bowang0911/MedQuAD huggingface dataset:
Canavan disease is a gene-linked neurological disorder in which the brain degenerates into spongy tissue riddled with microscopic fluid-filled spaces. Canavan disease has been classified as one of a group of genetic disorders known as the leukodystrophies. Recent research has indicated that the cells in the brain responsible for making myelin sheaths, known as oligodendrocytes, cannot properly complete this critical developmental task. Myelin sheaths are the fatty covering that act as insulators around nerve fibers in the brain, as well as providing nutritional support for nerve cells. In Canavan disease, many oligodendrocytes do not mature and instead die, leaving nerve cell projections known as axons vulnerable and unable to properly function. Canavan disease is caused by mutation in the gene for an enzyme called aspartoacylase, which acts to break down the concentrated brain chemical known as N-acetyl-aspartate.
                
Symptoms of Canavan disease usually appear in the first 3 to 6 months of life and progress rapidly. Symptoms include lack of motor development, feeding difficulties, abnormal muscle tone (weakness or stiffness), and an abnormally large, poorly controlled head. Paralysis, blindness, or hearing loss may also occur. Children are characteristically quiet and apathetic. Although Canavan disease may occur in any ethnic group, it is more frequent among Ashkenazi Jews from eastern Poland, Lithuania, and western Russia, and among Saudi Arabians. Canavan disease can be identified by a simple prenatal blood test that screens for the missing enzyme or for mutations in the gene that controls aspartoacylase. Both parents must be carriers of the defective gene in order to have an affected child. When both parents are found to carry the Canavan gene mutation, there is a one in four (25 percent) chance with each pregnancy that the child will be affected with Canavan disease.
The gene for Canavan disease has been located. Many laboratories offer prenatal screening for this disorder to populations at risk. Scientists have developed animal models for this disease and are using the models to test potential therapeutic strategies. Three strategies are currently under investigation: gene transfer to the brain in order to replace the mutated gene for the enzyme; metabolic therapy to provide a crucial missing metabolite (acetate); and enzyme therapy where the enzyme aspartoacylase is engineered to be able to enter the brain and is injected in the the blood stream. Encouraging results have been obtained using these strategies.
Alexander disease is one of a group of neurological conditions known as the leukodystrophies, disorders that are the result of abnormalities in myelin, the white matter that protects nerve fibers in the brain. Alexander disease is a progressive and often fatal disease. The destruction of white matter is accompanied by the formation of Rosenthal fibers, which are abnormal clumps of protein that accumulate in non-neuronal cells of the brain called astrocytes. Rosenthal fibers are sometimes found in other disorders, but not in the same amount or area of the brain that are featured in Alexander disease. The infantile form is the most common type of Alexander disease. It has an onset during the first two years of life. Usually there are both mental and physical developmental delays, followed by the loss of developmental milestones, an abnormal increase in head size, and seizures. The juvenile form of Alexander disease is less common and has an onset between the ages of two and thirteen. These children may have excessive vomiting, difficulty swallowing and speaking, poor coordination, and loss of motor control. Adult-onset forms of Alexander disease are less common. The symptoms sometimes mimic those of Parkinsons disease or multiple sclerosis, or may present primarily as a psychiatric disorder. The disease occurs in both males and females, and there are no ethnic, racial, geographic, or cultural/economic differences in its distribution.
Recent discoveries show that most individuals (approximately 90 percent) with Alexander disease have a mutation in the gene that makes glial fibrillary acidic protein (GFAP). GFAP is a normal component of the brain, but it is unclear how the mutations in this genecauses the disease. In most cases mutations occur spontaneously are not inherited from parents.A small number of people thought to have Alexander disease do not have identifiable mutations in GFAP, which leads researchers to believe that there may be other genetic or perhaps even non-genetic causes of Alexander disease. Current research is aimed at understanding the mechanisms by which the mutations cause disease, developing better animal models for the disorder, and exploring potential strategies for treatment. At present, there is no exact animal model for the disease; however, mice have been engineered to produce the same mutant forms of GFAP found in individuals with Alexander disease. These mice form Rosenthal fibers and have a predisposition for seizures, but do not yet mimic all features of human disease (such as the leukodystrophies). One clinical study is underway to identify biomarkers of disease severity or progression in samples of blood or cerebrospinal fluid. Such biomarkers, if found, would be a major advantage for evaluating the response to any treatments that are developed in the future.
