不寧腿症候群(RLS)這現象早在17世紀英國醫生即有描述過此症狀，到20世紀Ekbom 醫生詳細的描述此病徵，並命名為不寧腿症候群(Willis-Ekbom 病)。根據美國睡眠醫學會的分類標準，不寧腿的診斷主要是靠臨床的主觀感覺症狀，包括有下列主要特徵：(1)肢體有異常感覺，如爬行、搔癢蟲爬等異常感覺。(2)肢體在靜止休息時使症狀惡化，肢體的運動會緩解此異常感覺。(3)在夜間會惡化，影響睡眠造成難以入眠而白天則有嗜睡現象。(4)靜止不動也會惡化，睡覺中有肢體動作異常，影響睡眠。一般可用問卷，根據病人的答案即可正確診斷此症候群，與一般動作異常的疾病相似。在臨床上三種類似的病症RLS、PLMS 及PLMD 常需作鑑別診斷。RLS 主要是靠症狀的描述，根據病史詢問在門診即可診斷，而PLMS 則必須是靠實驗室的夜間睡眠檢查(PSG)，有客觀PSG 的記錄為憑。而PLMD 則必須靠病史詢問加上PSG，此類疾病的致病機轉仍不是很清楚。本文的重點是簡介RLS 及週期性肢動異常(PLMD)的最新進展。

Two sleep disorders are interested by neurologists, one is parasomnias and the other includes restless leg syndrome (RLS) and periodic limb movement disorder (PLMD), parasomnias are defined as undesirable physical behavior that occurs during sleep. RLS was first described in the medical literature in 17th century. The development of sleep medicine renews the interest in this disorder. In 2002, a new diagnostic criteria was set by NIH experts. The diagnosis of RLS is based on clinical history. There are 4 elements for diagnosis: (1) urge to move; (2) rest makes worse; (3) gets better with movement; (4) worse in the evening. 5 classes of medication showed effective for the treatment of RLS: dopaminergic agonist or precursor, opioids, anticonvulsants, iron supplement, benzodiazepines. PLMD is defined for PSG recordings reported by Symonds as nocturnal myoclonus in 1953. PLMD is strongly influenced by the sleep-wake state, both cortical arousal and autonomic arousal during sleep produce clinically significant aversive consequences.