原发性侧索硬化(PLS)是一种以单纯皮层脊髓束和皮层延髓束受损害为特征的运动神经元综合征。磁共振影象(MRI)可发现锥体束选择性变性,但目前还未见有PLS表现为MRI异常的病例报道,本文作者报告1例。患者女,46岁。五年前先发现右手不灵活,起病一年后上述症状呈进行性加重,继而右下肢开始出现缓慢、强直和拖曳步态,几年内症状发展缓慢,左下肢亦受累,迈步日趋困难,并伴有构音障碍、吞咽困难和病理性哭笑。查体:患者面部表情呆滞,面部反射(尤其颌反射)亢进,构音障碍,全身痉挛强直状,四肢腱反射亢进,双下肢病理反射阳性;肌力正常,但动作慢而笨拙,痉挛样步态;无肌束 Primary lateral sclerosis (PLS) is a motor neuron syndrome characterized by impaired corticospinal tract and cortical medullary bundles. Magnetic resonance imaging (MRI) can be found selective degeneration of pyramidal tract, but no cases of PLS ​​showed MRI abnormalities, the authors report 1 case. Female patient, 46 years old. Five years ago found that the right hand is not flexible, one year after onset of the symptoms were progressive aggravating, and then the right lower limb began to appear slow, tonic and towing gait, a few years the symptoms developed slowly, the left lower extremity also involved, the progress of increasingly difficult and Accompanied by dysarthria, dysphagia and pathological muffled. Physical examination: patients with facial expressions dull, facial reflex (especially jaw reflex) hyperthyroidism, dysarthria, systemic spastic straight, extremity tendon hyperreflexia, both lower limb pathology reflex positive; muscle strength is normal, but slow and clumsy movements, spasmodic step State; no muscle bundle