Clinical UM Guideline

Subject: Electroencephalography and Video Electroencephalographic Monitoring
Guideline #:  CG-MED-46 Publish Date:    10/17/2018
Status: Revised Last Review Date:    09/13/2018



This document addresses electroencephalography (EEG) with and without video monitoring in the ambulatory setting and attended video EEG in a healthcare facility.


Clinical Indications

Ambulatory EEG

Medically Necessary:

Ambulatory EEG with or without video monitoring is considered medically necessary for any of the following indications:

Not Medically Necessary:

Ambulatory EEG with or without video monitoring is considered not medically necessary in all of the following circumstances including, but not limited to:

Attended EEG Video Monitoring in a Healthcare Facility

Medically Necessary:

Attended EEG with video monitoring in a healthcare facility is considered medically necessary for any of the following indications:

Not Medically Necessary:

Attended EEG with video monitoring in a healthcare facility is considered not medically necessary when an above criterion is not met and for all other indications.


The following codes for treatments and procedures applicable to this guideline are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.




Monitoring for identification and lateralization of cerebral seizure focus, electroencephalographic (eg, 8 channel EEG) recording and interpretation, each 24 hours


Monitoring for localization of cerebral seizure focus by cable or radio, 16 or more channel telemetry, combined electroencephalographic (EEG) and video recording and interpretation (eg, for presurgical localization), each 24 hours


Monitoring for localization of cerebral seizure focus by computerized portable 16 or more channel EEG, electroencephalographic (EEG) recording and interpretation, each 24 hours, unattended


Monitoring for localization of cerebral seizure focus by cable or radio, 16 or more channel EEG, electroencephalographic (EEG) recording and interpretation, each 24 hours, attended by a technologist or nurse


Unlisted neurological or neuromuscular diagnostic procedure [when specified as unattended home video electroencephalography]



ICD-10 Procedure



Monitoring of central nervous electrical activity, external approach



ICD-10 Diagnosis



Conversion disorder with seizures or convulsions


Other specified nonpsychotic mental disorders (psychogenic syncope)


Epilepsy and recurrent seizures


Absence epileptic syndrome


Juvenile myoclonic epilepsy (impulsive petit mal)


Other specified cerebrovascular diseases


Convulsions of newborn


Abnormal involuntary movements


Syncope and collapse


Convulsions, not elsewhere classified


Personal history of transient ischemic attack (TIA), cerebral infarction w/o residual deficit

Discussion/General Information

According to the Epilepsy Foundation, epilepsy affects 3 million people in the United States. Epileptic seizures can be related to a brain injury or genetics, but the cause is unknown for 70% of individuals with epilepsy. Epilepsy affects more than 300,000 children under the age of 15, and more than 90,000 young people in this group have seizures that are not treated adequately. The onset rate increases with aging, particularly if an older adult experiences a stroke or develops a brain tumor or Alzheimer's disease, all of which may result in seizures or epilepsy. Some reports indicate that more than 570,000 adults over the age of 65 suffer from the disorder. The Epilepsy Therapy Project notes that 10% of the population will have a seizure in their lifetime. In addition, the National Institute of Neurological Disorders and Stroke (NINDS) reports that 20% of persons with epilepsy have intractable seizures (seizures that do not respond to treatment).

An EEG test records continuous and prolonged electrical activity of the brain to assist in the evaluation and diagnosis of seizure disorders, epilepsy syndromes, and other conditions.

Ambulatory EEG monitoring in the outpatient setting (for example, a home environment) is a diagnostic test used to evaluate an individual in whom a seizure disorder is suspected but undefined by the person’s medical history, physical examination, or a routine (standard/resting) EEG. Ambulatory EEG recordings are utilized in the evaluation and differential diagnosis of other conditions including cardiac arrhythmias, hysterical episodes, sleep apnea, syncopal episodes, and transient ischemic attacks if these episodes are not identified by conventional studies. In most instances, a routine EEG performed at a clinic or outpatient epilepsy facility can identify brain activity specific to seizures; however, when routine EEG is inconclusive and the clinical history strongly suggests seizure activity, an ambulatory EEG may be indicated. Routine EEGs and ambulatory EEGs may not capture all the suspected events. In these instances it may be necessary to add video to the EEG. A video EEG records brainwave activity on an EEG and a video of what is going on at the same time. The purpose of this is to compare what is happening when a seizure or event occurs and compare the video to what the EEG records at the same time.

Ambulatory EEG

Ambulatory EEG testing provides a continuous recording of the brain’s electrical activity that can range from several hours to several days (typically 48 hours to 72 hours). In the outpatient setting (physician office, clinic), a set of electrodes with leads is secured to the person’s scalp and a recording unit is attached by a belt to the waist or on a shoulder harness. The technology has evolved such that portable recordings of up to 32 channels can record computer-assisted spike and seizure detection rates over several days. The computer software is designed with the goal to increase the chance of recording an ictal event or interictal (the period of time between seizures) epileptiform discharges (IEDs) during the person’s routine daily activities and sleep. The person being monitored and observers (family member, caregiver) have the opportunity to “tag” portions of the recording during clinical events using a push-button device. Some systems can be configured for polysomnography, with inputs available for monitoring simultaneous electrocardiogram (ECG), oximetry, pulse, respiratory, synchronous video recording, and other parameters. The gold standard for evaluating the large amount of data collected by a computer-assisted system is visual analysis at the end of the testing period by a highly trained individual (Foley, 2000; Seneviratne, 2013; Waterhouse, 2003).

