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Myotonic Facies
Myotonia is a symptom of a small handful of certain neuromuscular disorders characterized by delayed relaxation (prolonged contraction) of the skeletal muscles after voluntary contraction or electrical stimulation. Myotonia is the defining symptom of many channelopathies such as myotonia congenita, paramyotonia congenita and myotonic dystrophy. Generally, repeated contraction of the muscle can alleviate the myotonia and relax the muscles thus improving the condition, however, this is not the case in paramyotonia congenita. This phenomenon is known as the "warm-up" reflex and is not to be confused with warming up before exercise, though they may appear similar. Individuals with the disorder may have trouble releasing their grip on objects or may have difficulty rising from a sitting position and a stiff, awkward gait. Myotonia can affect all muscle groups; however, the pattern of affected muscles can vary depending on the specific disorder involved. People with disorders involvi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromuscular
A neuromuscular junction (or myoneural junction) is a chemical synapse between a motor neuron and a muscle fiber. It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction. Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy. In the neuromuscular system nerves from the central nervous system and the peripheral nervous system are linked and work together with muscles. Synaptic transmission at the neuromuscular junction begins when an action potential reaches the presynaptic terminal of a motor neuron, which activates voltage-gated calcium channels to allow calcium ions to enter the neuron. Calcium ions bind to sensor proteins (synaptotagmins) on synaptic vesicles, triggering vesicle fusion with the cell membrane and subsequent neurotransmitter release from the motor neuron into the synaptic cleft. In vertebrates, motor neurons release acetylcholine (ACh), a small molecule neurotransmitter, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium-aggravated Myotonia
Potassium-aggravated myotonia is a rare genetic disorder that affects skeletal muscle. Beginning in childhood or adolescence, people with this condition experience bouts of sustained muscle tensing (myotonia) that prevent muscles from relaxing normally. Myotonia causes muscle stiffness, often painful, that worsens after exercise and may be aggravated by eating potassium-rich foods such as bananas and potatoes. Stiffness occurs in skeletal muscles throughout the body. Potassium-aggravated myotonia ranges in severity from mild episodes of muscle stiffness to severe, disabling disease with frequent attacks. Potassium-aggravated myotonia may, in some cases, also cause paradoxical myotonia, in which myotonia becomes more severe at the time of movement instead of after movement has ceased. Unlike some other forms of myotonia, potassium-aggravated myotonia is not associated with episodes of muscle weakness. Mutations in the ''SCN4A'' gene cause potassium-aggravated myotonia. The ''SCN4A'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symptoms And Signs: Nervous System
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showing on a medical scan. A symptom is something out of the ordinary that is experienced by an individual such as feeling feverish, a headache or other pain or pains in the body. Signs and symptoms Signs A medical sign is an objective observable indication of a disease, injury, or abnormal physiological state that may be detected during a physical examination, examining the patient history, or diagnostic procedure. These signs are visible or otherwise detectable such as a rash or bruise. Medical signs, along with symptoms, assist in formulating diagnostic hypothesis. Examples of signs include elevated blood pressure, nail clubbing of the fingernails or toenails, staggering gait, and arcus senilis and arcus juvenilis of the eyes. Indicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malignant Hyperthermia
Malignant hyperthermia (MH) is a type of severe reaction that occurs in response to particular medications used during General anaesthesia, general anesthesia, among those who are susceptible. Symptoms include tetany, muscle rigidity, hyperthermia, fever, and a tachycardia, fast heart rate. Complications can include rhabdomyolysis, muscle breakdown and hyperkalemia, high blood potassium. Most people who are susceptible to MH are generally unaffected when not exposed to triggering agents. Exposure to triggering agents (certain inhalational anaesthetic, volatile anesthetic agents or Suxamethonium chloride, succinylcholine) can lead to the development of MH in those who are susceptible. Susceptibility can occur due to at least six genetic mutations, with the most common one being of the RYR1 gene. These genetic variations are often inherited from a person's parents in an Dominance (genetics), autosomal dominant manner. The condition may also occur as a new mutation or be associated w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromuscular Medicine
Neuromuscular medicine is a subspecialty of neurology and physiatry that focuses the diagnosis and management of neuromuscular diseases. The field encompasses issues related to both diagnosis and management of these conditions, including rehabilitation interventions to optimize the quality of life of individuals with these conditions. This field encompasses disorders that impact both adults and children. Neuromuscular disease can be caused by autoimmune disorders, genetic or hereditary disorders such as channelopathies, or neurodegenerative diseases. Because they frequently have no cure, the focus is managing the condition to provide improvements in the patients quality. Rehabilitation robotics is a new frontier for neurological rehabilitation treatments. Diagnostic tools The tools used to diagnose neuromuscular disorders include nerve and muscle biopsies, electromyography, nerve conduction studies, and molecular and genetic tests. See also * List of neuromuscular disorders * M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperekplexia
