ICU-cEEG Monitoring

ABSTRACT

The neurological application of long-term electroencephalography (EEG) monitoring in the intensive care unit (ICU) has been implemented in many healthcare institutions. The use of EEG as a monitoring tool in the ICU affords many potential benefits. Uses include the identification of seizures, vasospasm following subarachnoid hemorrhage (SAH), the assessment of coma and the determination of brain death. Neurologic critical care is focused on recognition and treatment of secondary insults. Often treatment is withheld because these insults are not recognized early enough until an irreversible deficit manifest. Continuous EEG (cEEG) monitoring provides a unique potential to recognize these insults and offers an opportunity for early intervention. Why should we continuously monitor the brain with EEG in the ICU? Nonconvulsive seizures (NCS) are common in comatose patients. Nonconvulsive Status Epilepticus (NCSE) and NCS¹ are damaging to brain tissue; thus, rapid control of seizures is essential to preserving brain function. With the increased use of cEEG in critical care areas, the purpose of this paper is to examine the use and benefits of EEG monitoring of ICU patients, review the indications for the use of cEEG and discuss technical issues and concerns when performing cEEG monitoring. This article has been divided into six distinct sections: (1) Seizures, NCS, and NCSE (2) Periodic Discharges² and Patterns on the Ictal-interictal Continuum, (3) Cerebral Ischemia, SAH, and Delayed Cerebral Ischemia (DCI), (4) Encephalopathy and Coma (5) ECI and Brain Death, and (6) ICU-cEEG Monitoring Techniques.

KEY WORDS:

• Delayed cerebral ischemia
• EEG ICU monitoring
• neuro-critical care
• nonconvulsive seizures
• vasospasm

Acknowledgments

I would like to thank my supportive wife, LuAnn Banoczi, for her helpful comments and assistance in the preparation of this manuscript. Without the application of her production skills, this article would not have been satisfactorily completed.

I am also very appreciative of the contributions that Moberg ICU Solutions and Persyst Development Corporation provided by allowing me to include their trend displays and case histories.

Disclosure Statement

No potential conflict of interest was reported by the author.

Notes

1. Proposed ACNS 2021 Guideline 14: Standardized Critical Care EEG Terminology: Electrographic Status Epilepticus (ESE) and Electrographic Seizures (ESz).

2. Proposed ACNS 2021 Guideline 14: Standardized Critical Care EEG Terminology: Rhythmic and Periodic Patterns (RPP).

3. Proposed ACNS 2021 Guideline 14: Standardized Critical Care EEG Terminology: Unilateral Independent Discharges (UIPDs).

4. Proposed ACNS 2021 Guideline 14: Standardized Critical Care EEG Terminology: Cyclic alternating pattern of encephalography (CAPE).

5. Proposed ACNS 2021 Guideline 14: Standardized Critical Care EEG Terminology: Highly Epileptiform Bursts, Identical Bursts, Anterior-posterior (AP) gradient and Breach effect.