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Table of Contents    
Year : 2018  |  Volume : 66  |  Issue : 5  |  Page : 1501-1502

Balloon-assisted coil embolization of intracranial aneurysm and zero bispectral index

Department of Neuroanaesthesiology and Critical Care, All India Institute of Medical Sciences, New Delhi, India

Date of Web Publication17-Sep-2018

Correspondence Address:
Dr. Girija P Rath
Department of Neuroanaesthesiology and Critical Care, Neurosciences Centre, All India Institute of Medical Sciences, New Delhi
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0028-3886.241341

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How to cite this article:
Banik S, Rath GP, Ramsal R, Singh GP. Balloon-assisted coil embolization of intracranial aneurysm and zero bispectral index. Neurol India 2018;66:1501-2

How to cite this URL:
Banik S, Rath GP, Ramsal R, Singh GP. Balloon-assisted coil embolization of intracranial aneurysm and zero bispectral index. Neurol India [serial online] 2018 [cited 2019 Dec 15];66:1501-2. Available from:


The bispectral index (BIS) monitor has increasingly been utilized for the assessment of depth of anesthesia during interventional neuroradiological procedures. A 74-year old female, hypertensive patient was admitted to our center with the complaints of severe headache since the last 2 days. A non-contrast computed tomographic (CT) scan of the brain showed subarachnoid hemorrhage. As the patient was not cooperative, cerebral angiography under anesthesia was planned. The preanesthetic checkup revealed normal systemic and blood investigations, electrocardiogram, and chest X-ray. In the neuroradiology suite, anesthesia was induced with fentanyl 2μg/kg and propofol 2mg/kg, and tracheal intubation was facilitated with rocuronium 0.8mg/kg. The right femoral intra-arterial digital subtraction angiography (DSA) revealed an aneurysm of the anterior communicating artery. The balloon-assisted endovascular coiling was carried out during which a fall in BIS value to 0 was noted [Figure 1]; it was followed by hypertension. During this episode, the signal quality index (SQI) was 95%, electromyogram (EMG) remained below 30dB, and burst suppression ratio (BSR) increased to 100. The neuroradiologist was alerted about the possibility of aneurysmal rupture, which was confirmed by deflation of the balloon, that showed leakage of the contrast material [Figure 2]. A recovery of BIS value to more than 40 occurred in 8 min and the procedure was continued with protamine reversal. However, 30 min later, another episode of fall in BIS (to 0) occurred, which was accompanied by hypertension (208/116 mmHg) and bradycardia (46 bpm). The intra-arterial balloon was inflated to cover the site of rupture by creating a tamponade effect. Simultaneously, a small bolus of propofol and labetalol was injected to control the hypertensive responses. The procedure was abandoned and the patient was shifted to the neurosurgical intensive care unit with placement of an extraventricular drainage (EVD) for further management. She was pronounced dead 48 h later.
Figure 1: The table depicting the trend shown on the monitor of the fall of bispectral index (BIS) value to zero

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Figure 2: Digital subtraction angiography showing leakage of contrast from the site of rupture (arrow)

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A sudden drop in BIS value has been reported during coil embolization,[1] embolization of arteriovenous malformations,[2] and with the occurrence of intraventricular hemorrhage during a third ventriculostomy.[3] The rise in intracranial pressure and vasospasm are explained as possible causes for a decrease in BIS values.[4] However, this is the first case where reduced BIS value coincided with balloon-assisted endovascular coiling of an aneurysm. Also, the low BIS value was preceded by a rupture of the aneurysm, thereby facilitating its early management; the change in BIS value, therefore, may be indicative of cerebral ischemia.[5] The BIS monitoring can rapidly detect the intracranial aneurysmal rupture, especially during balloon-assisted coiling, as the contrast injection for detection of the rupture is not possible without deflation and withdrawal of the tamponade effect. This effect foreshadows the hemodynamic consequences of aneurysmal rupture. The report suggests that the use of BIS helps in detection of cerebral ischemia after an intraoperative cardiac arrest.[5] The electroencephalogram monitoring from the BIS montage may be of additional advantage during coil embolization; it may help in detection of the isoelectric trace and the burst suppression pattern during the administration of neuroprotection. The persistence of zero BIS, after the second rupture, as seen in our case, may have a prognostication value in determining a poor outcome. Nevertheless, the utility of BIS monitoring in detecting an intraoperative aneurysmal rupture needs further evaluation by utilizing large randomized controlled trials (RCTs).

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initial will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Prabhakar H, Ali Z, Rath GP, Singh D. Zero bispectral index during coil embolization of an intracranial aneurysm. Anesth Analg 2007;105:887-8.  Back to cited text no. 1
Unnikrishnan KP, Sinha PK, Sriganesh K, Suneel PR. Case report: Alterations in bispectral index following absolute alcohol embolization in a patient with intracranial arteriovenous malformation. Can J Anaesth 2007;54:908-11.  Back to cited text no. 2
Eapen G, Andrzejowski J. Sudden decrease of bispectral index during endoscopic neurosurgery: A case report. J Neurosurg Anesthesiol 2009;21:278.  Back to cited text no. 3
Smith M, Wiles M, Andrzejowski J, Eapen G. Interhemispheric EEG variability measured using a bilateral bispectral Index (BIS) sensor. J Neurosurg Anesthesiol 2012;24:244.  Back to cited text no. 4
Goodman PG, Mehta AR, Castresana MR. Predicting ischemic brain injury after intraoperative cardiac arrest during cardiac surgery using the BIS monitor. J Clin Anesth 2009;21:609-12.  Back to cited text no. 5


  [Figure 1], [Figure 2]


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