Hyperekplexia (; "exaggerated surprise") is a very rare neurologic disorder classically characterised by pronounced startle responses to tactile or acoustic stimuli and hypertonia. The hypertonia may be predominantly truncal, attenuated during sleep and less prominent after a year of age. Classic hyperekplexia is caused by genetic mutations in a number of different genes, all of which play an important role in glycine neurotransmission. Glycine is used by the central nervous system as an inhibitory neurotransmitter. Hyperekplexia is generally classified as a genetic disease, but some disorders can mimic the exaggerated startle of hyperekplexia. Signs and symptoms The three main signs of hyperekplexia are generalized stiffness, excessive startle beginning at birth and nocturnal myoclonus. Affected individuals are fully conscious during episodes of stiffness, which consist of forced closure of the eyes and an extension of the extremities followed by a period of generalised stiffn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schwartz–Jampel Syndrome
Schwartz–Jampel syndrome (SJS) is a rare genetic disease caused by a mutation in the perlecan gene (''HSPG2'') which causes osteochondrodysplasia associated with myotonia. Most people with Schwartz–Jampel syndrome have a nearly normal life expectancy. Cause Schwartz–Jampel syndrome is caused by mutations in the ''HSPG2'' gene, which makes the protein perlecan, which is found in muscle and cartilage. Relationships between the disease and perlecan deficiency have been studied. In Schwartz–Jampel syndrome, it is suspected that abnormal perlecan function leads to a deficiency in acetylcholinesterase, an enzyme involved in breaking down the neurotransmitter acetylcholine, which incites muscle contraction. If acetylcholine is not broken down, it can lead to prolonged muscle contraction/stiffening of the muscles (myotonia). Diagnosis Schwartz–Jampel syndrome is diagnosed on the basis of characteristic facial features, skeletal features and myotonia. Blood tests may show elevat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle tissue, and are often known as muscle fibers. The muscle tissue of a skeletal muscle is striated – having a striped appearance due to the arrangement of the sarcomeres. Skeletal muscles are voluntary muscles under the control of the somatic nervous system. The other types of muscle are cardiac muscle which is also striated and smooth muscle which is non-striated; both of these types of muscle tissue are classified as involuntary, or, under the control of the autonomic nervous system. A skeletal muscle contains multiple fascicles – bundles of muscle fibers. Each individual fiber, and each muscle is surrounded by a type of connective tissue layer of fascia. Muscle fibers are formed from the fusion of developmental myoblasts in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromyotonia
Neuromyotonia (NMT) is a form of peripheral nerve hyperexcitability that causes spontaneous muscular activity resulting from repetitive motor unit action potentials of peripheral origin. NMT along with Morvan's syndrome are the most severe types in the Peripheral Nerve Hyperexciteability spectrum. Example of two more common and less severe syndromes in the spectrum are Cramp Fasciculation Syndrome and Benign Fasciculation Syndrome. NMT can have both hereditary and acquired (non- inherited) forms. The prevalence of NMT is unknown. Signs and symptoms NMT is a diverse disorder. As a result of muscular hyperactivity, patients may present with muscle cramps, stiffness, myotonia-like symptoms (slow relaxation), associated walking difficulties, hyperhidrosis (excessive sweating), myokymia (quivering of a muscle), fasciculations (muscle twitching), fatigue, exercise intolerance, myoclonic jerks and other related symptoms. The symptoms (especially the stiffness and fasciculations) are mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypokalemia
Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an abnormal heart rhythm, which is often too slow and can cause cardiac arrest. Causes of hypokalemia include vomiting, diarrhea, medications like furosemide and steroids, dialysis, diabetes insipidus, hyperaldosteronism, hypomagnesemia, and not enough intake in the diet. Normal potassium levels are between 3.5 and 5.0 mmol/L (3.5 and 5.0 mEq/L) with levels below 3.5 mmol/L defined as hypokalemia. It is classified as severe when levels are less than 2.5 mmol/L. Low levels may also be suspected based on an electrocardiogram (ECG). Hyperkalemia is a high level of potassium in the blood serum. The speed at which potassium should be replaced depends on whether or not there are symptoms or abnormalities on an electrocardiogram. Potas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypokalemic Periodic Paralysis
Hypokalemic periodic paralysis (hypoKPP), also known as familial hypokalemic periodic paralysis (FHPP), is a rare, autosomal dominant channelopathy characterized by muscle weakness or paralysis when there is a fall in potassium levels in the blood. In individuals with this mutation, attacks sometimes begin in adolescence and most commonly occur with individual triggers such as rest after strenuous exercise (attacks during exercise are rare), high carbohydrate meals, meals with high sodium content, sudden changes in temperature, and even excitement, noise, flashing lights, cold temperatures and stress. Weakness may be mild and limited to certain muscle groups, or more severe full-body paralysis. During an attack, reflexes may be decreased or absent. Attacks may last for a few hours or persist for several days. Recovery is usually sudden when it occurs, due to release of potassium from swollen muscles as they recover. Some patients may fall into an abortive attack or develop chronic m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperkalemia
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasionally when severe it can cause palpitations, muscle pain, muscle weakness, or numbness. Hyperkalemia can cause an abnormal heart rhythm which can result in cardiac arrest and death. Common causes of hyperkalemia include kidney failure, hypoaldosteronism, and rhabdomyolysis. A number of medications can also cause high blood potassium including spironolactone, NSAIDs, and angiotensin converting enzyme inhibitors. The severity is divided into mild (5.5–5.9mmol/L), moderate (6.0–6.4mmol/L), and severe (>6.5mmol/L). High levels can be detected on an electrocardiogram (ECG). Pseudohyperkalemia, due to breakdown of cells during or after taking the blood sample, should be ruled out. Initial treatment in those with ECG changes is salts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