Seizures vary to such an extent that epilepsy specialists frequently re-classify seizure types. Current classifications include two basic categories: primary generalized seizures and partial seizures (also referred to as focal seizures). Classifying the type of seizure assists the physician in diagnosing whether or not an individual has epilepsy or another condition and is important in the selection of appropriate anti-epileptic drug treatment. Generalized seizures are produced by electrical impulses throughout the entire brain, while partial seizures are produced (at least initially) by electrical impulses in a relatively small area of the brain (focus). The most common types of generalized seizures include: absence seizures (petit mal), atonic seizures, clonic seizures, generalized tonic-clonic (grand mal), myoclonic seizures, and tonic seizures. Focal seizures can be “simple” (not affecting awareness or memory) or “complex” (affecting awareness, memory, or behavior before, during, and immediately after the seizure). Seizure syndromes are specific to adults and children of all ages. Epilepsy syndromes in adults include, but are not limited to: temporal lobe epilepsy, primary generalized epilepsy, idiopathic focal epilepsy, and progressive myoclonic epilepsy. Epilepsy syndromes in children include, but are not limited to: febrile seizures, Landau-Kleffner Syndrome, Lennox-Gastaut Syndrome, and benign occipital epilepsy.

Routine EEG in persons with epilepsy may fail to demonstrate epileptiform activity. Ambulatory EEG is useful in documenting seizures when routine EEG is non-diagnostic. Confirmation of the clinical suspicion of epilepsy is most likely to occur when the person is experiencing daily to almost daily seizures. Studies looking at the diagnostic yield of ambulatory EEG indicate that 6% to 15% of ambulatory EEG recordings identify seizures (Waterhouse, 2003). Morris and colleagues (1994) retrospectively studied the ambulatory EEG results of 344 individuals referred to a community-based outpatient EEG service for further diagnostic evaluation using a 16-channel bipolar recording system. Ambulatory EEG was reviewed for the presence of user identified events, computer identified interictal and ictal abnormalities, and periodic time samples. A push-button recording that signified a clinical event was obtained in 166 individuals (48.3%); 41 (11.9%) of these recordings included a seizure and 125 (36.3%) showed no EEG changes during the habitual event. An EEG abnormality was identified by the computer in an additional 90 recordings (26.2%), for an overall clinical usefulness of 74.4%. Among the 191 individuals referred with previously normal routine EEGs, a total of 129 (67.5%) of these recordings were useful; 48 (25.1%) of these tracings were abnormal and an additional 81 push-button events (42.4%) showed no changes were recorded from background EEG. Tatum and colleagues (2001) retrospectively studied 502 participants evaluated with a computer-assisted 16-channel ambulatory EEG, identifying that 38.3% of seizures went unreported by participants with 8.5% demonstrating seizure activity during the recording period (mean=28.5 hours). Faulkner and colleagues (2012a) studied the value of outpatient ambulatory EEG in the diagnosis and classification of epilepsy. When compared to routine EEG, ambulatory EEG demonstrated a higher yield and diagnostic sensitivity.

Recognition of IEDs in the absence of recorded seizures can provide evidence to support a clinical diagnosis of epilepsy. Ambulatory EEG is highly specific in identifying the occurrence of electrical spikes in persons in whom the diagnosis of seizures is being considered. Schachter and colleagues (1998) evaluated the incidence of spikes and paroxysmal rhythmic events (PREs) using a computer-assisted ambulatory EEG monitoring system in a multicenter study of asymptomatic adults (n=135) without a history of migraine or a family history of epilepsy. Spikes and PREs were evident in the overnight ambulatory EEG of only 1 asymptomatic adult (0.7%). The incidences of spikes in 24 other subjects with a history of migraine and/or a family history of epilepsy were 12.5% and 13.3%, respectively. The ambulatory EEGs of these subjects were significantly more likely to show spikes than the ambulatory EEGs of subjects without migraine or a family history of epilepsy. Olson (2001) reviewed ambulatory EEGs of 167 children when seizure-like events occurred at least 3 days per week to determine why the ambulatory EEGs were performed and whether typical seizures were recorded. Most ambulatory EEGs were performed to discriminate between epileptic and non-epileptic seizures. Ten children were recorded to determine if they were having frequent subtle seizures or frequent IEDs. The remaining 157 children had discrete events. A total of 140 children (89%) had their typical spells recorded while 107 of these children (76%) had non-epileptic events. Average duration of recording was 1.9 days. Ambulatory EEG was successful in recording children's seizure-like events when parents reported events occurring at least 3 days per week. The procedure was well tolerated and there were few technical problems with prolonged recording time.