Narcolepsy is a chronic neurological disorder caused by the brain's inability to regulate sleep-wake cycles normally. At various times throughout the day, people with narcolepsy experience irresistable bouts ofsleep. If the urge becomes overwhelming, individuals will fall asleep for periods lasting from a few seconds to several minutes. In rare cases, some people may remain asleep for an hour or longer. In addition to excessive daytime sleepiness (EDS), three other major symptoms frequently characterize narcolepsy: cataplexy, or the sudden loss of voluntary muscle tone; vivid hallucinations during sleep onset or upon awakening; and brief episodes of total paralysis at the beginning or end of sleep. Narcolepsy is not definitively diagnosed in most patients until 10 to 15 years after the first symptoms appear. The cause of narcolepsy remains unknown. It is likely that narcolepsy involves multiple factors interacting to cause neurological dysfunction and sleep disturbances.
There is no cure for narcolepsy. In 1999, after successful clinical trial results, the U.S. Food and Drug Administration (FDA) approved a drug called modafinil for the treatment of EDS. Two classes of antidepressant drugs have proved effective in controlling cataplexy in many patients: tricyclics (including imipramine, desipramine, clomipramine, and protriptyline) and selective serotonin reuptake inhibitors (including fluoxetine and sertraline). Drug therapy should be supplemented by behavioral strategies. For example, many people with narcolepsy take short, regularly scheduled naps at times when they tend to feel sleepiest. Improving the quality of nighttime sleep can combat EDS and help relieve persistent feelings of fatigue. Among the most important common-sense measures people with narcolepsy can take to enhance sleep quality are actions such as maintaining a regular sleep schedule, and avoiding alcohol and caffeine-containing beverages before bedtime. The drug Xyrem (sodium oxybate or gamma hydroxybutyrate, also known as GHB) was approved in July 2002 for treating cataplexy and in November 2005 for EDS in people who have narcolepsy. Due to safety concerns associated with the use of this drug, the distribution of Xyrem is tightly restricted.
None of the currently available medications enables people with narcolepsy to consistently maintain a fully normal state of alertness. But EDS and cataplexy, the most disabling symptoms of the disorder, can be controlled in most patients with drug treatment. Often the treatment regimen is modified as symptoms change. Whatever the age of onset, patients find that the symptoms tend to get worse over the two to three decades after the first symptoms appear. Many older patients find that some daytime symptoms decrease in severity after age 60.
The National Institute of Neurological Disorders and Stroke (NINDS) and other institutes of the National Institutes of Health (NIH) conduct research into narcolepsy and other sleep disorders in laboratories at the NIH and also support additional research through grants to major medical institutions across the country. The NINDS continues to support investigations into the basic biology of sleep, including the brain mechanisms involved in generating and regulating sleep. Within the National Heart, Lung, and Blood Institute, also a component of the NIH, the       National        Center   on Sleep Disorders Research (NCSDR) coordinates Federal government sleep research activities and shares information with private and nonprofit groups.
AIDS is primarily an immune system disorder caused by the human immunodeficiency virus (HIV), but it can also affect the nervous system. HIV does not appear to directly invade nerve cells but it jeopardizes their health and function, causing symptoms such as confusion, forgetfulness, behavioral changes, headaches, progressive weakness and loss of sensation in the arms and legs, cognitive motor impairment, or damage to the peripheral nerves. Other complications that can occur as a result of HIV infection or the drugs used to treat it include pain, seizures, shingles, spinal cord problems, lack of coordination, difficult or painful swallowing, anxiety disorder, depression, fever, vision loss, gait disorders, destruction of brain tissue, and coma. Other AIDS-related nervous system disorders may be caused by certain cancers or by illnesses that would not otherwise affect people with healthy immune systems.
