Search results
Results from the WOW.Com Content Network
Such lesions give rise to extensive astrocyte loss, which may occur in part in the absence of any other tissue injury, such as demyelination or axonal degeneration (lesion type 5). Finally, lesions with a variable degree of astrocyte clasmatodendrosis are found, which show plaque-like primary demyelination that is associated with ...
Acute motor axonal neuropathy (AMAN) is a variant of Guillain–Barré syndrome. It is characterized by acute paralysis and loss of reflexes without sensory loss. Pathologically , there is motor axonal degeneration with antibody-mediated attacks of motor nerves and nodes of Ranvier .
Neurapraxia is a temporary interruption of conduction without loss of axonal continuity. [3] Neurapraxia involves a physiologic block of nerve conduction in the affected axons. Other characteristics: mildest type of nerve injury; sensory-motor problems present distal to the site of injury; intact endoneurium, perineurium, and the epineurium
N-cadherin agonists have been identified and observed to stimulate neurite growth and cell migration, key aspects of promoting axon growth and remyelination after injury or disease. [ 25 ] Immunomodulatory drugs such as fingolimod have been shown to reduce immune-mediated damage to the CNS, preventing further damage in patients with MS.
When a nerve axon is severed, the end still attached to the cell body is labeled the proximal segment, while the other end is called the distal segment. After injury, the proximal end swells and experiences some retrograde degeneration, but once the debris is cleared, it begins to sprout axons and the presence of growth cones can be detected.
These nerves are as long as 1-1.5 meters (sciatic nerve). Most of the substances the axon needs to survive is manufactured in the cell body. [2] The axon's survival depends on its connection with the cell body, supported by the axonal transport mechanisms to carry cellular material. [4]
Alcoholic polyneuropathy usually has a gradual onset over months or even years, although axonal degeneration often begins before an individual experiences any symptoms. [ 2 ] The disease typically involves sensory issues and motor loss, as well as painful physical perceptions, though all sensory modalities may be involved. [ 3 ]
The axon and encapsulating connective tissue lose their continuity. The last (extreme) degree of neurotmesis is transsection, but most neurotmetic injuries do not produce gross loss of continuity of the nerve but rather internal disruption of nerve structures sufficient to involve perineurium and endoneurium as well as axons and their covering ...