Additional case series and retrospective studies compare and confirm higher yields of epileptiform abnormalities and clinical events captured by ambulatory EEG compared to routine EEG (Saravanan, 2001). Investigators suggest that ambulatory EEG is superior to routine EEG in identifying both IEDs and seizures. Studies involving children and adults report a moderate to high diagnostic yield with ambulatory EEG in differentiating between seizures and non-epileptic events, quantifying seizure activity, and characterizing seizure type and location (Dash, 2012; Faulkner, 2012b; Hussain, 2013; Wirrell, 2008). Stefan and colleagues (2009; 2011) proposed the utility of outpatient ambulatory EEG (using a portable video camera in a domestic environment) as a more reliable, objective method of measuring seizure frequency to evaluate response to antiepileptic drug therapy in persons with medically refractory epilepsy.

Some persons in whom epilepsy is suspected have a normal routine or sleep-deprived EEG. An ambulatory EEG may increase the chance of detecting an epileptiform abnormality in these individuals and significantly impact clinical management. An estimated 12% to 25% of individuals who previously had a normal or non-diagnostic routine EEG have epileptiform activity on ambulatory EEG (Waterhouse, 2003). Liporace and colleagues (1998) conducted a multicenter prospective study comparing the usefulness of a sleep-deprived EEG versus a computer-assisted 16-channel ambulatory EEG in individuals with historical information consistent with epilepsy but with a normal or non-diagnostic initial routine EEG. A total of 46 participants had both a 30 to 60 minute sleep-deprived EEG and a computer-assisted ambulatory 24-hour EEG. Sleep-deprived EEG improved detection of epileptiform discharges by 24%, where ambulatory EEG improved detection of epileptiform discharges by 33%. Ambulatory EEG detected seizures in 7 of 46 (15%) participants, and in 3 participants the seizures were solely detected by the computer. Ambulatory EEG is invaluable in assessing nocturnal or sleep-related events because of its capacity to record an entire night of sleep and children can be monitored at home (Foley, 2000). In addition, an individual’s medical history may not reliably differentiate sleep-related events or disorders from epilepsy. An ambulatory EEG may record frequent arousals, suggesting sleep apnea, sustained daytime somnolence, or decreased rapid eye movement sleep latency (as in narcolepsy) and can assist in differentiating between an unsuspected sleep-related disorder and epilepsy (Waterhouse, 2003).

Ambulatory EEG is helpful at identifying seizures that are unrecognized or unreported by the individual and is easily accomplished on an outpatient basis. In both absence and focal seizures, individuals may experience brief alterations in the level of consciousness and impaired reaction time yet be unaware they are experiencing a seizure (Waterhouse, 2003). Keilson and colleagues (1987) studied 15 children, ages 5 to 16 years, with absence epilepsy using an 8-channel ambulatory cassette EEG. All 15 children demonstrated multiple paroxysms of generalized spike-and-wave discharges, most of which were asymptomatic. Therefore, ambulatory EEG may be useful in documenting the success or failure of a therapy in the treatment of absence seizures. In these situations, an ambulatory EEG of an untreated individual may show numerous daily seizures, yet normalize with adequate treatment.

Clinical events known as Psychogenic Non-epileptic Spells (PNES) (previously referred to as pseudoseizures) are non-epileptic seizures where the person perceives altered movement, emotion, sensation, or an experience similar to those involved with epilepsy. These events are without an EEG documented ictal association. PNES occur in as many as 20% of persons evaluated at inpatient epilepsy monitoring centers and in 5% to 20% of outpatient populations. Both PNES and epileptic seizures are concurrent in an estimated 10% to 60% of individuals with epilepsy (Waterhouse, 2003). In a retrospective review conducted by Morris and colleagues (1994), 36% (125 of 344) of participants in an outpatient study of ambulatory EEG activated the ambulatory event marker for events that were not associated with EEG changes. However, since some seizures are associated with minimal EEG changes or with movement and muscle artifacts that obscure the EEG, an ambulatory EEG is considered clinically appropriate as the initial screening procedure for non-epileptic events. Inpatient video EEG remains the gold standard to definitively diagnose non-epileptic PNES (LaFrance, 2013; Waterhouse, 2003).

Syncope or near-syncopal episodes may be evaluated with an ambulatory EEG if an ECG lead replaces one of the EEG channels (Lai, 1981). Although the underlying pathophysiological processes are distinct, seizures and syncope share some clinical characteristics which may lead to diagnostic confusion in addition to the fact that seizures and syncope may coexist in a given individual (Zaidi, 2000). Although arrhythmias have been diagnosed with continuous ambulatory EEG/ECG recording, a retrospective record review of epileptiform abnormalities in 500 individuals found epileptiform abnormalities in 1.5% of individuals with syncope and in none without a clear history of episodic complaints (Bridgers and Ebersole, 1985).

