Measuring the Optic Nerve Sheath Diameter with Ultrasound in Acute Middle Cerebral Artery Stroke Patients Seda G€ uzelda g, MD,* G€ okhan Yılmaz, MD,† Merva Tuna,‡ M€ ukerrem Altunta ¸ s,† and Mustafa € Ozdemir,§ Background: Measurement of the optic nerve sheath diameter (ONSD) with ultrasound enables non-invasive and indirect assessment of increased intracranial pressure (ICP). Although most of the studies were employed with traumatic brain injury patients, it's increasingly popular in acute ischemic stroke (AIS) studies. Objectives: Evaluating whether using ONSD as a follow-up measurement would help monitor the thrombo- lytic therapy (TT) effectiveness and determine the high-risk patients for malignant mid- dle cerebral artery (MCA) syndrome. Methods: This prospective observational study was conducted between August 1, 2019, and February 1, 2020, in a tertiary hospital. Forty-four patients were eligible. We determined the TT moment as the time when the first ocular ultrasound measurement would be made (time 0). Also, we decided on the 24 th h after the treatment as the time to perform the second ocular ultrasound measure- ment (time 24). The National Institute of Health Stroke Scale (NIHSS), the Glasgow Coma Scale (GCS), and the Alberta Stroke Program Early Computed Tomography (ASPECT) scores were evaluated blindly at the time-0 and the time-24. The cut-off value of ONSD was 0.55 mm. Results: There was no difference in ONSD results before and after the TT (p = 0.414). But, patients with an equal or higher value than cut-off had an increased risk for complications such as malignant-MCA, bleeding, seizure, etc. (p = 0.05). Malignant-MCA was observed in four patients with higher ONSD values. At the time-24, NIHSS decreased, GCS and ASPECT scores increased. Finally, ONSD was positively correlated with the NIHSS and negatively correlated with the GCS at the time-24. Conclusions: Monitoring ONSD values in both the emergency department and the intensive care unit may be useful in the early diagnosis of MCA stroke compli- cations and the follow-up of TT’s effectiveness. Key Words: Optic Nerve Sheath Diameter—Thrombolytic Therapy—Middle Cerebral Artery Infarction—Stroke © 2020 Elsevier Inc. All rights reserved. Introduction Acute stroke is a localized loss of brain function that can suddenly deteriorate. 1 It's common worldwide and causes millions of deaths. Ischemic strokes constitute the major- ity of acute strokes, and the incidence of death from ische- mic strokes varies between 10-20%. 1,2 The most common cause of Acute Ischemic Stroke (AIS) is the occlusion of the Middle Cerebral Artery (MCA) or its branches. 3 Acute MCA occlusion has a risk of malignant MCA, char- acterized by severe edema and increased mortality, generally in the first week. 3 The skull has a constant volume. Any increase in volume caused by bleeding, edema, etc. increases the pressure inside the skull. Consequently, secondary neu- ronal damage and even death may occur. 4 6 This increased intracranial pressure can be detected and followed by many invasive and non-invasive methods. 7 10 Abbreviations: ONSD, Optic Nerve Sheath Diameter; ICP, Intracra- nial Pressure; AIS, Acute Ischemic Stroke; MCA, Acute Middle Cere- bral Artery; TT, Thrombolytic Therapy; NIHSS, National Institute of Health Stroke Scale; GCS, Glasgow Coma Scale; ASPECT, Alberta Stroke Program Early Computed Tomography; APACHE-II, Acute Physiology and Chronic Health Assessment-II From the *Department of Neurointensive Care, Kayseri City Hospi- tal, Kayseri, Turkey; †Department of Emergency Medicine, Kayseri City Hospital, Kayseri, Turkey; ‡Department of Neurology, Kayseri City Hospital, Kayseri, Turkey; and §Department of Radiology, Kay- seri City Hospital, Kayseri, Turkey. Received September 21, 2020; revision received November 21, 2020; accepted November 30, 2020. Address correspondence to Seda Guzeldag, MD, Kayseri City Hospital, Neurointensive Care Unit, Turkey. E-mail: guzeldagseda@gmail.com. 1052-3057/$ - see front matter © 2020 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jstrokecerebrovasdis.2020.105523 Journal of Stroke and Cerebrovascular Diseases, Vol. 30, No. 2 (February), 2021: 105523 1