Limbic Encephalitis
Encephalitis
Paraneoplastic Syndromes, Nervous System
Isaacs Syndrome
Paraneoplastic Syndromes
Encephalitis, Viral
Encephalitis, Herpes Simplex
Encephalitis, Japanese
Encephalitis Virus, Japanese
Confusion
Paraneoplastic Polyneuropathy
Syringomyelia
Autoantibodies
Limbic System
Potassium Channels, Voltage-Gated
Encephalitis, Arbovirus
Encephalitis Virus, Venezuelan Equine
Encephalitis, St. Louis
Encephalitis Viruses
Encephalitis Virus, St. Louis
Magnetic Resonance Imaging
Amnesia
Japanese Encephalitis Vaccines
Encephalitis Virus, Eastern Equine
Limbic encephalitis and hyperactive foci on PET scan. (1/70)
Two cases of patients with paraneoplastic limbic encephalitis, difficult to control seizures, and unilateral hippocampal hypermetabolism on positron emission tomography (PET) are described. Two women aged 33 and 61 presented with uncontrolled complex partial seizures, profound memory loss and cognitive decline. One was later diagnosed with breast cancer and the other with lung cancer. Video-EEG on the first patient recorded multifocal sharp waves and bilateral independent seizure onsets. The second patient had no epileptiform discharges and bitemporal ictal onset, even though the clinical seizures suggested a right temporal onset. Magnetic resonance imaging (MRI) was normal in both patients. PET scans obtained in the interictal state showed right hippocampal hypermetabolism in both patients. In the second patient, the lung cancer was irradiated with resolution of seizures and improvement of memory function. A PET scan six months later was normal. Subsequent seizure recurrence and worsening of memory led to the discovery of widespread metastases. Limbic encephalitis should be considered in the differential diagnosis of intractable partial epilepsy, particularly if accompanied by severe memory loss and cognitive decline. Treatment of the underlying cancer may be lead to improved seizure control. Hippocampal hypermetabolism may be a common feature on PET, and may indicate subclinical seizure activity. (+info)Paraneoplastic limbic encephalitis: neurological symptoms, immunological findings and tumour association in 50 patients. (2/70)
Paraneoplastic limbic encephalitis (PLE) is a rare disorder characterized by personality changes, irritability, depression, seizures, memory loss and sometimes dementia. The diagnosis is difficult because clinical markers are often lacking, and symptoms usually precede the diagnosis of cancer or mimic other complications. The frequency of antineuronal antibodies in patients with PLE has not been investigated. We examined the neurological symptoms and the causal tumours in 50 patients with PLE to determine the utility of paraneoplastic antibodies and other tests. The diagnosis of PLE required neuropathological examination or the presence of the four following criteria: (i) a compatible clinical picture; (ii) an interval of <4 years between the development of neurological symptoms and tumour diagnosis; (iii) exclusion of other neuro-oncological complications; and (iv) at least one of the following: CSF with inflammatory changes but negative cytology; MRI demonstrating temporal lobe abnormalities; EEG showing epileptic activity in the temporal lobes. Of 1047 patients with neurological symptoms, whose sera or CSF were examined for paraneoplastic antibodies, 79 had the presumptive diagnosis of limbic encephalitis, dementia, cognitive dysfunction, or confusion. Fifty of these patients fulfilled our criteria for PLE. Pathological confirmation was obtained in 12 patients. The commonly associated neoplasms were of the lung (50%), testis (20%) and breast (8%). Neurological symptoms preceded the cancer diagnosis in 60% of patients (by a median of 3.5 months). Twenty-five of 44 (57%) patients with MRI studies had signal abnormalities in the limbic system. Thirty (60%) patients had antineuronal antibodies (18 anti-Hu, 10 anti-Ta, 2 anti-Ma), and 20 were antibody-negative or had uncharacterized antibodies (n = 4). The combination of symptoms, MRI findings and paraneoplastic antibodies established the diagnosis of PLE in 78% of the patients. Patients with anti-Hu antibodies usually had small-cell lung cancer (94%), multifocal neurological symptoms (78%) and a poor neurological outcome. Patients with anti-Ta (also called anti-Ma2) antibodies were young men with testicular tumours (100%), frequent hypothalamic involvement (70%) and a poor neurological outcome. In the group of patients without anti-Hu or anti-Ta antibodies, the tumour distribution was diverse, with cancer of the lung the most common (36%); 57% had positive MRI. Fifteen of 34 (44%) patients with a median follow-up of 8 months showed neurological improvement. Treatment of the tumour appeared to have more effect on the neurological outcome than the use of immune modulation. Improvement was observed in 38% of anti-Hu patients, 30% of anti-Ta patients and 64% of patients without these antibodies. (+info)Limbic encephalitis and antibodies to Ma2: a paraneoplastic presentation of breast cancer. (3/70)
A patient with atypical medullary breast cancer is described who presented with symptoms of limbic encephalitis. The patient's serum and CSF contained antibodies that reacted with the nervous system and the tumour. These antibodies recognised Ma2, a neuronal protein related to paraneoplastic limbic and brainstem encephalitis in men with testicular tumours. This report highlights the importance of testing for paraneoplastic antineuronal antibodies in cases of unexplained limbic encephalitis and suggests screening for breast cancer in women with antibodies predominantly directed to Ma2. (+info)Memory lost, memory regained: neuropsychological findings and neuroimaging in two cases of paraneoplastic limbic encephalitis with radically different outcomes. (4/70)