Evaluating adequate ictal and interictal EEG data is vital in facilitating localization of seizures in localization-related epilepsy (Kelly, 2011). The peer-reviewed literature reviewing the use of outpatient ambulatory EEG monitoring as the sole EEG modality in the presurgical evaluation of persons with medically refractory epilepsy consists of a single case study (Schomer, 1999) and a small case series (Chang, 2002) from the same treatment center. Chang and colleagues (2002) reported on 7 persons who underwent surgery for temporal lobe epilepsy after presurgical EEG monitoring was performed exclusively in the home setting. When compared to a group of 14 persons with similar characteristics (including age, epilepsy, duration, seizure frequency and number of antiepileptic drugs tried before evaluation) who underwent inpatient video EEG monitoring, the number of seizures captured and mean recording duration were less in the 7 persons who were evaluated with ambulatory EEG. The small, nonrandomized sample from a single institution and the retrospective design of the study make it difficult to draw conclusions regarding optimal criteria for selecting persons for ambulatory EEG in the presurgical workup. Ambulatory EEG, even with concomitant video recording, has major limitations in the outpatient setting, including the inability to taper antiepileptic drugs due to safety concerns in the home setting and lack of assessment/supervision by an experienced observer if or when a seizure occurs (Velis, 2007).

Ambulatory EEG is an outpatient test measuring the electrical activity in the brain and has been used for many years in the evaluation and diagnosis of seizure disorders, epilepsy syndromes, and other conditions. It is considered a safe procedure in the home setting and the test causes no discomfort to the individual as the electrodes only record activity and do not produce any electrical current.

Video EEG

Inpatient video EEG monitoring is considered the preferred mode and gold standard of practice in presurgical EEG testing by most epilepsy treatment centers because it accurately differentiates epileptic from non-epileptic events and provides data to localize the epileptogenic zone in candidates for epilepsy surgery (Seneviratne, 2013; Wirrell, 2008).

In a 2009 study by Moien-Afshari and colleagues, 50 participants had video EEG and were monitored in an inpatient setting for the discontinuation of antiepileptic drugs. In 90% of the participants, neurological exam was normal and 24% of participants had a normal routine EEG prior to admission. During the admission and video EEG, 31 participants had recorded epileptic events and 23 were identified as candidates for epilepsy surgery. The mean hospital stay for monitoring was 4.4 days. Despite the medical management being changed in 74% of the participants, this study has limitations including a lack of control group and a small sample size which may underestimate complications.

In a 2013 study by Kumar-Pelayo, the charts of 100 participants were reviewed to determine the goal of inpatient video EEG and analyze the outcome. The reasons for admission were: to characterize events as either epileptic or nonepileptic (n=41), to localize epileptic foci (n=23), to characterize the epilepsy syndrome (n=32), and to attempt safe antiepileptic drug adjustment (n=4). For classification of the events as either epileptic or nonepilepctic, determination was made in 29 of the participants. Localization of an epileptic focus was achieved in all 23 of the participants admitted for that purpose. Of the 23 participants admitted for seizure localization, 15 proceeded with surgical evaluation and 5 of those underwent craniotomy within 6 months. Epilepsy syndrome was characterized in 22 participants. Medication adjustment was made in 3 participants. Inpatient length of stay ranged from 1 to 8 days.

The peer-reviewed literature discussing the selection process of appropriate candidates for temporal lobe epilepsy resection surgery consistently recommends that surgery is only undertaken after long-term video EEG monitoring in an epilepsy unit. Ambulatory EEG in the outpatient setting provides insufficient information for localizing both interictal and ictal onset zones and does not allow for the person to be subjected to provocative measures such as medication tapering or reinstitution, sleep deprivation, hyperventilation, or photic stimulation in a controlled environment, all techniques that increase the likelihood of capturing reliable presurgical epileptiform activity (Mansouri, 2012).

Status epilepticus is a condition in which individuals have prolonged seizures or when seizures occur too close together for them to recover in between episodes. However, not all seizure activity occurs in the same way. Due to a lack of convulsions, nonconvulsive status epilepticus may be difficult to diagnose. This is even more difficult for individuals who are comatose with unexplained and continued altered consciousness. Continuous video EEG is a way to capture these types of seizures. In a 2004 study by Claassen and colleagues, a total of 572 individuals were reviewed for detection of subclinical seizures or evaluated for an unexplained decrease in their level of consciousness. Using continuous video EEG monitoring, seizures were found in 110 individuals. Of the 110 individuals found to have seizure activity, 101 of them were noted to be nonconvulsive. The majority of the individuals (88%) had seizures detected within the first 24 hours of EEG monitoring. A 2013 literature analysis by the European Society of Intensive Care Medicine (Claassen, 2013) sought to establish recommendations on the use of EEG in the intensive care unit setting. With 42 studies included in the review, the consensus was to recommend EEG in status epilepticus and in ruling out nonconvulsive status epilepticus. This technology can be important in managing and directing care.

There have been recent technologic developments for EEG which includes the use of continuous EEG and synchronized video recording in the home or ambulatory setting. The technology is performed to supplement descriptions of seizure activity by care takers.

