acuity怎么理解？

The clinical presentation of a herniated nucleus pulposus varies from no symptoms to rapid paralysis. Symptom severity often correlates with the acuity and degree of com- pression to the neural and vascular elements. In the lumbar spine, herniations are most common at L4–L5 and L5–S1. Manifestation of herniated discs ranges from progressive motor weakness along the affected nerve root(s) up to the bladder and bowel to sexual dysfunction from conditions such as conus medullaris and cauda equina syndrome.Fortunately, extreme presentations are rare, with incidence of about 1–2% in lumbar disc herniations and about 4 in 10,000 in all low back pain patients, but should connote immediate further evaluation [31]. Common presenting features of simple disc herniation include radicular pain and numbness, dysesthesias, motor weakness, and even muscle atrophy from prolonged compression or disuse. The lumbar spine is the most common location for symptomatic disc herniations accounting for 80% of all disc herniations. Common symptoms of symptomatic lumbar disc herniations are varied and include lower back and buttock pain, with or without radicular leg pain and sensory dysesthesias. These symptoms may be partially relieved with rest, activity modification, or change in position. Trunk flexion, prolonged standing or sitting, and straining maneuvers (i.e., Valsalva, cough) commonly increase the symptoms of disc herniation.

椎间盘髓核突出症的临床表现从无症状到迅速瘫痪不等。症状的严重程度往往与神经和血管因素受压的程度和敏感性相关。在腰椎中，L4～L5和L5～S1突出最常见。椎间盘突出症的表现包括沿受累神经根进行性运动无力，以及脊髓圆锥和马尾综合征等引起的膀胱、肠道和性功能障碍。但是严重症状很少见，1～2%的腰椎间盘突出症患者和4 / 10000的腰痛患者会表现严重症状，一旦出现应立即进行进一步评估^[31]。单纯椎间盘突出症的常见表现包括神经根性疼痛和麻木、感觉异常、运动无力，甚至因长期压迫或废用而导致肌肉萎缩。腰椎间盘突出症是最常见且占所有椎间盘突出症的80%。症状性腰椎间盘突出症的常见症状多种多样，包括腰部和臀部疼痛，伴有或不伴有神经根性下肢痛和感觉异常。这些症状可通过休息、活动调整或体位改变后部分缓解。躯干屈曲，长时间站立或坐着，以及用力的动作(如瓦氏动作、咳嗽)通常会增加椎间盘突出症的症状。

acuity怎么理解？敏感性？