OBJECTIVE: To report two cases of paraneoplastic limbic encephalitis (PNLE) with similar clinical presentation, but dramatically different outcome and to highlight the role of neuropsychological and radiological evaluation in PNLE. METHODS: Both patients underwent an extensive battery of neuropsychological tests designed to document general intellectual function, anterograde verbal and visual memory, naming, knowledge and executive ability. In addition, structural (CT and MRI) and functional (HMPAO-SPECT) brain scans were performed. RESULTS: Both patients presented with fairly sudden onset of profound and persistent memory loss in the absence of other neurological symptoms. Their subsequently diagnosed small cell lung cancer was treated with a combination of radiotherapy and chemotherapy, leading to remission of the tumour. The memory of patient 1 recovered fully and he died from an unrelated cause 1 year later; neuropsychological testing showed a severe, but isolated, anterograde amnesia, brain MRI was normal and HMPAO-SPECT showed left medial temporal hypoperfusion. Patient 2 remained densely amnesic despite regression of her lung tumour; neuropsychological testing disclosed both anterograde and extensive retrograde amnesia together with more generalised cognitive deficits including anomia and executive impairments, MRI showed gross atrophy of the hippocampus and amygdala bilaterally, and HMPAO-SPECT showed pronounced frontal and temporal hypoperfusion. CONCLUSION: Complete remission from PNLE may occur and seems to be associated with pure anterograde amnesia without evidence of structural hippocampal damage in MRI. By contrast, cognitive deficits beyond severe anterograde amnesia and evidence of destructive medial temporal lobe pathology on MRI seem to be poor prognostic features. (+info)Paraneoplastic limbic encephalitis associated with bronchogenic carcinoma: a case report. (5/70)
Paraneoplastic limbic encephalitis is a rare clinical entity, associated most often with the oat cell carcinoma of the lung. Clinically, it presents with affective changes in personality, memory loss, confusional state, hallucinations, and seizures; with dementia being the common feature as the disorder progresses. Response to treatment is disappointingly poor. (+info)Limbic encephalitis presenting with topographical disorientation and amnesia. (6/70)
A case of paraneoplastic limbic encephalitis presenting with topographical disorientation is reported. A 70 year old woman became unable to identify familiar buildings and landscapes and could not recall the way to destinations she had known very well for years. She also showed attentional disturbance and severe anterograde amnesia. Her retrograde amnesia extended for one year at most. No other neuropsychological deficits were noted. Thus her topographical disorientation was of the primary form. Specific tests related to topographical disorientation showed that her two main symptoms seem to fall into the categories of landscape agnosia and heading disorientation. T2 weighted magnetic resonance imaging revealed high intensity signals in the anteromedial temporal lobes bilaterally, in the right posterior parahippocampal gyrus, in the right retrosplenial region, and in the right inferior precuneus. Anti-Hu antibody was found in the serum. This case shows that topographical disorientation can be a primary symptom of limbic encephalitis. (+info)MR imaging of autopsy-proved paraneoplastic limbic encephalitis in non-Hodgkin lymphoma. (7/70)
We report the case of a 26-year-old man with precursor T-cell acute lymphoblastic leukemia who developed paraneoplastic limbic encephalitis that was diagnosed on the basis of MR imaging findings and was proved post mortem. In our MR imaging studies, fluid-attenuated inversion recovery images and diffusion-weighted echo-planar images clearly depicted bilateral involvement of the medial temporal lobes and multifocal involvement of the brain, whereas T2-weighted turbo spin-echo images failed to show the changes. (+info)Steroid-responsive limbic encephalitis. (8/70)
A 71-year-old man presented with gradually progressing cognitive decline following acute febrile exanthematous disorder. The MRI showed an abnormality in the bilateral limbic systems. An elevation of cerebrospinal fluid (CSF) protein with lymphocyte pleocytosis was noted. Immunoblot of the CSF revealed the presence of anti-white matter antibodies that mainly recognized astrocytes. Intravenous steroid followed by oral steroid reduced the symptoms to a remarkable degree. The patient has now been successfully sustained with steroid for more than two years. We considered that this case is classified as non-paraneoplastic limbic encephalitis, and acquired autoimmunity played a major role in the pathogenesis of this case. (+info)Limbic encephalitis is a rare type of inflammatory autoimmune disorder that affects the limbic system, which is a part of the brain involved in emotions, behavior, memory, and sense of smell. It is characterized by inflammation of the limbic system, leading to symptoms such as memory loss, confusion, seizures, changes in behavior and mood, and problems with autonomic functions.