In a 2014 study by Goodwin and colleagues, 130 participants who had previous ambulatory EEG testing were offered video EEG to be done in the home setting. A total of 45 participants (accepted the offer of video EEG in the home setting to investigate the nature of undiagnosed paroxysmal events. Of the 45 participants who used the video EEG in the home setting, an ictus occurred in 34 participants. Of those 34 participants, 17 had a habitual attack which was captured by video. A total of 14 participants who had a recorded attack had information which was useful in interpreting the ambulatory EEG. Failure to capture attacks on video was attributed to failure to operate the equipment successfully and events being too brief to set up the video in time. The quality of the video was deemed to be satisfactory in all 17 instances in which an attack was captured on video. While this study provides useful information from the home video recordings, there are limitations to outpatient video EEG including some families have less familiarity with the technology and certain participants are more or less likely to be observed closer by family members therefore there is a varying chance of capturing data on video.

In a 2016 retrospective review by Lawley and colleagues, review of 88 ambulatory video EEG studies was completed in order to assess the diagnostic utility. Clinical events (defined in this study as epileptic seizures, physiologic nonepileptic events, or psychogenic nonepileptic seizures) occurred during 55 of the ambulatory video EEG studies (62.5%). In 26 of these, at least one event was also clearly seen on video recording. In 6 of the ambulatory video EEG studies which captured events, a diagnosis of epileptic seizures was confirmed. The remaining 49 studies which captured events had no associated changes in the underlying ambulatory video EEG. The authors noted an overall diagnostic utility of 67%. Results of ambulatory video EEG influenced medical management in 34 cases, including change in antiepileptic medication or adoption of an alternate management strategy when a different diagnosis was suggested. Management strategy was changed in 75.0% of cases where an event occurred but was not seen on video. Two studies were unsuccessful because of technical equipment problems (failure to activate the camcorder). And while this study has limitations which include its retrospective design and potential for selection bias due to referral for ambulatory video EEG, the ambulatory video EEG appears to have a high diagnostic utility and continuing advances in technology may help in the future with technical factors and potential loss of data.

A 2016 retrospective comparative study by Biswas and colleagues looked at 28 individuals who had inpatient video EEG and compared the quality of the EEG to 28 individuals who had ambulatory video EEG. Comparisons were made to visibility of body part of interest, visibility of eyes, time of events captured, level of illumination, contrast (discerning the subject from the environment), sound quality and clarity of picture when amplified to 200%. In the majority of compared variables (the visibility of body part of interest, visibility of eyes, time of the event, and sound quality) there were no statistically significant differences between ambulatory video EEG and inpatient video EEG. When amplified, the picture quality showed to be slightly better on the ambulatory video EEG group. Statistically significant differences were noted in lighting and contrast distributions. The authors contributed this to lights being switched off more often at night in the inpatient setting. While this study is based on a small number of participants, it should be noted that participants were excluded from the analysis where no events were captured and it was difficult to find an adequate number of participants with a captured event since the study was based solely on video quality by analyzing captured events.

A 2017 study by Kandler and colleagues reported on a comparison between ambulatory video EEG to inpatient video EEG in terms of diagnostic efficiency and quality of video EEG recording. In this prospective study 41 participants received ambulatory video EEG while 64 participants received video EEG monitoring in the inpatient setting. Neither group of participants were subjected to anti-epileptic medication withdrawal or sleep deprivation and none were being assessed for epilepsy surgery. Of the participants referred to differentiate between epilepsy and non-epileptic attack disorder, the diagnostic question was answered in 10/15 (67%) of ambulatory video EEGs and 27/43 (63%) of inpatient video EEGs. On recordings where attacks occurred, all were clearly seen on video in 19/25 (76%) of ambulatory video EEGs and 22/31 (71%) of inpatient video EEGs. At least some attacks were visualized on 22/25 (88%) of video EEGs and 26/31 (84%) of inpatient video EEGs. The nighttime video was rated as good quality in 35/41 (85%) of video EEGs and in 60/64 (94%) of inpatient video EEGs. Accurate interpretation EEG was achieved in 40/41 (97%) of ambulatory video EEGs and 58/64 (91%) of inpatient video EEGs. Ambulatory video EEG equipment was reported as difficult to use by four participants, but diagnostic information was lost in only one participant. A valid concern regarding the use of ambulatory video EEG is the loss of diagnostic data, however equipment failure can also occur in a facility setting. In this particular study, while the group size was small, the comparisons of diagnostic yield between the two groups was similar.

It should be noted that the published studies of ambulatory video EEG exclude participants where seizure medications are to be withdrawn or modified. Also excluded are participants considered for epilepsy surgery who need localization of the seizure focus. With continued advances in technology of video recording devices and more familiarity of the general population with the use of recording devices, results from ambulatory video EEG continue to improve and show similar results when compared to inpatient video EEG recording.


Absence seizure: A staring spell, usually brief (less than 15 seconds) in duration due to abnormal electrical activity of the brain; commonly called a petit mal seizure.

Electroencephalography (EEG): A test that involves recording of the electrical activity of the brain (brain waves).

Epilepsy: A condition of the brain where an individual is prone to repeated seizures.

Epileptic seizure: A brief occurrence of signs and/or symptoms such as sudden and involuntary jerk of a hand, arm, or whole body, a strange smell (such as burnt rubber), a sensation in the stomach, a ringing sound that keeps increasing in volume, staring into space, or convulsive movements as a result of a primary change to the electrical activity (abnormally excessive) in the brain.