                
Among the most common neurological complications are: AIDS dementia complex, causing symptoms such as encephalitis (inflammation of the brain), behavioral changes, and a gradual decline in cognitive function; central nervous system lymphomas, cancerous tumors that either begin in the brain or result from a cancer that has spread from another site in the body; cryptococcal meningitis; cytomegalovirus infections; herpes virus infections; neuropathy; neurosyphilis; progressive multifocal leukoencephalopathy (PML); and psychological and neuropsychiatric disorders.
No single treatment can cure the neurological complications of AIDS. Some disorders require aggressive therapy while others are treated symptomatically.
                
Medicines range from analgesics sold over the counter to antiepileptic drugs, opiates, corticosteroids, and some classes of antidepressants. Other treatments include radiation therapy or chemotherapy to kill or shrink cancerous brain tumors that may be caused by HIV, antifungal or antimalarial drugs to combat certain bacterial infections, and penicillin to treat neurosyphilis. Aggressive antiretroviral therapy is used to treat AIDS dementia complex, PML, and cytomegalovirus encephalitis. HAART, or highly active antiretroviral therapy, combines at least three drugs to reduce the amount of virus circulating in the blood and may also delay the start of some infections.
Tabes dorsalis is a slow degeneration of the nerve cells and nerve fibers that carry sensory information to the brain. The degenerating nerves are in the dorsal columns of the spinal cord (the portion closest to the back of the body) and carry information that help maintain a person's sense of position. Tabes dorsalis is the result of an untreated syphilis infection. Symptoms may not appear for some decades after the initial infection and include weakness, diminished reflexes, unsteady gait, progressive degeneration of the joints, loss of coordination, episodes of intense pain and disturbed sensation, personality changes, dementia, deafness, visual impairment, and impaired response to light. The disease is more frequent in males than in females. Onset is commonly during mid-life. The incidence of tabes dorsalis is rising, in part due to co-associated HIV infection.
Herpes zoster oticus, also called Ramsay Hunt Syndrome or Ramsay Hunt Syndrome type II, is a common complication of shingles. Shingles is an infection caused by the varicella-zoster virus, which is the virus that causes chickenpox. Shingles occurs in people who have had chickenpox and represents a reactivation of the dormant varicella-zoster virus. Herpes zoster oticus, which is caused by the spread of the varicella-zoster virus to facial nerves, is characterized by intense ear pain, a rash around the ear, mouth, face, neck, and scalp, and paralysis of facial nerves. Other symptoms may include hearing loss, vertigo (abnormal sensation of movement), and tinnitus (abnormal sounds). Taste loss in the tongue and dry mouth and eyes may also occur.
Hemicrania continua is a chronic and persistent form of headache marked by continuous pain that varies in severity, always occurs on the same side of the face and head, and is superimposed with additional debilitating symptoms. on the continuous but fluctuating pain are occasional attacks of more severe pain. A small percentage of individuals with hemicrania continua have bilateral pain, or pain on both sides of the head. A headache is considered hemicrania continua if the person has had a one-sided daily or continuous headache of moderate intensity with occasional short, piercing head pain for more than 3 months without shifting sides or pain-free periods. The headache must also be completely responsive to treatment with the non-steroidal anti-inflammatory drug drug indomethacin. It must have at least one of the following symptoms: eye redness and/or tearing, nasal congestion and/or runny nose, ptosis (drooping eyelid) and miosis (contracture of the iris). Occasionally, individuals will also have forehead sweating and migraine symptoms, such as throbbing pain, nausea and/or vomiting, or sensitivity to light and sound. The disorder has two forms: chronic, with daily headaches, and remitting, in which headaches may occur for a period as long as 6 months and are followed by a pain-free period of weeks to months until the pain returns. Most patients experience attacks of increased pain three to five times per 24-hour cycle. This disorder is more common in women than in men. Physical exertion and alcohol use may increase the severity of headache pain in some patients. The cause of this disorder is unknown.