Limbic encephalitis can be caused by a variety of factors, including viral infections, cancer, or autoimmune disorders. In some cases, the cause may remain unknown. Diagnosis typically involves a combination of clinical evaluation, imaging studies (such as MRI), and analysis of cerebrospinal fluid. Treatment usually involves immunosuppressive therapy to reduce inflammation, as well as addressing any underlying causes if they can be identified.
It is important to note that limbic encephalitis is a serious condition that requires prompt medical attention and treatment. If you or someone else experiences symptoms such as sudden confusion, memory loss, or seizures, it is essential to seek medical care immediately.
Encephalitis is defined as inflammation of the brain parenchyma, which is often caused by viral infections but can also be due to bacterial, fungal, or parasitic infections, autoimmune disorders, or exposure to toxins. The infection or inflammation can cause various symptoms such as headache, fever, confusion, seizures, and altered consciousness, ranging from mild symptoms to severe cases that can lead to brain damage, long-term disabilities, or even death.
The diagnosis of encephalitis typically involves a combination of clinical evaluation, imaging studies (such as MRI or CT scans), and laboratory tests (such as cerebrospinal fluid analysis). Treatment may include antiviral medications, corticosteroids, immunoglobulins, and supportive care to manage symptoms and prevent complications.
Paraneoplastic syndromes of the nervous system are a group of rare disorders that occur in some individuals with cancer. These syndromes are caused by an immune system response to the cancer tumor, which can lead to the damage or destruction of nerve cells. The immune system produces antibodies and/or activated immune cells that attack the neural tissue, leading to neurological symptoms.
Paraneoplastic syndromes can affect any part of the nervous system, including the brain, spinal cord, peripheral nerves, and muscles. Symptoms vary depending on the specific syndrome and the location of the affected nerve tissue. Some common neurological symptoms include muscle weakness, numbness or tingling, seizures, memory loss, confusion, difficulty speaking or swallowing, visual disturbances, and coordination problems.
Paraneoplastic syndromes are often associated with specific types of cancer, such as small cell lung cancer, breast cancer, ovarian cancer, and lymphoma. Diagnosis can be challenging because the symptoms may precede the discovery of the underlying cancer. A combination of clinical evaluation, imaging studies, laboratory tests, and sometimes a brain biopsy may be necessary to confirm the diagnosis.
Treatment typically involves addressing the underlying cancer with surgery, chemotherapy, or radiation therapy. Immunosuppressive therapies may also be used to manage the immune response that is causing the neurological symptoms. While treatment can help alleviate symptoms and improve quality of life, paraneoplastic syndromes are often difficult to cure completely.
Isaac's syndrome, also known as neuromyotonia, is a rare neurological disorder characterized by continuous muscle fiber activity leading to stiffness, cramps, and delayed relaxation after contraction. This condition results from hyperexcitability of the peripheral nerves due to dysfunction of voltage-gated potassium channels.