Epileptiform activity: Changes in the brain’s electrical activity that are commonly seen in people who have epilepsy.

Focal seizure: A seizure that begins with an electrical discharge in a relatively small area (called the focus) of the brain; previously referred to as a partial or localization-related seizure. In most cases, the cause is unknown, but may be related to a brain infection, head injury, stroke, or a brain tumor.

Generalized seizure: A seizure that begins with a widespread electrical discharge involving both sides of the brain at once.

Lennox-Gastaut Syndrome: An epilepsy syndrome with an age of onset of 3-10 years characterized by multiple seizure types (including atonic, tonic, tonic-clonic and atypical absence seizures), cognitive impairment and specific EEG features of diffuse slow spike and wave as well as paroxysmal fast activity during sleep.

Medically refractory (intractable) epilepsy: Failure of an adequate trial of two tolerated antiepileptic drug schedules to achieve sustained seizure freedom. These should be appropriately chosen and can be monotherapy or in combination.

Myoclonic seizure: Sudden, brief (less than 100 millisecond) and almost shock-like involuntary single or multiple jerks due to abnormal or excessive or synchronous neuronal activity; associated with polyspikes on EEG.

Nonconvulsive status epilepticus: Refers to a prolonged seizure that manifests as an altered mental state as opposed to convulsions seen in tonic-clonic seizures.

Primary generalized seizure: A seizure that results from abnormal electrical activity of both sides of the brain at the same time.

Psychogenic Non-epileptic Spells: A non-epileptic event that imitates a seizure and may include rhythmic movements, unresponsiveness, or other symptoms similar to those caused by epilepsy, but without an electrographic association.

Seizure: An excessive surge of electrical activity in the brain, usually lasting from a few seconds up to a few minutes, causing a wide range of symptoms or effects depending on which parts of the brain are involved in the abnormal electrical activity.

Status epilepticus: A condition in which a seizure lasts too long or when seizures occur close together and the individual doesn’t recover between seizures.

Tonic seizures: An epileptic seizure characterized by abrupt generalized muscle stiffening than can result in a fall, usually lasting less than a minute with rapid recovery.

Tonic-clonic seizure: A seizure of sudden onset involving generalized stiffening and subsequent rhythmic jerking of the limbs.


Peer Reviewed Publications:

