Binkley K E, Kutcher S
Saint Michael's Hospital, Department of Medicine, University of Toronto, Ontario, Canada.
J Allergy Clin Immunol. 1997 Apr;99(4):570-4. doi: 10.1016/s0091-6749(97)70086-1.
Many patients who are first seen with what has been called multiple chemical sensitivity syndrome (MCS) experience symptoms suggestive of panic disorder including chest tightness, shortness of breath, palpitations, paresthesias, light-headedness, and mental confusion. Although such patients are often convinced that these symptoms reflect toxic effects of environmental "chemicals," direct evidence of this is lacking. To the contrary, a previous study has shown that some of these individuals exhibit hyperventilation responses on exposure to non-noxious stimuli, and it has been suggested that the resulting hypocarbia accounts for their symptoms. We postulated that some patients with self-identified MCS had an underlying condition similar to panic disorder and would therefore demonstrate similar responses to provocative challenges, such as sodium lactate infusion.
Patients referred to an allergy and clinical immunology service for evaluation of "chemical sensitivity" were investigated to rule out underlying medical conditions, including asthma, as a cause of their symptoms and were enrolled for study after giving informed consent. After a standardized psychiatric assessment was performed, patients underwent single-blind intravenous infusions of normal saline solution (placebo) and sodium lactate (which reproduces symptoms in individuals with underlying panic disorder). All patients were referred for independent psychiatric assessment.
The standardized psychiatric assessment identified four of five patients as meeting DSM III-R diagnostic criteria for panic disorder along with other depressive and/or anxiety-related disorders. All five patients with self-identified chemical sensitivity exhibited a positive symptomatic response to sodium lactate compared with placebo infusion. Independent psychiatric assessment confirmed the diagnosis of panic disorder on the basis of DSM III-R criteria in each of the five patients.
These results suggest that MCS may have a neurobiologic basis similar, if not identical, to that of panic disorder. We speculate that treatments with demonstrated efficacy in panic disorder may also be of benefit in MCS, and conversely, treatments that reinforce anticipatory anxiety and avoidance behavior in patients with MCS may be detrimental.
许多初诊为所谓多重化学物质敏感综合征（MCS）的患者出现提示惊恐障碍的症状，包括胸闷、呼吸急促、心悸、感觉异常、头晕和精神错乱。尽管这些患者常常坚信这些症状反映了环境“化学物质”的毒性作用，但缺乏直接证据。相反，先前的一项研究表明，其中一些个体在接触无害刺激时会出现过度通气反应，有人提出由此产生的低碳酸血症是其症状的原因。我们推测，一些自我认定为MCS的患者存在与惊恐障碍相似的潜在病症，因此对激发性挑战（如输注乳酸钠）会表现出类似反应。
转诊至过敏与临床免疫科评估“化学物质敏感性”的患者接受检查，以排除包括哮喘在内的潜在疾病作为其症状的病因，在获得知情同意后纳入研究。进行标准化精神科评估后，患者接受生理盐水溶液（安慰剂）和乳酸钠（在有潜在惊恐障碍的个体中可重现症状）的单盲静脉输注。所有患者均被转诊接受独立的精神科评估。
标准化精神科评估确定五名患者中有四名符合DSM III-R惊恐障碍诊断标准以及其他抑郁和/或焦虑相关障碍。与输注安慰剂相比，所有五名自我认定为化学物质敏感的患者对乳酸钠均表现出阳性症状反应。独立精神科评估根据DSM III-R标准确认了这五名患者中每例的惊恐障碍诊断。
这些结果表明，MCS可能具有与惊恐障碍相似（如果不是相同）的神经生物学基础。我们推测，在惊恐障碍中已证明有效的治疗方法可能对MCS也有益，相反，强化MCS患者预期焦虑和回避行为的治疗可能有害。