The symptoms may include:
1. Muscle stiffness (rigidity)
2. Muscle twitching or cramping (myokymia)
3. Delayed relaxation after contraction (percussion myotonia)
4. Involuntary muscle activity (neuromyotonia)
5. Hyperhidrosis (excessive sweating)
6. Paresthesias (abnormal sensations)
Isaac's syndrome can be associated with other conditions, such as autoimmune disorders, paraneoplastic syndromes, or genetic factors. The diagnosis typically involves clinical examination, electromyography (EMG), and nerve conduction studies. Treatment options may include medications that reduce neuronal excitability, such as anticonvulsants, plasma exchange, or intravenous immunoglobulin therapy.
Paraneoplastic syndromes refer to a group of rare disorders that are caused by an abnormal immune system response to a cancerous (malignant) tumor. These syndromes are characterized by symptoms or signs that do not result directly from the growth of the tumor itself, but rather from substances produced by the tumor or the body's immune system in response to the tumor.
Paraneoplastic syndromes can affect various organs and systems in the body, including the nervous system, endocrine system, skin, and joints. Examples of paraneoplastic syndromes include Lambert-Eaton myasthenic syndrome (LEMS), which affects nerve function and causes muscle weakness; cerebellar degeneration, which can cause difficulty with coordination and balance; and dermatomyositis, which is an inflammatory condition that affects the skin and muscles.
Paraneoplastic syndromes can occur in association with a variety of different types of cancer, including lung cancer, breast cancer, ovarian cancer, and lymphoma. Treatment typically involves addressing the underlying cancer, as well as managing the symptoms of the paraneoplastic syndrome.
Viral encephalitis is a medical condition characterized by inflammation of the brain caused by a viral infection. The infection can be caused by various types of viruses, such as herpes simplex virus, enteroviruses, arboviruses (transmitted through insect bites), or HIV.
The symptoms of viral encephalitis may include fever, headache, stiff neck, confusion, seizures, and altered level of consciousness. In severe cases, it can lead to brain damage, coma, or even death. The diagnosis is usually made based on clinical presentation, laboratory tests, and imaging studies such as MRI or CT scan. Treatment typically involves antiviral medications, supportive care, and management of complications.
Herpes simplex encephalitis (HSE) is a severe and potentially life-thingening inflammation of the brain caused by the herpes simplex virus (HSV), most commonly HSV-1. It is a rare but serious condition that can cause significant neurological damage if left untreated.
The infection typically begins in the temporal or frontal lobes of the brain and can spread to other areas, causing symptoms such as headache, fever, seizures, confusion, memory loss, and personality changes. In severe cases, it can lead to coma or death.
Diagnosis of HSE is often made through a combination of clinical presentation, imaging studies (such as MRI), and laboratory tests, including polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) to detect the presence of the virus.
Treatment typically involves antiviral medications, such as acyclovir, which can help reduce the severity of the infection and prevent further neurological damage. In some cases, corticosteroids may also be used to reduce inflammation in the brain. Prompt treatment is critical for improving outcomes and reducing the risk of long-term neurological complications.
Japanese encephalitis is a viral inflammation of the brain (encephalitis) caused by the Japanese encephalitis virus (JEV). It is transmitted to humans through the bite of infected Culex mosquitoes, particularly in rural and agricultural areas. The majority of JE cases occur in children under the age of 15. Most people infected with JEV do not develop symptoms, but some may experience mild symptoms such as fever, headache, and vomiting. In severe cases, JEV can cause high fever, neck stiffness, seizures, confusion, and coma. There is no specific treatment for Japanese encephalitis, and care is focused on managing symptoms and supporting the patient's overall health. Prevention measures include vaccination and avoiding mosquito bites in endemic areas.
Japanese Encephalitis Virus (JEV) is a type of flavivirus that is the causative agent of Japanese encephalitis, a mosquito-borne viral infection of the brain. The virus is primarily transmitted to humans through the bite of infected Culex species mosquitoes, particularly Culex tritaeniorhynchus and Culex gelidus.
JEV is endemic in many parts of Asia, including China, Japan, Korea, India, Nepal, Thailand, and Vietnam. It is estimated to cause around 68,000 clinical cases and 13,000-20,000 deaths each year. The virus is maintained in a transmission cycle between mosquitoes and vertebrate hosts, primarily pigs and wading birds.
Most JEV infections are asymptomatic or result in mild symptoms such as fever, headache, and muscle aches. However, in some cases, the infection can progress to severe encephalitis, which is characterized by inflammation of the brain, leading to neurological symptoms such as seizures, tremors, paralysis, and coma. The case fatality rate for Japanese encephalitis is estimated to be 20-30%, and around half of those who survive have significant long-term neurological sequelae.