  1. Biswas S, Luz R, Brunnhuber F. Home video telemetry vs inpatient telemetry: a comparative study looking at video quality. Clin Neurophysiol Pract 2016; 1:38-40.
  2. Bridgers SL, Ebersole JS. Ambulatory cassette EEG in clinical practice. Neurology. 1985; 35(12):1767-1768.
  3. Brigo F. An evidence-based approach to proper diagnostic use of the electroencephalogram for suspected seizures. Epilepsy Behav. 2011; 21(3):219-222.
  4. Britton JW. Syncope and seizures-differential diagnosis and evaluation. Clin Auton Res. 2004; 14(3):148-159.
  5. Brunnhuber F, Amin D, Nguyen Y, et al. Development, evaluation and implementation of video-EEG telemetry at home. Seizure. 2014; 23(5):338-343.
  6. Casson AJ, Smith S, Duncan JS, et al. Wearable EEG: what is it, why is it needed and what does it entail? Conf Proc IEEE Eng Med Biol Soc. 2008; 2008:5867-5870.
  7. Casson A, Yates D, Smith S, et al. Wearable electroencephalography. What is it, why is it needed, and what does it entail? IEEE Eng Med Biol Mag. 2010; 29(3):44-56.
  8. Chang BS, Ives JR, Schomer DL, Drislane FW. Outpatient EEG monitoring in the presurgical evaluation of patients with refractory temporal lobe epilepsy. J Clin Neurophysiol. 2002; 19(2):152-156.
  9. Claassen J, Mayer SA, Kowalski RG, et al. Detection of electrographic seizures with continuous EEG monitoring in critically ill patients. Neurology. 2004; 62(10):1743-1748.
  10. Dash D, Hernandez-Ronquillo L, Moien-Afshari F, Tellez-Zenteno JF. Ambulatory EEG: a cost-effective alternative to inpatient video-EEG in adult patients. Epileptic Disord. 2012; 14(3):290-297.
  11. Engel J Jr, Wiebe S, French J, et al. Practice parameter: temporal lobe and localized neocortical resections for epilepsy. Epilepsia. 2003; 44(6):741-751.
  12. Faulkner HJ, Arima H, Mohamed A. Latency to first interictal epileptiform discharge in epilepsy with outpatient ambulatory EEG. Clin Neurophysiol. 2012a; 123(9):1732-1735.
  13. Faulkner HJ, Arima H, Mohamed A. The utility of prolonged outpatient ambulatory EEG. Seizure. 2012b; 21(7):491-495.
  14. Foley CM, Legido A, Miles DK, et al. Long-term computer-assisted outpatient electroencephalogram monitoring in children and adolescents. J Child Neurol. 2000; 15(1):49-55.
  15. Gilliam F, Kuzniecky R, Faught E. Ambulatory EEG monitoring. J Clin Neurophysiol. 1999; 16(2):111-115.
  16. Goodwin E, Kandler RH, Alix JJ. The value of home video with ambulatory EEG: a prospective service review. Seizure. 2014; 23(6):480-482.
  17. Hammill SC. Value and limitations of noninvasive assessment of syncope. Cardiol Clin. 1997; 15(2):195-218.
  18. Hussain N, Gayatri N, Blake A, et al. Ambulatory electroencephalogram in children: a prospective clinical audit of 100 cases. J Pediatr Neurosci. 2013; 8(3):188-191.
  19. Kandler R, Ponnusamy A, Wragg C. Video ambulatory EEG: A good alternative to inpatient video telemetry?
  20. Seizure. 2017; 47:66-70.
  21. Keilson MJ, Hauser WA, Magrill JP, Tepperberg J. Ambulatory cassette EEG in absence epilepsy. Pediatr Neurol. 1987; 3(5):273-276.
  22. Kelly KM, Chung SS. Surgical treatment for refractory epilepsy: review of patient evaluation and surgical options. Epilepsy Res Treat. 2011; 2011:303624.
  23. Kumar-Pelayo M, Oller-Cramsie M, Mihu N, Harden C. Utility of video-EEG monitoring in a tertiary care epilepsy center. Epilepsy Behav. 2013; 28(3):501-503.
  24. Lagerlund TD, Cascino GD, Cicora KM, Sharbrough FW. Long-term electroencephalographic monitoring for the diagnosis and management of seizures. Mayo Clin Proc. 1996; 71(10):1000-1006.
  25. Lai CW, Ziegler DK. Syncope problem solved by continuous ambulatory simultaneous EEG/ECG recording. Neurology. 1981; 31(9):1152-1154.
  26. Lawley A, Evans S, Manfredonia F, Cavanna AE. The role of outpatient ambulatory electroencephalography in the diagnosis and management of adults with epilepsy or nonepileptic attack disorder: A systematic literature review. Epilepsy Behav. 2015; 53:26-30.
  27. Lawley A, Manfredonia F, Cavanna AE. Video-ambulatory EEG in a secondary care center: A retrospective evaluation of utility in the diagnosis of epileptic and nonepileptic seizures. Epilepsy Behav. 2016;57(Pt A):137-140.
  28. Liporace J, Tatum W 4th, Morris GL 3rd, French J. Clinical utility of sleep-deprived versus computer-assisted ambulatory 16-channel EEG in epilepsy patients: a multi-center study. Epilepsy Res. 1998; 32(3):357-362.
  29. Mansouri A, Fallah A, Valiante TA. Determining surgical candidacy in temporal lobe epilepsy. Epilepsy Res Treat. 2012; 2012:706917.
  30. Mendiratta A. Clinical neurophysiology of epilepsy. Curr Neurol Neurosci Rep. 2003; 3(4):332-340.
  31. Miller JW, Cole AJ. Is it necessary to define the ictal onset zone with EEG prior to performing resective epilepsy surgery? Epilepsy Behav. 2011; 20(2):178-181.
  32. Moien-Afshari F, Griebel R, Sadanand V, et al. Safety and yield of early cessation of AEDs in video-EEG telemetry and outcomes. Can J Neurol Sci. 2009; 36(5):587-592.
  33. Morris GL. The clinical utility of computer-assisted ambulatory 16 channel EEG. J Med Eng Technol. 1997; 21(2):47-52.
  34. Morris GL, Galezowska J, Leroy R, North R. The results of computer-assisted ambulatory 16-channel EEG. Electroencephalogr Clin Neurophysiol. 1994; 91(3):229-231.
  35. Olson DM. Success of ambulatory EEG in children. J Clin Neurophysiol. 2001; 18(2):158-161.
  36. Saravanan K, Acomb B, Beirne M, Appleton R. An audit of ambulatory cassette EEG monitoring in children. Seizure. 2001; 10(8):579-582.
  37. Schachter SC, Ito M, Wannamaker BB, et al. Incidence of spikes and paroxysmal rhythmic events in overnight ambulatory computer-assisted EEGs of normal subjects: a multicenter study. J Clin Neurophysiol. 1998; 15(3):251-255.
  38. Schomer DL. Ambulatory EEG telemetry: how good is it? J Clin Neurophysiol. 2006; 23(4):294-305.
  39. Schomer DL, Ives JR, Schachter SC. The role of ambulatory EEG in the evaluation of patients for epilepsy surgery. J Clin Neurophysiol. 1999; 16(2):116-129.
  40. Seneviratne U, Mohamed A, Cook M, D’Souza W. The utility of ambulatory electroencephalography in routine clinical practice: a critical review. Epilepsy Res. 2013; 105(1-2):1-12.
  41. Seneviratne U, Rahman Z, Diamond A, Brusco M. The yield and clinical utility of outpatient short-term video-electroencephalographic monitoring: a five-year retrospective study. Epilepsy Behav. 2012; 25(3):303-306.
  42. Stefan H, Hopfengärtner R. Epilepsy monitoring for therapy: challenges and perspectives. Clin Neurophysiol. 2009; 120(4):653-658.
  43. Stefan H, Kreiselmeyer G, Kasper B, et al. Objective quantification of seizure frequency and treatment success via long-term outpatient video-EEG monitoring: a feasibility study. Seizure. 2011; 20(2):97-100.
  44. Tatum WO, Winters L, Gieron M, et al. Outpatient seizure identification: results of 502 patients using computer-assisted ambulatory EEG. J Clin Neurophysiol. 2001; 18(1):14-19.
  45. Waterhouse E. New horizons in ambulatory electroencephalography. IEEE Eng Med Biol Mag. 2003; 22(3):74-80.
  46. Wirrell E, Kozlik S, Tellez J, et al. Ambulatory electroencephalography (EEG) in children: diagnostic yield and tolerability. J Child Neurol. 2008; 23(6):655-662.
  47. Worrell GA, Lagerlund TD, Buchhalter JR. Role and limitations of routine and ambulatory scalp electroencephalography in diagnosing and managing seizures. Mayo Clin Proc. 2002; 77(9):991-998.
  48. Zaidi A, Clough P, Cooper P, et al. Misdiagnosis of epilepsy: many seizure-like attacks have a cardiovascular cause. J Am Coll Cardiol. 2000; 36(1):181-184.

