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Sensory Ataxia
Sensory ataxia is both a symptom and a sign in neurology. It is a form of ataxia (loss of coordination) caused not by cerebellar dysfunction but by loss of sensory input into the control of movement. Sensory ataxia is distinguished from cerebellar ataxia by the presence of near-normal coordination when the movement is visually observed by the patient, but marked worsening of coordination when the eyes are shut, indicating a positive Romberg's sign. Sensory ataxia also lacks the associated features of cerebellar ataxia such as pendular tendon reflexes, scanning dysarthria, nystagmus and broken pursuit eye movements. Patients with sensory ataxia often demonstrate pseudoathetosis and Romberg's sign. They usually complain of loss of balance in the dark, typically when closing their eyes in the shower or removing clothing over the head. __TOC__ Causes Sensory ataxia can be a manifestation of sensory large fiber peripheral neuropathies and conditions causing dysfunction of the dorsal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symptom
Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. 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 pains in the body, which occur as the body's immune system fights off an infection. Signs and symptoms Signs A medical sign is an objective observable indication of a disease, injury, or medical condition that may be detected during a physical examination. These signs may be visible, such as a rash or bruise, or otherwise detectable such as by using a stethoscope or taking blood pressure. Medical signs, along with symptoms, help in forming a diagnosis. Some examples of signs are nail clubbing of either the fingernail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Sign
Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. 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 pains in the body, which occur as the body's immune system fights off an infection. Signs and symptoms Signs A medical sign is an objective observable indication of a disease, injury, or medical condition that may be detected during a physical examination. These signs may be visible, such as a rash or bruise, or otherwise detectable such as by using a stethoscope or taking blood pressure. Medical signs, along with symptoms, help in forming a diagnosis. Some examples of signs are nail clubbing of either the fingernails o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ataxia
Ataxia (from Greek α- negative prefix+ -τάξις rder= "lack of order") is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements, that indicates dysfunction of parts of the nervous system that coordinate movement, such as the cerebellum. These nervous system dysfunctions occur in several different patterns, with different results and different possible causes. Ataxia can be limited to one side of the body, which is referred to as hemiataxia. Friedreich's ataxia has gait abnormality as the most commonly presented symptom. Dystaxia is a mild degree of ataxia. Types Cerebellar The term cerebellar ataxia is used to indicate ataxia due to dysfunction of the cerebellum. The cerebellum is responsible for integrating a significant amount of neural information that is used to coordinate smoothly ongoing movements and to participate in motor planning. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordination (physiology)
In physiology, motor coordination is the orchestrated movement of multiple body parts as required to accomplish intended motor skill, actions, like walking. This coordination is achieved by adjusting kinematic and Human kinetics, kinetic parameters associated with each body part involved in the intended movement. The modifications of these parameters typically relies on Sense, sensory feedback from one or more sensory modalities (see multisensory integration), such as proprioception and Visual perception, vision. Properties Large degrees of freedom Goal-directed and coordinated movement of body parts is inherently variable because there are many ways of coordinating body parts to achieve the intended movement goal. This is because the degrees of freedom (DOF) is large for most movements due to the many associated neuro-musculoskeletal elements.Bernstein N. (1967). The Coordination and Regulation of Movements. Pergamon Press. New York. Some examples of non-repeatable movements a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or even larger. In humans, the cerebellum plays an important role in motor control and cognition, cognitive functions such as attention and language as well as emotion, emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to motor coordination, coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in fine motor skill, fine movement, sense of balance, equilibrium, list of human positions, posture, and motor learning in humans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romberg's Sign
Romberg's test, Romberg's sign, or the Romberg maneuver is a test used in an exam of neurological function for balance. The exam is based on the premise that a person requires at least two of the three following senses to maintain balance while standing: * proprioception (the ability to know one's body position in space) * vestibular function (the ability to know one's head position in space) * vision (which can be used to monitor and adjust for changes in body position). A patient who has a problem with proprioception can still maintain balance by using vestibular function and vision. In the Romberg test, the standing patient is asked to close their eyes. An increased loss of balance is interpreted as a positive Romberg's test. The Romberg test is a test of the body's sense of positioning (proprioception), which requires healthy functioning of the dorsal columns of the spinal cord. The Romberg test is used to investigate the cause of loss of motor coordination (ataxia). A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflexes
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a Stimulus (physiology), stimulus. Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs via neural pathways in the nervous system called reflex arcs. A stimulus initiates a neural signal, which is carried to a synapse. The signal is then transferred across the synapse to a motor neuron, which evokes a target response. These neural signals do not always travel to the brain, so many reflexes are an automatic response to a stimulus that does not receive or need conscious thought. Many reflexes are fine-tuned to increase organism survival and self-defense. This is observed in reflexes such as the Startle response, startle reflex, which provides an automatic response to an unexpected stimulus, and the Cat righting reflex, feline righting reflex, which reorients a cat's body when falling to ensure safe landin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysarthria
Dysarthria is a speech sound disorder resulting from neurological injury of the motor component of the motor–speech system and is characterized by poor articulation of phonemes. It is a condition in which problems effectively occur with the muscles that help produce speech, often making it very difficult to pronounce words. It is unrelated to problems with understanding language (that is, dysphasia or aphasia), although a person can have both. Any of the speech subsystems ( respiration, phonation, resonance, prosody, and articulation) can be affected, leading to impairments in intelligibility, audibility, naturalness, and efficiency of vocal communication. Dysarthria that has progressed to a total loss of speech is referred to as anarthria. The term ''dysarthria'' was formed from the Greek components ''dys-'' "dysfunctional, impaired" and ''arthr-'' "joint, vocal articulation". Neurological injury due to damage in the central or peripheral nervous system may result in wea ... [...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] |
Pseudoathetosis
Pseudoathetosis is abnormal writhing movements, usually of the fingers, caused by a failure of joint position sense (proprioception) and indicates disruption of the proprioceptive pathway, from nerve to parietal cortex. Presentation Analogous to Romberg's sign, the abnormal posturing is most pronounced when the eyes are closed as visual inputs are unavailable to guide corrective movements. Paradoxically, eye closure may decrease the amount of movement as the visual cues probably trigger corrective movements which return the limb to the desired "baseline" allowing a new phase of involuntary drift before a subsequent corrective phase occurs. Variants Hemipseudaoathetosis refers to pseudoathetosis on one side of the body, usually the upper limb and is most commonly caused by a lesion affecting the cuneate tract or cuneate nucleus in the cervical spine or lower brainstem (medulla) respectively. Diagnosis Differential diagnosis It may be mistaken for choreoathetosis; but these abnormal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuropathy
Peripheral neuropathy, often shortened to neuropathy, refers to damage or disease affecting the nerves. Damage to nerves may impair sensation, movement, gland function, and/or organ function depending on which nerve fibers are affected. Neuropathies affecting motor, sensory, or autonomic nerve fibers result in different symptoms. More than one type of fiber may be affected simultaneously. Peripheral neuropathy may be acute (with sudden onset, rapid progress) or chronic (symptoms begin subtly and progress slowly), and may be reversible or permanent. Common causes include systemic diseases (such as diabetes or leprosy), hyperglycemia-induced glycation, vitamin deficiency, medication (e.g., chemotherapy, or commonly prescribed antibiotics including metronidazole and the fluoroquinolone class of antibiotics (such as ciprofloxacin, levofloxacin, moxifloxacin)), traumatic injury, ischemia, radiation therapy, excessive alcohol consumption, immune system disease, celiac dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Columns
The dorsal column nuclei are a pair of nuclei in the dorsal columns of the dorsal column–medial lemniscus pathway (DCML) in the brainstem. The name refers collectively to the cuneate nucleus and gracile nucleus, which are situated at the lower end of the medulla oblongata. Both nuclei contain second-order neurons of the DCML, which convey fine touch and proprioceptive information from the body to the brain via the thalamus. Structure Nerve pathways The dorsal column nuclei each have an associated nerve tract in the spinal cord, the gracile fasciculus and the cuneate fasciculus, together forming the dorsal columns. Both dorsal column nuclei contain synapses from afferent nerve fibers that have travelled in the spinal cord. They then send on second-order neurons of the dorsal column–medial lemniscal pathway. Neurons of the dorsal column nuclei eventually reach the midbrain and the thalamus. They send axons that form the internal arcuate fibers. These cross over at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