Prevention of JEV infection includes the use of insect repellent, wearing protective clothing, and avoiding outdoor activities during peak mosquito feeding times. Vaccination is also an effective means of preventing Japanese encephalitis, and vaccines are available for travelers to endemic areas as well as for residents of those areas.
Confusion is a state of bewilderment or disorientation in which a person has difficulty processing information, understanding their surroundings, and making clear decisions. It can be caused by various medical conditions such as infections, brain injury, stroke, dementia, alcohol or drug intoxication or withdrawal, and certain medications. Confusion can also occur in older adults due to age-related changes in the brain.
In medical terms, confusion is often referred to as "acute confusional state" or "delirium." It is characterized by symptoms such as difficulty paying attention, memory loss, disorientation, hallucinations, and delusions. Confusion can be a serious medical condition that requires immediate evaluation and treatment by a healthcare professional.
Paraneoplastic polyneuropathy is a rare neurological disorder that can occur in some individuals with cancer. It's caused by the immune system producing antibodies or cells that attack the nervous system (neurons, nerve axons, or myelin sheath) as a response to the presence of a tumor or cancer in the body.
The term "polyneuropathy" refers to damage or dysfunction affecting multiple peripheral nerves simultaneously. This can lead to various symptoms such as numbness, tingling, muscle weakness, and pain, typically starting in the hands and feet and progressing upwards.
In paraneoplastic polyneuropathy, these symptoms are related to the immune system's response to the cancer rather than direct invasion of the nerves by the tumor itself. The specific type of polyneuropathy can vary between individuals, and it may present as sensorimotor polyneuropathy, autonomic neuropathy, or a combination of both.
Early diagnosis and treatment of the underlying cancer are crucial for managing paraneoplastic polyneuropathy. Immunotherapy, plasma exchange, and intravenous immunoglobulin may be used to help control the immune response and alleviate symptoms.
Syringomyelia is a medical condition characterized by the formation of a fluid-filled cavity or cavities (syrinx) within the spinal cord. This syrinx can lead to various symptoms depending on its size and location, which may include pain, muscle weakness, numbness, and stiffness in the neck, back, shoulders, arms, or legs. In some cases, it may also affect bladder and bowel function, sexual performance, and the ability to maintain normal body temperature. Syringomyelia is often associated with Chiari malformation, a condition where the lower part of the brain extends into the spinal canal. However, other conditions such as spinal cord injuries, tumors, or infections may also cause syringomyelia.
Autoantibodies are defined as antibodies that are produced by the immune system and target the body's own cells, tissues, or organs. These antibodies mistakenly identify certain proteins or molecules in the body as foreign invaders and attack them, leading to an autoimmune response. Autoantibodies can be found in various autoimmune diseases such as rheumatoid arthritis, lupus, and thyroiditis. The presence of autoantibodies can also be used as a diagnostic marker for certain conditions.
The limbic system is a complex set of structures in the brain that includes the hippocampus, amygdala, fornix, cingulate gyrus, and other nearby areas. It's associated with emotional responses, instinctual behaviors, motivation, long-term memory formation, and olfaction (smell). The limbic system is also involved in the modulation of visceral functions and drives, such as hunger, thirst, and sexual drive.
The structures within the limbic system communicate with each other and with other parts of the brain, particularly the hypothalamus and the cortex, to regulate various physiological and psychological processes. Dysfunctions in the limbic system can lead to a range of neurological and psychiatric conditions, including depression, anxiety disorders, post-traumatic stress disorder (PTSD), and certain types of memory impairment.
Voltage-gated potassium channels are a type of ion channel found in the membrane of excitable cells such as nerve and muscle cells. They are called "voltage-gated" because their opening and closing is regulated by the voltage, or electrical potential, across the cell membrane. Specifically, these channels are activated when the membrane potential becomes more positive, a condition that occurs during the action potential of a neuron or muscle fiber.
When voltage-gated potassium channels open, they allow potassium ions (K+) to flow out of the cell down their electrochemical gradient. This outward flow of K+ ions helps to repolarize the membrane, bringing it back to its resting potential after an action potential has occurred. The precise timing and duration of the opening and closing of voltage-gated potassium channels is critical for the normal functioning of excitable cells, and abnormalities in these channels have been linked to a variety of diseases, including cardiac arrhythmias, epilepsy, and neurological disorders.
