Department of Clinical and Experimental Epilepsy, Institute of Neurology UCL, Queen Square, London, UK.
Med Hypotheses. 2011 May;76(5):661-4. doi: 10.1016/j.mehy.2011.01.025. Epub 2011 Feb 18.
From a neurobiological level to epidemiological studies, there are four strands of evidence in the scientific literature that indicate that light therapy could be an effective treatment for some people with epilepsy. (1) Sunlight is important in the endogenous production and regulation of melatonin and vitamin D, both of which influence seizure thresholds. Although melatonin influences seizure thresholds, the relationship is complex. General down-regulating effects may have different effects on seizure thresholds for people with generalised and partial epilepsy syndromes. Specific actions within the hippocampus may mean that patients with temporal lobe epilepsy are particularly susceptible to the endogenous expression of melatonin via inhibitory actions on dopaminergic activity reducing seizure thresholds. (2) If suppression of melatonin results in fewer seizures this should be evident in seasonal variations in seizure frequencies. Seizure frequencies increase in the winter and on dull overcast days. Within this larger circannual rhythm, local light conditions are also associated with variations in seizure frequencies. Controlling for seasonal patterns, complex partial seizures are significantly less likely to occur on bright sunny days, than on dull days with fewer hours of sunshine, regardless of the time of year. (3) On a wider scale, some epidemiological studies also suggest a lower prevalence of epilepsy in southern Europe compared to Scandinavia and Northern Europe. (4) Light therapy is an established medical treatment for depression. Recent research suggests that some forms of epilepsy and depression are bi-directional conditions. The mechanism of action underlying light therapy for affective disorders remains the subject of much research but is thought to involve the enhancement of the monoaminergic systems targeted by antidepressant drugs (serotonin, dopamine, and norepinephrine); systems also implicated in a number of epilepsy syndromes. In this paper, we propose the hypothesis that exposure to high intensity light may be an effective, non-invasive add-on treatment for people with temporal lobe epilepsy. Although it is more likely to be palliative than curative, it may help smooth out some of the seasonal peaks in seizure frequencies, a pattern that increases the risk of serious manifestations of the condition such as status epilepticus and sudden unexpected death in epilepsy.
从神经生物学层面到流行病学研究，科学文献中有四条证据表明光疗可能是一些癫痫患者的有效治疗方法。(1) 阳光对于内源性褪黑素和维生素 D 的产生和调节很重要，这两者都会影响癫痫发作的阈值。虽然褪黑素会影响癫痫发作的阈值，但这种关系很复杂。一般的下调作用可能对全身性和部分性癫痫综合征患者的癫痫发作阈值有不同的影响。海马体内的特定作用可能意味着颞叶癫痫患者特别容易受到内源性褪黑素表达的影响，因为它通过抑制多巴胺能活动来降低癫痫发作阈值。(2) 如果抑制褪黑素导致癫痫发作减少，那么这应该在癫痫发作频率的季节性变化中得到体现。癫痫发作在冬季和阴暗多云的日子里增加。在这个较大的年节律中，局部光照条件也与癫痫发作频率的变化有关。在控制季节性模式的情况下，与在阳光较少的阴暗日子相比，复杂部分性癫痫发作在阳光明媚的日子里发生的可能性显著降低，无论一年中的时间如何。(3) 在更大的范围内，一些流行病学研究也表明，与斯堪的纳维亚和北欧相比，南欧的癫痫患病率较低。(4) 光疗是一种已被确立的治疗抑郁症的方法。最近的研究表明，一些形式的癫痫和抑郁症是双向疾病。光疗对情感障碍的作用机制仍然是许多研究的主题，但据认为涉及到抗抑郁药物（血清素、多巴胺和去甲肾上腺素）靶向的单胺能系统的增强；这些系统也与许多癫痫综合征有关。在本文中，我们提出了一个假设，即高强度光照暴露可能是颞叶癫痫患者的一种有效、非侵入性的附加治疗方法。虽然它更可能是姑息性的而不是治愈性的，但它可能有助于缓解癫痫发作频率的一些季节性高峰，这种模式会增加癫痫持续状态和癫痫猝死等疾病严重表现的风险。