Government Agency, Medical Society and Other Authoritative Publications:

  1. American Academy of Pediatrics (AAP). Subcommittee on Febrile Seizures. Neurodiagnostic evaluation of the child with a simple febrile seizure. Pediatrics. 2011; 127(2):389-394.
  2. Centers for Medicare and Medicaid Services (CMS). National Coverage Determinations. Available at: Accessed on July 25, 2018.
    • Ambulatory EEG Monitoring. NCD #160.22. Effective June 12, 1984.
    • Telephone Transmission of Electroencephalograms (EEGs). NCD #160.21. Effective date not posted.
  3. Claassen J, Taccone FS, Horn P, et al. Recommendations on the use of EEG monitoring in critically ill patients: consensus statement from the neurointensive care section of the ESICM. Intensive Care Med. 2013; 39(8):1337-1351.
  4. Krumholz A, Wiebe S, Gronseth G, et al. Evidence-based guideline: Management of an unprovoked first seizure in adults Report of the Guideline Development Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2015; 84(16):1705–1713.
  5. LaFrance WC Jr, Baker GA, Duncan R, et al. Minimum requirements for the diagnosis of psychogenic nonepileptic seizures: a staged approach. A report from the International League Against Epilepsy Nonepileptic Seizures Task Force. Epilepsia. 2013; 54(11):2005-2018.
  6. National Institute of Neurological Disorders and Stroke (NINDS). Neurological diagnostic tests and procedures. Last modified July 6, 2018. Available at: Accessed on October 1, 2018.
  7. Velis D, Plouin P, Gotman J, da Silva FL.; ILAE DMC Subcommittee on Neurophysiology. Recommendations regarding the requirements and applications for long-term recordings in epilepsy. Epilepsia. 2007; 48(2):379-384.
Websites for Additional Information
  1. American Academy of Neurology (AAN). Available at: Accessed on July 25, 2018.
  2. American Association of Neurological Surgeons (AANS). Available at: Accessed on July 25, 2018.
  3. Epilepsy Foundation. Available at: Accessed on July 25, 2018.






Medical Policy & Technology Assessment Committee (MPTAC) review. Title change. Revision to the ambulatory EEG MN statement to include with or without video monitoring. Revision to NMN statement of ambulatory EEG by adding “Antiepileptic drug treatment withdrawal or modification in individuals because the risk of seizure precipitation would require immediate medical intervention.” Revision to the MN statement for attended EEG video monitoring in a healthcare facility by adding “withdrawal. ” Updated Description, Discussion/General Information, Definitions and References sections. Updated Coding section; added CPT 95999.



MPTAC review. Added outpatient video EEG to scope of document. Updated Description, Discussion/General Information, and References sections. Title changed to “Ambulatory Electroencephalography and Video Electroencephalography.” The document header wording updated from “Current Effective Date” to “Publish Date.”



MPTAC review. Updated References section.



MPTAC review. Updated Discussion/General Information and References sections. Updated formatting in Clinical Indications section. Removed ICD-9 codes from Coding section.



MPTAC review. Clarification to Medically Necessary Statement.



MPTAC review. Added Medically Necessary indication for “Non-convulsive status epilepticus or status epilepticus” for video EEG. Updated Discussion/General Information, Definitions, and References sections.



MPTAC review. Expanded scope of document to include video EEG, inpatient and observation status. Added Medically Necessary and Not Medically Necessary criteria for inpatient and observation status for video EEG. Title changed. Clarification to Not Medically Necessary statement regarding Ambulatory EEG. Updated Description, Coding, Discussion/General Information, and References.



MPTAC review. Updated Discussion/General Information, References, and Websites for Additional Information sections.



Clarified Discussion and Definitions concerning pseudoseizures. Updated References and Websites for Additional Information sections.



MPTAC review. Initial document development.