Latronico N, Alongi S, Guarneri B, Cappa S, Candiani A
II Servizio di Anestesia e Rianimazione, Università degli Studi, Brescia.
Minerva Anestesiol. 2000 Apr;66(4):225-31.
Coma is the condition in which both components of consciousness, wakefulness and awareness, are lost. Therefore, the comatose patient neither opens the eyes, nor utters comprehensible words or follows commands. In the vegetative state (VS), awareness (including all cognitive function and emotion) is lost, while the vegetative functions, including breathing and sleep-wake cycles (the wakefulness), persist. Usually VS follows a state of coma caused by traumatic or anoxic brain damage. Pathologic brain examination demonstrates extensive subcortical, white matter, bilateral thalamic, and brainstem lesions in various combinations. Bilateral cerebral cortical lesions are rare, and therefore cortex can be "out of action" despite unaltered structure. More rarely, VS is caused by brain developmental malformations in children, or metabolic or degenerative diseases in children and adults. These are the only cases in which patients are not comatose before VS becomes apparent. After 6-8 weeks of coma, patients regain the eye opening. In such a condition, the term coma is no longer appropriate. If awareness is absent, the patient can be defined as in VS. Finally, the VS is defined as persistent (PVS) when it has continued for at least 1 month. The diagnosis of VS and PVS are clinical and require assessment over an adequate period of time and the skills of a multidisciplinary experienced team. Diagnosis is very complex in infants younger than 3 months, and is not applicable to preterm neonates, with the unique exception of infants with anencephaly. Among ancillary diagnostic tools, dynamic PET studies show promise.
昏迷是指意识的两个组成部分，即觉醒和意识均丧失的状态。因此，昏迷患者既不会睁眼，也不会说出可理解的话语或听从指令。在植物状态（VS）下，意识（包括所有认知功能和情感）丧失，而包括呼吸和睡眠-觉醒周期（觉醒）在内的植物功能仍然存在。通常，植物状态继发于由创伤性或缺氧性脑损伤引起的昏迷状态之后。病理脑检查显示，存在广泛的皮质下、白质、双侧丘脑和脑干病变，病变组合多样。双侧大脑皮质病变较为罕见，因此尽管结构未改变，皮质仍可能“不起作用”。更罕见的是，植物状态由儿童脑发育畸形或儿童及成人的代谢性或退行性疾病引起。只有在这些情况下，患者在植物状态变得明显之前才不会处于昏迷状态。昏迷6 - 8周后，患者恢复睁眼。在这种情况下，昏迷这个术语就不再适用了。如果意识缺失，患者可被定义为处于植物状态。最后，当植物状态持续至少1个月时，被定义为持续性植物状态（PVS）。植物状态和持续性植物状态的诊断是临床诊断，需要在足够长的时间内进行评估，并需要多学科经验丰富的团队具备相关技能。对于小于3个月的婴儿，诊断非常复杂，并且不适用于早产儿，无脑儿婴儿是唯一的例外情况。在辅助诊断工具中，动态PET研究显示出前景。
