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A lower motor neuron lesion is a lesion which affects nerve fibers traveling from the ventral horn or anterior grey column of the spinal cord to the relevant muscle(s) – the lower motor neuron. One major characteristic used to identify a lower motor neuron lesion is flaccid paralysis – paralysis accompanied by loss of muscle tone. This is in contrast to an upper motor neuron lesion, which often presents with spastic paralysis – paralysis accompanied by severe hypertonia. == Symptoms == * Muscle paresis or paralysis * fibrillations * fasciculations- caused by increased receptor concentration on muscles to compensate for lack of innervation. * hypotonia or atonia- Tone is not velocity dependent. * Hyporeflexia -Along with deep reflexes even cutaneous reflexes are also decreased or absent * Strength -weakness is limited to segmental or focal pattern, Root innervated pattern The extensor Babinski reflex is usually absent. Muscle paresis/paralysis, hypotonia/atonia, and hyporeflexia/areflexia are usually seen immediately following an insult. Muscle wasting, fasciculations and fibrillations are typically signs of end-stage muscle denervation and are seen over a longer time period. Another feature is the segmentation of symptoms - only muscles innervated by the damaged nerves will be symptomatic. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「lower motor neuron lesion」の詳細全文を読む スポンサード リンク
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