|
Videonystagmography
Videonystagmography (VNG) is a type of testing used to assess vestibular and central nervous system function through the use of eye movement tracking, specifically evaluating nystagmus. The older version of technology used to perform these tests, known as electronystagmography (ENG), leverages electrophysiological signals. There is a battery of tests which can be performed using this technology and testing, typically performed by an audiologist. These tests can be diagnostic in nature or used to monitor rehabilitation. The testing typically takes place in a dark or dimmed room with the patient laying or sitting, depending on the test, on a table or chair that can lean back to a flat position. The patient wears goggles containing a camera that tracks the pupils using infrared imaging; the video eye-tracking system records and sends pupil movement tracings to a computer typically with VNG analysis software. The goggles may also have a cover in order to deny vision for some tests while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nystagmus
Nystagmus is a condition of involuntary (or voluntary, in some cases) Eye movement (sensory), 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 visual impairment, reduced or limited vision. In normal eyesight, while the Human head, head rotates about an Axis of rotation, 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 nystagm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronystagmography
Electronystagmography (ENG) is a diagnostic test to record involuntary movements of the eye caused by a condition known as nystagmus. It can also be used to diagnose the cause of vertigo, dizziness or balance dysfunction by testing the vestibular system. Electronystagmography is used to assess voluntary and involuntary eye movements. It evaluates the cochlear nerve and the oculomotor nerve (CN III). The ENG can be used to determine the origin of various eye and ear disorders. Technique and results Electrodes applied around the eyes record eye movements using the corneo-retinal potential. Some portions of the ENG measure a patient's ability to track a moving stimuli while others observe the presence of nystagmus. The vestibular system monitors the position and movements of the head to stabilize retinal images. This information is integrated with the visual system and spinal afferents in the brain stem to produce the vestibulo-ocular reflex (VOR). ENG provides an objective asses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audiology
Audiology (from Latin 'to hear'; and from Ancient Greek, Greek branch of learning , ''wikt:-logia, -logia'') is a branch of science that studies hearing, balance, and related disorders. Audiologists treat those with hearing loss and proactively prevent related damage. By employing various testing strategies (e.g. behavioral hearing tests, otoacoustic emission measurements, and electrophysiologic tests), audiologists aim to determine whether someone has normal sensitivity to sounds. If hearing loss is identified, audiologists determine which portions of hearing (high, middle, or low frequencies) are affected, to what degree (severity of loss), and where the lesion causing the hearing loss is found (outer ear, middle ear, inner ear, auditory nerve and/or central nervous system). If an audiologist determines that a hearing loss or vestibular abnormality is present, they will provide recommendations for interventions or rehabilitation (e.g. hearing aids, cochlear implants, appropria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical complaint, affecting 20–30% of persons. Dizziness is broken down into four main subtypes: vertigo (~25–50%), equilibrioception#Dysfunction, disequilibrium (less than ~15%), presyncope (less than ~15%), and nonspecific dizziness (~10%). * Vertigo is the sensation of spinning or having one's surroundings spin about them. Many people find vertigo very disturbing and often report associated nausea and vomiting. * Presyncope describes lightheadedness or feeling faint; the name relates to Syncope (medicine), syncope, which is actually fainting. * equilibrioception#Dysfunction, Disequilibrium is the sensation of being off balance and is most often characterized by frequent falls in a specific direction. This condition is not of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benign Paroxysmal Positional Vertigo
Benign paroxysmal positional vertigo (BPPV) is a disorder arising from a problem in the inner ear. Symptoms are repeated, brief periods of vertigo with movement, characterized by a spinning sensation upon changes in the position of the head. * This can occur with turning in bed or changing position. Each episode of vertigo typically lasts less than one minute. Nausea is commonly associated. BPPV is one of the most common causes of vertigo. BPPV is a type of balance disorder along with labyrinthitis and Ménière's disease. It can result from a head injury or simply occur among those who are older. Often, a specific cause is not identified. When found, the underlying mechanism typically involves a small calcified otolith moving around loose in the inner ear. Diagnosis is typically made when the Dix–Hallpike test results in nystagmus (a specific movement pattern of the eyes) and other possible causes have been ruled out. In typical cases, medical imaging is not needed. BPPV ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Blood Pressure
Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is indicated by two numbers, the systolic blood pressure (the top number) and the diastolic blood pressure (the bottom number), which are the maximum and minimum blood pressures within the cardiac cycle, respectively. A systolic blood pressure of less than 90 millimeters of mercury (mmHg) or diastolic of less than 60 mmHg is generally considered to be hypotension. Different numbers apply to children. However, in practice, blood pressure is considered too low only if noticeable symptoms are present. Symptoms may include dizziness, lightheadedness, confusion, feeling tired, weakness, headache, blurred vision, nausea, neck or back pain, an irregular heartbeat or feeling that the heart is skipping beats or fluttering, sweating, and fain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anxiety
Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response to a present threat, whereas anxiety is the anticipation of a future one. It is often accompanied by nervous behavior such as pacing back and forth, Somatic anxiety, somatic complaints, and Rumination (psychology), rumination. Anxiety is a feeling of uneasiness and worry, usually generalized and unfocused as an overreaction to a situation that is only subjectively seen as menacing. It is often accompanied by muscular tension, restlessness, Fatigue (medical), fatigue, inability to catch one's breath, tightness in the abdominal region, nausea, and problems in concentration. Anxiety is closely related to fear, which is a response to a real or perceived immediate threat (fight-or-flight response); anxiety involves the expectation of a future t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caloric Reflex Testing
In medicine, the caloric reflex test (sometimes termed vestibular caloric stimulation) is a test of the vestibulo-ocular reflex that involves irrigating cold or warm water or air into the external auditory canal. This method was developed by Robert Bárány, who won a Nobel Prize in 1914 for this discovery. Utility The test is commonly used by physicians, audiologists and other trained professionals to validate a diagnosis of asymmetric function in the peripheral vestibular system. Calorics are usually a subtest of the electronystagmography (ENG) battery of tests. It is one of several tests which can be used to test for brain stem death. One novel use of this test has been to provide temporary pain relief from phantom limb pains in amputees and paraplegics. It can also induce a temporary remission of anosognosia, the visual and personal aspects of hemispatial neglect, hemianesthesia, and other consequences of right hemispheric damage. Technique and results Ice cold or warm wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
