part of the body, DCS can produce many symptoms, and its effects may vary from joint pain and rashes to paralysis and death. DCS often causes air bubbles to settle in major joints like knees or elbows, causing individuals to bend over in excruciating pain, hence its common name, the bends. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paresthesia
Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias are usually painless and can occur anywhere on the body, but most commonly occur in the arms and legs. The most familiar kind of paresthesia is the sensation known as "pins and needles" after having a limb "fall asleep". A less well-known and uncommon paresthesia is formication, the sensation of insects crawling on the skin. Causes Transient Paresthesias of the hands, feet, legs, and arms are common transient symptoms. The briefest electric shock type of paresthesia can be caused by tweaking the ulnar nerve near the elbow; this phenomenon is colloquially known as bumping one's "funny bone". Similar brief shocks can be experienced when any other nerve is tweaked (e.g. a pinched neck nerve may cause a brief shock-like paresthesia toward t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beriberi
Thiamine deficiency is a medical condition of low levels of thiamine (Vitamin B1). A severe and chronic form is known as beriberi. The two main types in adults are wet beriberi and dry beriberi. Wet beriberi affects the cardiovascular system, resulting in a fast heart rate, shortness of breath, and leg swelling. Dry beriberi affects the nervous system, resulting in numbness of the hands and feet, confusion, trouble moving the legs, and pain. A form with loss of appetite and constipation may also occur. Another type, acute beriberi, found mostly in babies, presents with loss of appetite, vomiting, lactic acidosis, changes in heart rate, and enlargement of the heart. Risk factors include a diet of mostly white rice, alcoholism, dialysis, chronic diarrhea, and taking high doses of diuretics. In rare cases, it may be due to a genetic condition that results in difficulties absorbing thiamine found in food. Wernicke encephalopathy and Korsakoff syndrome are forms of dry beribe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raynaud Syndrome
Raynaud syndrome, also known as Raynaud's phenomenon, eponymously named after the physician Auguste Gabriel Maurice Raynaud, who first described it in his doctoral thesis in 1862, is a medical condition in which the spasm of small arteries causes episodes of reduced blood flow to end arterioles. Typically, the fingers, and less commonly, the toes, are involved. Rarely, the nose, ears, or lips are affected. The episodes classically result in the affected part turning white and then blue. Often, numbness or pain occurs. As blood flow returns, the area turns red and burns. The episodes typically last minutes but can last several hours. Episodes are typically triggered by cold or emotional stress. Primary Raynaud's, also known as idiopathic, means that it is spontaneous, of unknown cause, and unrelated to another disease. Secondary Raynaud's occurs as a result of another condition and has an older age at onset; episodes are intensely painful and can be asymmetric and associated wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysesthesia
Dysesthesia is an unpleasant, abnormal sense of touch. Its etymology comes from the Greek word "dys," meaning "bad," and "aesthesis," which means "sensation" (abnormal sensation). It often presents as pain Joseph J. Marbach, Joseph Marbach hypothesized that the symptoms were rooted in psychiatric disorders. Marbach suggested that occlusal dysesthesia would occur in patients with underlying psychological problems (such as schizophrenia) after having undergone dental treatment. More recently, two studies have found that occlusal dysesthesia is associated with somatoform disorders in which the patients obsess over the oral sensations. Similarly, Marbach later proposed that occlusal dysesthesia may be caused by the brain “talking to itself,” causing abnormal oral sensations in the absence of external stimuli. According to this model, the symptoms of dysesthesia are catalyzed by dental “amputation,” for example the extraction of a tooth, whereby the brain loses the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Touch
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 peripher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Root Schwannoma - Intermed Mag
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system. Each axon, within the nerve, is an extension of an individual neuron, along with other supportive cells such as some Schwann cells that coat the axons in myelin. Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium. The axons are bundled together into groups called fascicles, and each fascicle is wrapped in a layer of connective tissue called the perineurium. Finally, the entire nerve is wrapped in a layer of connective tissue called the epineurium. Nerve cells (often called neurons) are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain (precursor structures exist in onychophorans, gastropods and lancelets). The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal cord are both enclosed in the meninges. The meninges provide a barrier to chemicals d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperesthesia
Hyperesthesia is a condition that involves an abnormal increase in sensitivity to stimuli of the sense. Stimuli of the senses can include sound that one hears, foods that one tastes, textures that one feels, and so forth. Increased touch sensitivity is referred to as "tactile hyperesthesia", and increased sound sensitivity is called "auditory hyperesthesia". In the context of pain hyperaesthesia can refer to an increase in sensitivity where there is both allodynia and hyperalgesia. In psychology, Jeanne Siaud-Facchin uses the term by defining it as an "exacerbation des sens" that characterizes gifted individuals: for them, the sensory information reaches the brain much faster than the average, and the information is processed in a significantly shorter time. Other animals Feline hyperesthesia syndrome is an uncommon but recognized condition in cats, particularly Siamese, Burmese, Himalayan, and Abyssinian cats. It can affect cats of all ages, though it is most prevalent du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaphia
Anaphia, also known as tactile anesthesia, is a medical symptom in which there is a total or partial absence of the sense of touch. Anaphia is a common symptom of spinal cord injury and neuropathy. See also * Dysesthesia * Hyperesthesia * Hypoesthesia Hypoesthesia or numbness is a common side effect of various medical conditions that manifests as a reduced sense of touch or sensation, or a partial loss of sensitivity to Sensory receptor, sensory stimuli. In everyday speech this is generally r ... References Symptoms and signs of mental disorders Symptoms and signs: Nervous and musculoskeletal systems Neurological disorders Anesthesia {{symptom-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patellar Reflex
The patellar reflex, also called the knee reflex or knee-jerk, is a stretch reflex which tests the L2, L3, and L4 segments of the spinal cord. Mechanism Striking of the patellar tendon with a reflex hammer just below the patella stretches the muscle spindle in the quadriceps muscle. This produces a signal which travels back to the spinal cord and synapses (without interneurons) at the level of L3 or L4 in the spinal cord, completely independent of higher centres. From there, an alpha motor neuron conducts an efferent impulse back to the quadriceps femoris muscle, triggering contraction. This contraction, coordinated with the relaxation of the antagonistic flexor hamstring muscle causes the leg to kick. There is a latency of around 18 ms between stretch of the patellar tendon and the beginning of contraction of the quadriceps femoris muscle. This is a reflex of proprioception which helps maintain posture and balance, allowing to keep one's balance with little effort or conscio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans. MRI is a medical application of nuclear magnetic resonance (NMR) which can also be used for imaging in other NMR applications, such as NMR spectroscopy. MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of disease. Compared to CT, MRI provides better contrast in images of soft tissues, e.g. in the brain or abdomen. However, it may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, although "open ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