Indomethacin provides rapid relief from symptoms. Patients must take between 25 and 300 milligrams of indomethacin daily and indefinitely to decrease symptoms. Some individuals may need to take acid-suppression medicine due to a gastrointestinal side effect. For those who cannot tolerate the side effects, another NSAID, celecoxib, has been shown to have less complications and can be prescribed. Amitriptyline and other tricyclic antidepressants are also effective in some individuals with hemicrania continua as a preventative treatment.
Paroxysmal choreoathetosis is a movement disorder characterized by episodes or attacks of involuntary movements of the limbs, trunk, and facial muscles. The disorder may occur in several members of a family, or in only a single family member. Prior to an attack some individuals experience tightening of muscles or other physical symptoms. Involuntary movements precipitate some attacks, and other attacks occur when the individual has consumed alcohol or caffeine, or is tired or stressed. Attacks can last from 10 seconds to over an hour. Some individuals have lingering muscle tightness after an attack. Paroxysmal choreoathetosis frequently begins in early adolescence. A gene associated with the disorder has been discovered. The same gene is also associated with epilepsy.
For several decades the term tropical spastic paraparesis (TSP) has been used to describe a chronic and progressive disease of the nervous system that affects adults living in equatorial areas of the world and causes progressive weakness, stiff muscles, muscle spasms, sensory disturbance, and sphincter dysfunction. The cause of TSP was obscure until the mid-1980s, when an important association was established between the human retrovirus  human T-cell lymphotrophic virus type 1 (also known as HTLV-1)  and TSP. TSP is now called HTLV-1 associated myelopathy/ tropical spastic paraparesis or HAM/TSP. The HTLV-1 retrovirus is thought to cause at least 80 percent of the cases of HAM/TSP by impairing the immune system. In addition to neurological symptoms of weakness and muscle stiffness or spasms, in rare cases individuals with HAM/TSP also exhibit uveitis (inflammation of the uveal tract of the eye), arthritis (inflammation of one or more joints), pulmonary lymphocytic alveolitis (inflammation of the lung), polymyositis (an inflammatory muscle disease), keratoconjunctivitis sicca (persistent dryness of the cornea and conjunctiva), and infectious dermatitis (inflammation of the skin). The other serious complication of HTLV-1 infection is the development of adult T-cell leukemia or lymphoma. Nervous system and blood-related complications occur only in a very small proportion of infected individuals, while most remain largely without symptoms throughout their lives.
                
The HTLV-1 virus is transmitted person-to-person via infected cells: breast-feeding by mothers who are seropositive (in other words, have high levels of virus antibodies in their blood), sharing infected needles during intravenous drug use, or having sexual relations with a seropositive partner. Less than 2 percent of HTLV-1 seropositive carriers will become HAM/TSP patients.
Alpers' disease is a progressive, neurodevelopmental, mitochondrial DNA depletion syndrome characterized by three co-occurring clinical symptoms: psychomotor regression (dementia); seizures; and liver disease. It is an autosomal recessive disease caused by mutation in the gene for the mitochondrial DNA polymerase POLG. The disease occurs in about one in 100,000 persons. Most individuals with Alpers' disease do not show symptoms at birth and develop normally for weeks to years before the onset of symptoms. Diagnosis is established by testing for the POLG gene. Symptoms typically occur months before tissue samples show the mitochondrial DNA depletion, so that these depletion studies cannot be used for early diagnosis. About 80 percent of individuals with Alpers' disease develop symptoms in the first two years of life, and 20 percent develop symptoms between ages 2 and 25. The first symptoms of the disorder are usually nonspecific and may include hypoglycemia secondary to underlying liver disease, failure to thrive, infection-associated encephalopathy, spasticity, myoclonus (involuntary jerking of a muscle or group of muscles), seizures, or liver failure. An increased protein level is seen in cerebrospinal fluid analysis. Cortical blindness (loss of vision due to damage to the area of the cortex that controls vision) develops in about 25 percent of cases. Gastrointestinal dysfunction and cardiomyopathy may occur. Dementia is typically episodic and often associated with an infection that occurs while another disease is in process. Seizures may be difficult to control and unrelenting seizures can cause developmental regression as well. "Alpers-like" disorders without liver disease are genetically different and have a different clinical course. Fewer than one-third of individuals with the "Alpers-like" phenotype without liver disease have POLG mutations.