Arbovirus encephalitis is a type of encephalitis (inflammation of the brain) caused by a group of viruses that are transmitted through the bite of infected arthropods, such as mosquitoes or ticks. The term "arbovirus" stands for "arthropod-borne virus."
There are many different types of arboviruses that can cause encephalitis, including:
* La Crosse virus
* St. Louis encephalitis virus
* West Nile virus
* Eastern equine encephalitis virus
* Western equine encephalitis virus
* Venezuelan equine encephalitis virus
The symptoms of arbovirus encephalitis can vary, but may include fever, headache, stiff neck, seizures, confusion, and weakness. In severe cases, it can lead to coma or death. Treatment typically involves supportive care to manage symptoms, as there is no specific antiviral treatment for most types of arbovirus encephalitis. Prevention measures include avoiding mosquito and tick bites, using insect repellent, and eliminating standing water where mosquitoes breed.
Venezuelan Equine Encephalitis Virus (VEEV) is a type of alphavirus that can cause encephalitis (inflammation of the brain) in horses and humans. It is primarily transmitted through the bite of infected mosquitoes, although it can also be spread through contact with contaminated food or water, or by aerosolization during laboratory work or in bioterrorism attacks.
VEEV infection can cause a range of symptoms in humans, from mild flu-like illness to severe encephalitis, which may result in permanent neurological damage or death. There are several subtypes of VEEV, some of which are more virulent than others. The virus is endemic in parts of Central and South America, but outbreaks can also occur in other regions, including the United States.
VEEV is considered a potential bioterrorism agent due to its ease of transmission through aerosolization and its high virulence. There are no specific treatments for VEEV infection, although supportive care can help manage symptoms. Prevention measures include avoiding mosquito bites in endemic areas, using personal protective equipment during laboratory work with the virus, and implementing strict biocontainment procedures in research settings.
St. Louis Encephalitis (SLE) is a type of viral brain inflammation caused by the St. Louis Encephalitis virus. It is transmitted to humans through the bite of infected mosquitoes, primarily Culex species. The virus breeds in warm, stagnant water and is more prevalent in rural and suburban areas.
Most people infected with SLE virus do not develop symptoms or only experience mild flu-like illness. However, some individuals, particularly the elderly, can develop severe illness characterized by sudden onset of fever, headache, neck stiffness, disorientation, coma, seizures, and spastic paralysis. There is no specific treatment for SLE, and management is focused on supportive care, including hydration, respiratory support, and prevention of secondary infections. Vaccination against SLE is not available, and prevention measures include using insect repellent, wearing protective clothing, and eliminating standing water around homes to reduce mosquito breeding sites.
Encephalitis viruses are a group of viruses that can cause encephalitis, which is an inflammation of the brain. Some of the most common encephalitis viruses include:
1. Herpes simplex virus (HSV) type 1 and 2: These viruses are best known for causing cold sores and genital herpes, but they can also cause encephalitis, particularly in newborns and individuals with weakened immune systems.
2. Varicella-zoster virus (VZV): This virus causes chickenpox and shingles, and it can also lead to encephalitis, especially in people who have had chickenpox.
3. Enteroviruses: These viruses are often responsible for summertime meningitis outbreaks and can occasionally cause encephalitis.
4. Arboviruses: These viruses are transmitted through the bites of infected mosquitoes, ticks, or other insects. Examples include West Nile virus, St. Louis encephalitis virus, Eastern equine encephalitis virus, and Western equine encephalitis virus.
5. Rabies virus: This virus is transmitted through the bite of an infected animal and can cause encephalitis in its later stages.
6. Measles virus: Although rare in developed countries due to vaccination, measles can still cause encephalitis as a complication of the infection.
7. Mumps virus: Like measles, mumps is preventable through vaccination, but it can also lead to encephalitis as a rare complication.
8. Cytomegalovirus (CMV): This virus is a member of the herpesvirus family and can cause encephalitis in people with weakened immune systems, such as those with HIV/AIDS or organ transplant recipients.
9. La Crosse virus: This arbovirus is primarily transmitted through the bites of infected eastern treehole mosquitoes and mainly affects children.
10. Powassan virus: Another arbovirus, Powassan virus is transmitted through the bites of infected black-legged ticks (also known as deer ticks) and can cause severe encephalitis.
