Department of Neurology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA.
Neurocrit Care. 2020 Jun;32(3):697-706. doi: 10.1007/s12028-020-00944-0.
BACKGROUND/OBJECTIVES: Clinical seizures following acute ischemic stroke (AIS) appear to contribute to worse neurologic outcomes. However, the effect of electrographic epileptiform abnormalities (EAs) more broadly is less clear. Here, we evaluate the impact of EAs, including electrographic seizures and periodic and rhythmic patterns, on outcomes in patients with AIS.
This is a retrospective study of all patients with AIS aged ≥ 18 years who underwent at least 18 h of continuous electroencephalogram (EEG) monitoring at a single center between 2012 and 2017. EAs were classified according to American Clinical Neurophysiology Society (ACNS) nomenclature and included seizures and periodic and rhythmic patterns. EA burden for each 24-h epoch was defined using the following cutoffs: EA presence, maximum daily burden < 10% versus > 10%, maximum daily burden < 50% versus > 50%, and maximum daily burden using categories from ACNS nomenclature ("rare" < 1%; "occasional" 1-9%; "frequent" 10-49%; "abundant" 50-89%; "continuous" > 90%). Maximum EA frequency for each epoch was dichotomized into ≥ 1.5 Hz versus < 1.5 Hz. Poor neurologic outcome was defined as a modified Rankin Scale score of 4-6 (vs. 0-3 as good outcome) at hospital discharge.
One hundred and forty-three patients met study inclusion criteria. Sixty-seven patients (46.9%) had EAs. One hundred and twenty-four patients (86.7%) had poor outcome. On univariate analysis, the presence of EAs (OR 3.87 [1.27-11.71], p = 0.024) and maximum daily burden > 10% (OR 12.34 [2.34-210], p = 0.001) and > 50% (OR 8.26 [1.34-122], p = 0.035) were associated with worse outcomes. On multivariate analysis, after adjusting for clinical covariates (age, gender, NIHSS, APACHE II, stroke location, stroke treatment, hemorrhagic transformation, Charlson comorbidity index, history of epilepsy), EA presence (OR 5.78 [1.36-24.56], p = 0.017), maximum daily burden > 10% (OR 23.69 [2.43-230.7], p = 0.006), and maximum daily burden > 50% (OR 9.34 [1.01-86.72], p = 0.049) were associated with worse outcomes. After adjusting for covariates, we also found a dose-dependent association between increasing EA burden and increasing probability of poor outcomes (OR 1.89 [1.18-3.03] p = 0.009). We did not find an independent association between EA frequency and outcomes (OR: 4.43 [.98-20.03] p = 0.053). However, the combined effect of increasing EA burden and frequency ≥ 1.5 Hz (EA burden * frequency) was significantly associated with worse outcomes (OR 1.64 [1.03-2.63] p = 0.039).
Electrographic seizures and periodic and rhythmic patterns in patients with AIS are associated with worse outcomes in a dose-dependent manner. Future studies are needed to assess whether treatment of this EEG activity can improve outcomes.
背景/目的：急性缺血性脑卒中（AIS）后出现的临床癫痫发作似乎与更差的神经功能结局相关。然而，更广泛的电描记图癫痫样异常（EAs）的影响尚不明确。在此，我们评估了 EAs（包括电发作和周期性及节律性模式）对 AIS 患者结局的影响。
这是一项对 2012 年至 2017 年期间在单一中心接受至少 18 小时连续脑电图（EEG）监测的年龄≥18 岁的所有 AIS 患者的回顾性研究。EAs 按照美国临床神经生理学会（ACNS）命名法进行分类，包括发作和周期性及节律性模式。每个 24 小时时段的 EA 负担使用以下截止值进行定义：EA 存在、最大日负担<10%与>10%、最大日负担<50%与>50%以及使用 ACNS 命名法的类别中的最大日负担（“罕见”<1%；“偶尔”1-9%；“频繁”10-49%；“丰富”50-89%；“连续”>90%）。每个时段的最大 EA 频率分为≥1.5 Hz 与<1.5 Hz。出院时改良 Rankin 量表评分 4-6（良好结局为 0-3）定义为不良神经结局。
143 名患者符合研究纳入标准。67 名患者（46.9%）存在 EAs。124 名患者（86.7%）结局不良。单因素分析显示，EAs 的存在（比值比 [OR] 3.87 [1.27-11.71]，p=0.024）和最大日负担>10%（OR 12.34 [2.34-210]，p=0.001）和>50%（OR 8.26 [1.34-122]，p=0.035）与结局不良相关。多因素分析显示，在校正临床协变量（年龄、性别、NIHSS、APACHE II、卒中部位、卒中治疗、出血转化、Charlson 合并症指数、癫痫病史）后，EAs 的存在（OR 5.78 [1.36-24.56]，p=0.017）、最大日负担>10%（OR 23.69 [2.43-230.7]，p=0.006）和最大日负担>50%（OR 9.34 [1.01-86.72]，p=0.049）与结局不良相关。在校正协变量后，我们还发现随着 EA 负担的增加，不良结局的概率也呈剂量依赖性增加（OR 1.89 [1.18-3.03]，p=0.009）。我们没有发现 EA 频率与结局之间存在独立的关联（OR：4.43 [.98-20.03]，p=0.053）。然而，增加的 EA 负担和频率≥1.5 Hz 的联合效应（EA 负担*频率）与结局不良显著相关（OR 1.64 [1.03-2.63]，p=0.039）。
AIS 患者的电发作和周期性及节律性模式与更差的神经功能结局呈剂量依赖性相关。需要进一步的研究来评估是否可以通过治疗这种 EEG 活动来改善结局。