There is no cure for Alpers' disease and no way to slow its progression. Treatment is symptomatic and supportive. Anticonvulsants may be used to treat the seizures, but at times the seizures do not respond well to therapy, even at high doses. Therefore, the benefit of seizure control should be weights against what could be excessive sedation from the anticonvulsant.. Valproate should not be used since it can increase the risk of liver failure. Physical therapy may help to relieve spasticity and maintain or increase muscle tone.
Myasthenia gravis is a chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal (voluntary) muscles of the body. Symptoms vary in type and intensity. The hallmark of myasthenia gravis is muscle weakness that increases during periods of activity and improves after periods of rest. Muscles that control eye and eyelid movements, facial expression, chewing, talking, and swallowing are often, but not always, involved. The muscles that control breathing and neck and limb movements may also be affected. Myasthenia gravis is caused by a defect in the transmission of nerve impulses to muscles. Normally when impulses travel down the nerve, the nerve endings release a neurotransmitter substance called acetylcholine. In myasthenia gravis, antibodies produced by the body's own immune system block, alter, or destroy the receptors for acetylcholine. The first noticeable symptoms of myasthenia gravis may be weakness of the eye muscles, difficulty in swallowing, or slurred speech. Myasthenia gravis is an autoimmune disease because the immune system--which normally protects the body from foreign organisms--mistakenly attacks itself.. It is not directly inherited nor is it contagious.
Myasthenia gravis can be controlled. Some medications improve neuromuscular transmission and increase muscle strength, and some suppress the production of abnormal antibodies. These medications must be used with careful medical follow up because they may cause major side effects. Thymectomy, the surgical removal of the thymus gland (which often is abnormal in those with myasthenia gravis), improves symptoms in certain individuals Other therapies include plasmapheresis, a procedure in which abnormal antibodies are removed from the blood, and high-dose intravenous immune globulin, which temporarily modifies the immune system and provides the body with normal antibodies from donated blood.
Scientists are evaluating new and improving current treatments for myasthenia gravis. Different drugs are being tested, either alone or in combination with existing drug therapies, to see if they are effective in treating the disorder. One study seeks to understand the molecular basis of synaptic transmission in the nervous system. Thymectomy is being studied in individuals who do not have thymoma, to assess long-term benefit the surgery may have over medical therapy alone. And investigators are examining the safety and efficacy of autologous hematopoietic stem cell transplantation to treat refractory and severe myasthenia gravis.
Spinal Muscular Atrophy (SMA) Types I, II, and III belong to a group of hereditary diseases that cause weakness and wasting of the voluntary muscles in the arms and legs of infants and children. The disorders are caused by an abnormal or missing gene known as the survival motor neuron gene 1 (SMN1), which is responsible for the production of a protein essential to motor neurons. Without this protein, lower motor neurons in the spinal cord degenerate and die. The type of SMA (I, II, or III) is determined by the age of onset and the severity of symptoms. Type I (also known as Werdnig-Hoffman disease, or infantile-onset SMA) is evident at birth or within the first few months. Symptoms include floppy limbs and trunk, feeble movements of the arms and legs, swallowing and feeding difficulties, and impaired breathing. Type II (the intermediate form) usually begins 6 and 18 months of age. Legs tend to be more impaired than arms. Children with Type II may able to sit and some may be able to stand or walk with help. Symptoms of Type III (also called Kugelberg-Welander disease) appear between 2 and 17 years of age and include difficulty running, climbing steps, or rising from a chair. The lower extremities are most often affected. Complications include scoliosis and chronic shortening of muscles or tendons around joints.