Savage Sharon A, Butler Christopher R, Milton Fraser, Han Yang, Zeman Adam Z
Cognitive & Behavioural Neurology, University of Exeter Medical School, College House, St Luke's Campus, Exeter EX1 2LU, UK.
Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, John Radcliffe Hospital, OX3 9DU, UK.
Epilepsy Behav. 2017 Jan;66:113-119. doi: 10.1016/j.yebeh.2016.09.043. Epub 2016 Dec 28.
While olfactory hallucinations are relatively rare in epilepsy, a high prevalence (up to 42%) has been reported in one form - Transient Epileptic Amnesia (TEA). TEA is characterized by recurring amnestic seizures and is commonly associated with persistent interictal memory deficits. Despite reports of changes in smell, olfactory ability has not been objectively assessed in this group. The aim of this study was to measure olfactory ability in patients with TEA and explore whether olfactory symptoms relate to other clinical variables.
Fifty-five participants with TEA were recruited from The Impairment of Memory in Epilepsy project database. The presence of olfactory symptoms was obtained via case notes and clinical interview. Participants completed questionnaires to evaluate their olfaction and memory function subjectively. Olfactory ability was measured using the University of Pennsylvania Smell Identification Test (UPSIT). TEA participants' performance was compared to 50 matched healthy control participants. A subset of TEA participants (n=26) also completed a battery of memory tests including standard neuropsychological measures, and assessment of accelerated long-term forgetting and autobiographical memory.
Olfactory hallucinations were reported in 55% of patients with TEA. A significant reduction in smell identification (UPSIT) was found between patients with TEA and healthy controls (p<0.001). Epilepsy variables, including history of olfactory hallucinations, were not predictive of olfactory ability. Patients reported ongoing memory difficulties and performed below normative values on objective tests. While no correlation was found between objective measures of memory and olfactory performance, subjective complaints of route finding difficulty was associated with UPSIT score.
Impairments in odor identification are common in patients with TEA and exceed changes that occur in normal aging. Olfactory hallucinations occurs in approximately half of patients with TEA, but do not always coincide with reduced sense of smell. Olfactory impairment and interictal memory problems both occur frequently in TEA but are not closely associated.
虽然嗅觉幻觉在癫痫中相对少见，但在一种形式——短暂性癫痫性遗忘症（TEA）中报告的患病率较高（高达42%）。TEA的特征是反复出现遗忘性发作，通常与持续性发作间期记忆缺陷相关。尽管有嗅觉变化的报告，但该组患者的嗅觉能力尚未得到客观评估。本研究的目的是测量TEA患者的嗅觉能力，并探讨嗅觉症状是否与其他临床变量相关。
从癫痫记忆损害项目数据库中招募了55名TEA患者。通过病例记录和临床访谈了解嗅觉症状的存在情况。参与者完成问卷以主观评估他们的嗅觉和记忆功能。使用宾夕法尼亚大学嗅觉识别测试（UPSIT）测量嗅觉能力。将TEA参与者的表现与50名匹配的健康对照参与者进行比较。一部分TEA参与者（n = 26）还完成了一系列记忆测试，包括标准神经心理学测量以及加速长期遗忘和自传体记忆的评估。
55%的TEA患者报告有嗅觉幻觉。TEA患者与健康对照之间的嗅觉识别（UPSIT）有显著降低（p < 0.001）。癫痫变量，包括嗅觉幻觉史，不能预测嗅觉能力。患者报告持续存在记忆困难，并且在客观测试中的表现低于正常标准值。虽然在记忆的客观测量与嗅觉表现之间未发现相关性，但主观上对寻路困难的抱怨与UPSIT得分相关。
气味识别障碍在TEA患者中很常见，且超过正常衰老过程中发生的变化。约一半的TEA患者会出现嗅觉幻觉，但并不总是与嗅觉减退同时出现。嗅觉损害和发作间期记忆问题在TEA中都很常见，但没有密切关联。
