Lower Motor Neuron Paralysis
In lower motor neuron paralysis, pathological (abnormal) reflexes are also absent. The loss of reflexes occurs because the reflex arcs (paths followed by nerve impulses) are damaged forever. In lower motor neuron paralysis, nerve impulses travel abnormally and muscle twitching is present. If the spinal cord is totally cut, all voluntary muscle control is lost. If the spinal cord is partially cut, muscle function will vary, depending on which particular nerves are still entering which particular areas. Compare lower motor neuron paralysis with upper motor neuron paralysis, a type of disorder that causes loss of movement and sensation due to injury or damage to upper motor neurons.
Lower motor neuron paralysis is a type of paralysis (loss of movement and/or sensation) that is due to injury or damage in the brain or spinal cord. This injury or damage in the brain or spinal cord causes damage to the cell body (the main part of the cell) and/or axons (the part of a nerve that sends a message) of the lower motor neuron. A lower motor neuron is the part of a motor neuron (a type of nerve cell) sends messages via upper motor neurons to the skeletal muscles. Upper motor neurons are neurons (nerve cells) in the motor cortex (an area of the brain located in middle, top part of the brain) that form pathways within the brain and from the brain to the spine. Skeletal muscles are muscles that are connected at either or both arms or legs with the skelton of the body.
In lower motor neuron paralysis, wasting away of muscles occur. The muscle wasting is severe, with affected individuals losing 70 to 80% of their body bulk. Low muscle tone (tension) and weakness is present in affected muscles. Muscles with low tension usually appear flabby. There is also loss of deep tendon reflexes, which is when the muscle contracts (shortens) in response to a stretched muscle that caused by a sharp tap.
In lower motor neuron paralysis, wasting away of muscles occur. The muscle wasting is severe, with affected individuals losing 70 to 80% of their body bulk. Low muscle tone (tension) and weakness is present in affected muscles. Muscles with low tension usually appear flabby. There is also loss of deep tendon reflexes, which is when the muscle contracts (shortens) in response to a stretched muscle that caused by a sharp tap.
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