It's important to note that many of these viruses are preventable through vaccination or by avoiding exposure to infected animals or mosquitoes. If you suspect you may have been exposed to one of these viruses, consult a healthcare professional for proper diagnosis and treatment.
St. Louis Encephalitis Virus (SLEV) is a type of arbovirus (arthropod-borne virus) from the family Flaviviridae and genus Flavivirus. It is the causative agent of St. Louis encephalitis (SLE), a viral disease characterized by inflammation of the brain (encephalitis). The virus is primarily transmitted to humans through the bite of infected mosquitoes, particularly Culex spp.
The SLEV infection in humans is often asymptomatic or may cause mild flu-like symptoms such as fever, headache, nausea, and vomiting. However, in some cases, the virus can invade the central nervous system, leading to severe neurological manifestations like meningitis, encephalitis, seizures, and even coma or death. The risk of severe disease increases in older adults and people with weakened immune systems.
There is no specific antiviral treatment for SLE; management typically focuses on supportive care to alleviate symptoms and address complications. Prevention measures include avoiding mosquito bites, using insect repellents, and eliminating breeding sites for mosquitoes. Vaccines are not available for SLEV, but they have been developed and tested in the past, with potential for future use in high-risk populations during outbreaks.
Medical Definition:
Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.
Amnesia is a condition characterized by memory loss, which can be temporary or permanent. It may result from brain damage or disease, and it can affect various aspects of memory, such as the ability to recall past events (retrograde amnesia), the ability to form new memories (anterograde amnesia), or both. Amnesia can also affect a person's sense of identity and their ability to learn new skills.
There are several types of amnesia, including:
1. Anterograde amnesia: This type of amnesia affects the ability to form new memories after an injury or trauma. People with anterograde amnesia may have difficulty learning new information and remembering recent events.
2. Retrograde amnesia: Retrograde amnesia affects the ability to recall memories that were formed before an injury or trauma. People with retrograde amnesia may have trouble remembering events, people, or facts from their past.
3. Transient global amnesia: This is a temporary form of amnesia that usually lasts for less than 24 hours. It is often caused by a lack of blood flow to the brain, and it can be triggered by emotional stress, physical exertion, or other factors.
4. Korsakoff's syndrome: This is a type of amnesia that is caused by alcohol abuse and malnutrition. It is characterized by severe memory loss, confusion, and disorientation.
5. Dissociative amnesia: This type of amnesia is caused by psychological factors, such as trauma or stress. People with dissociative amnesia may have trouble remembering important personal information or events that are emotionally charged.
The treatment for amnesia depends on the underlying cause. In some cases, memory may improve over time, while in other cases, it may be permanent. Treatment may involve medication, therapy, or rehabilitation to help people with amnesia cope with their memory loss and develop new skills to compensate for their memory impairments.
Japanese Encephalitis (JE) vaccines are immunobiological preparations used for active immunization against Japanese Encephalitis, a viral infection transmitted through the bite of infected mosquitoes. The vaccines contain inactivated or live attenuated strains of the JE virus. They work by stimulating the immune system to produce antibodies and T-cells that provide protection against the virus. There are several types of JE vaccines available, including inactivated Vero cell-derived vaccine, live attenuated SA14-14-2 vaccine, and inactivated mouse brain-derived vaccine. These vaccines have been shown to be effective in preventing JE and are recommended for use in individuals traveling to or living in areas where the disease is endemic.
Eastern equine encephalitis virus (EEEV) is a single-stranded RNA virus that belongs to the family Togaviridae and the genus Alphavirus. It is the causative agent of Eastern equine encephalitis (EEE), a rare but serious viral disease that can affect humans, horses, and some bird species.
EEEV is primarily transmitted through the bite of infected mosquitoes, particularly those belonging to the Culiseta and Coquillettidia genera. The virus is maintained in a transmission cycle between mosquitoes and wild birds, primarily passerine birds. Horses and humans are considered dead-end hosts, meaning they do not develop high enough levels of viremia to infect feeding mosquitoes and perpetuate the transmission cycle.
EEE is most commonly found in the eastern and Gulf Coast states of the United States, as well as in parts of Canada, Central and South America, and the Caribbean. The disease can cause severe neurological symptoms, including inflammation of the brain (encephalitis), meningitis, and neuritis. In severe cases, EEE can lead to seizures, coma, and death. There is no specific treatment for EEE, and prevention efforts focus on reducing mosquito populations and avoiding mosquito bites.