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Opsoclonus
Opsoclonus refers to uncontrolled, irregular, and nonrhythmic eye movement. Opsoclonus consists of rapid, involuntary, multivectorial (horizontal and vertical), unpredictable, conjugate fast eye movements without inter-saccadic intervals. It is also referred to as saccadomania or reflexive saccade. The movements of opsoclonus may have a very small amplitude, appearing as tiny deviations from primary position. Possible causes of opsoclonus include neuroblastoma and encephalitis in children, and breast, lung, or ovarian cancer in adults. Other considerations include GLUT1 Deficiency Syndrome, multiple sclerosis, toxins, medication effects (e.g. Serotonin Syndrome), celiac disease, certain infections (West Nile virus, Lyme disease), non-Hodgkin lymphoma, and renal adenocarcinoma. It can also be caused by a lesion in the omnipause neurons which tonically inhibit initiation of saccadic eye movement (until signaled by the superior colliculus) by blocking paramedian pontine reticular fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opsoclonus Myoclonus Syndrome
Opsoclonus myoclonus syndrome (OMS), also known as opsoclonus-myoclonus-ataxia (OMA), is a rare neurological disease, disorder of unknown cause which appears to be the result of an autoimmune process involving the nervous system. It is an extremely rare condition, affecting as few as 1 in 10,000,000 people per year. It affects 2 to 3% of children with neuroblastoma and has been reported to occur with celiac disease and diseases of neurologic and autonomic dysfunction. Signs and symptoms Symptoms include: * opsoclonus (rapid, involuntary, multivectorial (horizontal and vertical), unpredictable, conjugate fast eye movements without intersaccadic [quick rotation of the eyes] intervals) * myoclonus (brief, involuntary twitching of a muscle or a group of muscles) * ataxia, cerebellar ataxia, both truncal and appendicular * aphasia (a language disorder in which there is an impairment of speech and of comprehension of speech, caused by brain damage) * mutism (a language disorder in which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroblastoma
Neuroblastoma (NB) is a type of cancer that forms in certain types of nerve tissue. It most frequently starts from one of the adrenal glands but can also develop in the head, neck, chest, abdomen, or Vertebral column, spine. Symptoms may include bone pain, a lump in the abdomen, neck, or chest, or a painless bluish lump under the skin. Typically, neuroblastoma occurs due to a genetic mutation occurring in the first trimester of pregnancy. Rarely, it may be due to a mutation heredity, inherited. Environmental factors have not been found to be involved. Diagnosis is based on a tissue biopsy. Occasionally, it may be found in a baby by ultrasound during pregnancy. At diagnosis, the cancer has usually already Metastasis, spread. The cancer is divided into low-, intermediate-, and high-risk groups based on a child's age, cancer stage, and what the cancer looks like. Treatment and outcomes depends on the risk group a person is in. Treatments may include observation, surgery, radiatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GLUT1 Deficiency
GLUT1 deficiency syndrome, also known as GLUT1-DS, De Vivo disease or Glucose transporter type 1 deficiency syndrome, is an autosomal dominant genetic metabolic disorder associated with a deficiency of GLUT1, the protein that transports glucose across the blood brain barrier. Glucose Transporter Type 1 Deficiency Syndrome has an estimated birth incidence of 1 in 90,000 to 1 in 24,300. This birth incidence translates to an estimated prevalence of 3,000 to 7,000 in the U.S. Presentation GLUT1 deficiency is characterized by an array of signs and symptoms including mental and motor developmental delays, infantile seizures refractory to anticonvulsants, ataxia, dystonia, dysarthria, opsoclonus, spasticity, other paroxysmal neurologic phenomena and sometimes deceleration of head growth also known as microcephaly. The presence and severity of symptoms vary considerably between affected individuals. Individuals with the disorder generally have frequent seizures (epilepsy), often beginni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocular Flutter
Ocular flutter is an opsoclonic disorder that results in horizontal saccades. It is caused by damage to the brainstem paramedian pontine reticular formation cells or the cerebellar neurons controlling those cells. See also * Nystagmus * Opsoclonus Opsoclonus refers to uncontrolled, irregular, and nonrhythmic eye movement. Opsoclonus consists of rapid, involuntary, multivectorial (horizontal and vertical), unpredictable, conjugate fast eye movements without inter-saccadic intervals. It is al ... References Vision {{Eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccade
In vision science, a saccade ( ; ; ) is a quick, simultaneous movement of both Eye movement (sensory), eyes between two or more phases of focal points in the same direction. In contrast, in Smooth pursuit, smooth-pursuit movements, the eyes move smoothly instead of in jumps. Controlled cortically by the frontal eye fields (FEF), or subcortically by the superior colliculus, saccades serve as a mechanism for focal points, rapid eye movement, and the fast phase of optokinetic reflex, optokinetic nystagmus. The word appears to have been coined in the 1880s by French ophthalmologist Louis Émile Javal, Émile Javal, who used a mirror on one side of a page to observe eye movement in silent reading, and found that it involves a succession of discontinuous individual movements. Function Humans and many organisms do not look at a scene in steadiness; instead, the eyes move around, locating interesting parts of the scene and building up a three-dimensional 'map' corresponding to the scen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathologic Nystagmus
Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. People can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision. In normal eyesight, while the head rotates about an axis, distant visual images are sustained by rotating eyes in the opposite direction of the respective axis. The semicircular canals in the vestibule of the ear sense angular acceleration, and send signals to the nuclei for eye movement in the brain. From here, a signal is relayed to the extraocular muscles to allow one's gaze to fix on an object as the head moves. Nystagmus occurs when the semicircular canals are stimulated (e.g., by means of the caloric test, or by disease) while the head is stationary. The direction of ocular movement is related to the semicircular canal that is being stimulated. There are two key forms of nystagmus: pathological and physiological, with variations within each type. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myoclonus
Myoclonus is a brief, involuntary, irregular (lacking rhythm) twitching of a muscle, a joint, or a group of muscles, different from clonus, which is rhythmic or regular. Myoclonus ( myo- "muscle", clonus "spasm") describes a medical sign and, generally, is not a diagnosis of a disease. It belongs to the hyperkinetic movement disorders, among tremor and chorea for example. These myoclonic twitches, jerks, or seizures are usually caused by sudden muscle contractions (''positive myoclonus'') or brief lapses of contraction (''negative myoclonus''). The most common circumstance under which they occur is while falling asleep ( hypnic jerk). Myoclonic jerks occur in healthy people and are experienced occasionally by everyone. However, when they appear with more persistence and become more widespread they can be a sign of various neurological disorders. Hiccups are a kind of myoclonic jerk specifically affecting the diaphragm. When a spasm is caused by another person it is kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Colliculus
In neuroanatomy, the superior colliculus () is a structure lying on the tectum, roof of the mammalian midbrain. In non-mammalian vertebrates, the Homology (biology), homologous structure is known as the optic tectum or optic lobe. The adjective form ''tectum, tectal'' is commonly used for both structures. In mammals, the superior colliculus forms a major component of the midbrain. It is a paired structure and together with the paired inferior colliculi forms the corpora quadrigemina. The superior colliculus is a layered structure, with a pattern that is similar in all mammals. The layers can be grouped into the superficial layers (retinal nerve fiber layer, stratum opticum and above) and the deeper remaining layers. Neurons in the superficial layers receive direct input from the retina and respond almost exclusively to visual stimuli. Many neurons in the deeper layers also respond to other modalities, and some respond to stimuli in multiple modalities. The deeper layers also conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychogenic Non-epileptic Seizures
Psychogenic non-epileptic seizures (PNES), also referred to as functional seizures or dissociative seizures, are episodes that resemble epileptic seizures but are not caused by abnormal electrical activity in the brain. Instead, they are classified as a type of functional neurological disorder (FND), in which symptoms arise from changes in brain function rather than structural disease or epilepsy. During a PNES episode, seizure-like behavior occurs in the absence of epileptiform activity on electroencephalogram (EEG). PNES can be difficult to distinguish from epileptic seizures based on clinical observation alone. Diagnosis is typically confirmed through video-EEG monitoring, which records both the clinical event and the absence of epileptiform activity. These episodes are involuntary and genuine, not consciously produced. Management primarily involves psychological treatment, particularly cognitive behavioral therapy (CBT). Outcomes vary and are influenced by factors such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiologic Nystagmus
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathological state'' refers to abnormal conditions, including human diseases. The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Because physiology focuses on the functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epilepsy
Epilepsy is a group of Non-communicable disease, non-communicable Neurological disorder, neurological disorders characterized by a tendency for recurrent, unprovoked Seizure, seizures. A seizure is a sudden burst of abnormal electrical activity in the brain that can cause a variety of symptoms, ranging from brief lapses of awareness or muscle jerks to prolonged convulsions. These episodes can result in physical injuries, either directly, such as broken bones, or through causing accidents. The diagnosis of epilepsy typically requires at least two unprovoked seizures occurring more than 24 hours apart. In some cases, however, it may be diagnosed after a single unprovoked seizure if clinical evidence suggests a high risk of recurrence. Isolated seizures that occur without recurrence risk or are provoked by identifiable causes are not considered indicative of epilepsy. The underlying cause is often unknown, but epilepsy can result from brain injury, stroke, infections, Brain tumor, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
