Continuous Bedside EEG Monitoring Benefits Pediatric Patients

By Deepak Lachhwani, MD

When it comes to monitoring the brain health of Cleveland Clinic’s pediatric inpatients, the future has arrived. Cleveland Clinic Children’s is in a distinct position to offer continuous, 24/7 EEG (cEEG) monitoring services for children who need monitoring of brain function in the intensive care unit (ICU) or any other hospital bed. We are one of the only centers in the country providing continuous technologist review of EEG tracings backed with interpretation by physician specialists in EEG and epilepsy.

A recent survey in the United States and Canada found that very few institutions have clinical pathways addressing cEEG use, and fewer still are able to offer this service with administration by certified EEG technicians.1 The majority of institutions limit such monitoring to critically sick patients, and they do not truly provide cEEG monitoring but rather continuously acquire data and periodically interpret the tracings.

Our experience at Cleveland Clinic suggests that relatively short cEEG monitoring (two days or less) allows for efficient detection of abnormal findings, with abnormal findings identified about two-thirds of the time. These trends have remained consistent since the start of our cEEG service.

An Underutilized Tool

Conventional use of continuous EEG monitoring has long been carried out in dedicated pediatric epilepsy monitoring units. Use of bedside cEEG monitoring is also valuable in other hospitalized patients, where it serves as a surrogate marker for monitoring brain function. For instance, in patients with an alteration in mental status, cEEG is critical in detecting nonconvulsive seizures.2 In other situations, cEEG helps to evaluate predisposition for future seizures and to differentiate epileptic from nonepileptic paroxysmal events accurately.3 The capability of cEEG to detect these and many other abnormalities has a significant bearing on patient management and prognosis.2,4,5

Despite obvious benefits, cEEG is an underutilized tool in pediatric medicine due to its heavy dependence on technical, monetary and personnel resources. Recent data suggest there is a substantial gap between the clinical need and available resources.1 Clinical practices vary, and a consistent pathway of offering cEEG, including guidelines for clinical indications, is lacking.

Making cEEG a Priority

We have implemented significant changes during the past five years that have made state-of-the-art cEEG service possible for pediatric patients. These changes include:

• More thoughtfully allocating Epilepsy Center resources (EEG technicians, EEG machines)
• Establishing real-time monitoring capabilities within a central EEG monitoring unit
• Dedicating staff for timely interpretation of studies

Physicians within the Epilepsy Center have worked closely with the Center for Pediatric Neurology and other inpatient pediatric providers to offer cEEG service for carefully selected pediatric patients anywhere in the hospital. Continuous brain monitoring and interpretation optimize the care of sick patients and provide necessary information to help counsel families about future prognosis.

Our Experience: Monitoring for Timely Intervention

A review of pediatric (patients < 18 years) bedside cEEGs performed at our institution between January 2009 and July 2010 found that 377 studies were done on general pediatric floors and in pediatric and neonatal ICUs. The reasons for requesting cEEG were as follows:

• Evaluation of events concerning for seizures (41 percent)
• Previous seizures (28 percent)
• Screening for nonconvulsive seizures (14 percent)
• Altered mental state (12 percent)
• Ongoing status epilepticus (3 percent)
• Hypoxic ischemic encephalopathy cooling protocol, congenital heart disease and other reasons (2 percent)

Sixty percent of the cEEG studies showed abnormalities and demonstrated evidence of focal or generalized slowing, seizures, sharp waves or background suppression. In the cEEG studies demonstrating seizures, more than 40 percent of recorded seizures had no clinical signs, which underscores the importance of brain monitoring for timely intervention in treating silent seizures.

A more recent review found that 671 cEEG studies were performed from 2010 through 2012 in patients ranging from neonates to adolescents. As detailed in Figure 1, infants and toddlers were the most frequently studied group (57 percent across all three years), followed by adolescents (21 percent), young children (13 percent) and neonates (8 percent).

FIGURE 1. Distribution of Cleveland Clinic pediatric cEEG studies (N = 671) by age group over the period 2010-2012.

As detailed in Figure 2, the majority of studies were up to two days in duration (77 percent across all three years), a small proportion spanned two to five days (16 percent), and rarely were studies carried out beyond five days (7 percent).

FIGURE 2.Distribution of Cleveland Clinic pediatric cEEG studies (N = 671) by duration of study over the period 2010-2012.

As shown in Figure 3, the yield of cEEG studies in detecting abnormalities continues to remain high, with less than one-third of the studies (30 percent across all three years) classified as normal or only mildly abnormal. More than half of the studied patients (56 percent) were classified as having the highest degree of EEG abnormality (Abnormal III), which is reserved for patients with severe encephalopathy, structural lesions or epileptic activity. The remaining studies (14 percent) showed a moderately abnormal EEG.

FIGURE 3.Distribution of Cleveland Clinic pediatric cEEG studies (N = 671) by degree of abnormality detected over the period 2010-2012. None/ABI = normal/mildly abnormal; ABII = moderately abnormal; ABIII = severely abnormal.

A Collaborative Effort

Over the past few years, the pediatric cEEG program has become integral to patient care at Cleveland Clinic. It is a collaborative effort among pediatric care providers, including hospitalists, pediatric intensivists, pediatric neurologists, neonatologists and pediatric epilepsy teams.

We aim to maintain judicious utilization of this intensive and expensive procedure. Robust patient selection criteria and collaboration across these pediatric specialty areas, including the Epilepsy Center, are cornerstones of this effort.

Dr. Lachhwani is Chief of Neurology at Cleveland Clinic Abu Dhabi. His clinical interests lie in treating children with medically refractory epilepsy, functional neuroimaging, pediatric epilepsy surgery, and ICU monitoring of neonates and children.

References

1. Sanchez SM, Carpenter J, Chapman KE, et al; for the Pediatric Critical Care EEG Group. Pediatric ICU EEG monitoring: current resources and practice in the United States and Canada. J Clin Neurophysiol. 2013;30(2):156-160.

2. Abend NS, Topjian AA, Gutierrez-Colina AM, Donnelly M, Clancy RR, Dlugos DJ. Impact of continuous EEG monitoring on clinical management in critically ill children. Neurocrit Care. 2011;15(1):70-75.

3. Shahwan A, Bailey C, Shekerdemian L, Harvey AS. The prevalence of seizures in comatose children in the pediatric intensive care unit: a prospective video-EEG study. Epilepsia. 2010;51(7):1198-1204.

4. Abend NS, Dlugos DJ. Nonconvulsive status epilepticus in a pediatric intensive care unit. Pediatr Neurol. 2007;37(3):165-170.

5. Murray DM, Boylan GB, Ryan CA, Connolly S. Early EEG findings in hypoxic-ischemic encephalopathy predict outcomes at 2 years. Pediatrics. 2009;124(3):e459-e467.