Willis Gregory L, Turner E John D
The Bronowski Institute of Behavioural Neuroscience, Coliban Medical Centre, Kyneton, Victoria, Australia.
Chronobiol Int. 2007;24(3):521-37. doi: 10.1080/07420520701420717.
The antagonism of melatonin in models of Parkinson's disease (PD) can reduce the severity of motor impairment associated with dopamine (DA) degeneration. In consideration of the potent antidepressant effects of bright light therapy (LT), that LT suppresses melatonin secretion, that depression is commonly observed in PD, and that exposure to constant light facilitates recovery from experimental PD, the object of the present study was to strategically administer LT to PD patients and observe the effects on depression, insomnia, and motor performance. Twelve patients diagnosed with PD were exposed to white fluorescent light for 1-1.5 h at an intensity of 1000 to 1500 lux once daily commencing 1 h prior to the usual time of sleep onset, approximately 22:00 h in most patients. All patients were assessed before LT commenced and at two weeks, five weeks, and regular intervals thereafter. Within two weeks after commencing LT, marked improvement in bradykinaesia and rigidity was observed in most patients. Tremor was not affected by LT treatment; however, agitation, dyskinaesia, and psychiatric side effects were reduced, as verified by decreased requirement for DA replacement therapy. Elevated mood, improved sleep, decreased seborrhea, reduced impotence, and increased appetite were observed after LT. LT permitted the reduction of the dose of L-dopa, bromocriptine, or deprenyl in some patients by up to 50% without loss of symptom control. Factors limiting the efficacy of LT included multiple disease states, treatment compliance, polypharmacy, emotional stress, advanced age, and predominance of positive symptoms. The results of this case series study confirms previous work describing light as efficacious in the treatment of PD and suggest that controlled trials may help to elucidate how LT might be used strategically as an adjunct therapy to improve the morbidity of PD patients.
褪黑素对帕金森病（PD）模型的拮抗作用可减轻与多巴胺（DA）变性相关的运动障碍严重程度。鉴于强光疗法（LT）具有强大的抗抑郁作用，LT可抑制褪黑素分泌，PD患者中常见抑郁症，且持续光照可促进实验性PD的恢复，本研究的目的是对PD患者进行战略性的LT治疗，并观察其对抑郁、失眠和运动表现的影响。12名被诊断为PD的患者，从通常入睡时间前1小时（大多数患者约为22:00）开始，每天一次暴露于强度为1000至1500勒克斯的白色荧光灯下1 - 1.5小时。在LT开始前以及之后的两周、五周和此后的定期时间对所有患者进行评估。开始LT治疗后两周内，大多数患者的运动迟缓及僵硬症状有明显改善。LT治疗对震颤无影响；然而，如DA替代治疗需求减少所证实，激越、运动障碍及精神副作用有所减轻。LT治疗后观察到情绪改善、睡眠好转、皮脂溢出减少、阳痿减轻及食欲增加。LT使部分患者的左旋多巴、溴隐亭或丙炔苯丙胺剂量减少达50%，且不影响症状控制。限制LT疗效的因素包括多种疾病状态、治疗依从性、联合用药、情绪应激、高龄以及阳性症状为主。该病例系列研究结果证实了之前关于光在PD治疗中有效的研究工作，并表明对照试验可能有助于阐明如何战略性地使用LT作为辅助治疗来改善PD患者的发病率。
