Comprehensive Comprehensive Video EEG Video EEG monitoring monitoring JWM Neurology JWM Neurology Kate Kobza, MD Kate Kobza, MD August 2006 August 2006
Feb 12, 2016
Comprehensive Video Comprehensive Video EEG monitoringEEG monitoring
JWM NeurologyJWM NeurologyKate Kobza, MDKate Kobza, MD
August 2006August 2006
Why do we need it?Why do we need it?
Limitations of routine EEG:Limitations of routine EEG:
Limited samplingLimited sampling An EEG is a sampling of brain activity An EEG is a sampling of brain activity
occurring occurring at the timeat the time of the recording of the recording Seizures and Seizures and spellsspells are paroxysmal and may are paroxysmal and may
be missed on a short studybe missed on a short study
No video to correlate patient No video to correlate patient behavior with suspicious EEG behavior with suspicious EEG changeschanges
Limitations of routine EEG:Limitations of routine EEG:
Yield of a single routine scalp EEG is 50%Yield of a single routine scalp EEG is 50% Certain artifacts and normal variants can Certain artifacts and normal variants can
be confused with epileptiform dischargesbe confused with epileptiform discharges Some EEG abnormalities do not have a Some EEG abnormalities do not have a
close correlation with clinical close correlation with clinical seizuresseizures
Limitations of routine EEG:Limitations of routine EEG:
Pathophysiologically – epileptic seizures are Pathophysiologically – epileptic seizures are characterized by an excessive, disorderly, characterized by an excessive, disorderly, neuronal dischargeneuronal discharge
An EEG study may disclose epileptiform An EEG study may disclose epileptiform abnormalities which have a abnormalities which have a high correlationhigh correlation with with occurrence of epileptic seizuresoccurrence of epileptic seizures
The only way to definitively prove The only way to definitively prove epilepsy is to record a seizureepilepsy is to record a seizure
What does a video EEG What does a video EEG study consist of?study consist of?
MethodologyMethodology EEG electrodes are attached to EEG electrodes are attached to
the scalp with gluethe scalp with glue ECG electrodes are placedECG electrodes are placed Patient is moved to a room with Patient is moved to a room with
video monitoringvideo monitoring Patient and family are given an Patient and family are given an
alarm to push with any spellalarm to push with any spell Trained nurses and staff Trained nurses and staff
respond to alarms to observe respond to alarms to observe patient and treat if necessarypatient and treat if necessary
MethodologyMethodology
Miscellaneous options:Miscellaneous options: Antiepileptic medications may be discontinued Antiepileptic medications may be discontinued
or decreasedor decreased Known inducers of events may be performedKnown inducers of events may be performed
• Sleep deprivationSleep deprivation• Suggestion (important in nonepileptic events)Suggestion (important in nonepileptic events)
Extra electrodes may be addedExtra electrodes may be added• SphenoidalSphenoidal• Foramen ovaleForamen ovale
MethodologyMethodology Multi-channel long term EEG recording Multi-channel long term EEG recording
with split screen video recordingwith split screen video recording Digital storage of EEG and video data that Digital storage of EEG and video data that
can be reviewed latercan be reviewed later Performed under close Performed under close
monitoring of trained monitoring of trained technologists and nursestechnologists and nurses
Study is reviewed by a Study is reviewed by a trained neurologist or trained neurologist or epileptologistepileptologist
Outpatient settingsOutpatient settings Represents a Represents a partially controlledpartially controlled
environmentenvironment Useful for:Useful for:
Minor or non-convulsive seizuresMinor or non-convulsive seizures Diagnostic purposes onlyDiagnostic purposes only
Benefits:Benefits: Less costlyLess costly
Drawbacks:Drawbacks: Invasive electrodes not possibleInvasive electrodes not possible No medication withdrawal possibleNo medication withdrawal possible
Inpatient settingsInpatient settings Completely Completely controlled environmentcontrolled environment Useful for:Useful for:
Major or convulsive seizuresMajor or convulsive seizures Medication withdrawal possibleMedication withdrawal possible
Benefits:Benefits: Other tests: Blood sugars, SPECT possibleOther tests: Blood sugars, SPECT possible Inducers can be used, if presentInducers can be used, if present Invasive electrode monitoring possibleInvasive electrode monitoring possible Intracranial EEG possibleIntracranial EEG possible
Drawbacks:Drawbacks: ExpensiveExpensive
Who orders a study?Who orders a study?What patients might be What patients might be
candidates?candidates?
Primarily Primarily neurologists order neurologists order video EEG studiesvideo EEG studies
Video EEG can be Video EEG can be ordered on infants, ordered on infants, children, and adultschildren, and adults
Indications for video Indications for video EEG monitoringEEG monitoring
Common indications:Common indications:
Follow up of borderline or nonconclusive routine Follow up of borderline or nonconclusive routine EEGsEEGs
Diagnosis of recurrent Diagnosis of recurrent spellsspells Classification of seizure typeClassification of seizure type Quantification of interictal epileptiform activityQuantification of interictal epileptiform activity Preoperative evaluation of surgical candidatesPreoperative evaluation of surgical candidates Evaluation of patient in coma as treatments for Evaluation of patient in coma as treatments for
status epilepticusstatus epilepticus
Follow-up borderline EEGFollow-up borderline EEG Allows for prolonged Allows for prolonged
collection of digital collection of digital EEGEEG
Areas of uncertainty Areas of uncertainty (i.e. artifact vs. (i.e. artifact vs. abnormality) can be abnormality) can be correlated with video correlated with video material for material for clarificationclarification
Aids in diagnosis of Aids in diagnosis of spellsspells::
Causes other than epileptic seizures:Causes other than epileptic seizures: SyncopeSyncope Sleep apneaSleep apnea Periodic movements of sleepPeriodic movements of sleep Non-epileptic seizuresNon-epileptic seizures Breath-holding spellsBreath-holding spells MigraineMigraine
Other uses:Other uses: Characterization or Characterization or
any repetitive or any repetitive or stereotyped behaviorstereotyped behavior
autonomic changes in autonomic changes in infantsinfants
repetitive behaviors in repetitive behaviors in the ICU settingthe ICU setting
unexplained unexplained nocturnal eventsnocturnal events
Characterization of seizuresCharacterization of seizures
Accurate diagnosis Accurate diagnosis and classification of and classification of seizures is essential seizures is essential for proper for proper therapeutic therapeutic interventionintervention
Medication choices Medication choices are driven by are driven by seizure classificationseizure classification
Classification of seizure typesClassification of seizure types
GeneralizedGeneralized AbsenceAbsence Generalized tonic, clonic, or atonicGeneralized tonic, clonic, or atonic MyoclonicMyoclonic
Partial onsetPartial onset Simple or complexSimple or complex Secondary generalizationSecondary generalization
Non epilepticNon epileptic
Examples of seizure typesExamples of seizure types
Complex partialComplex partial Generalized tonic-clonicGeneralized tonic-clonic NonepilepticNonepileptic
Complex partialComplex partial
Generalized tonic-clonicGeneralized tonic-clonic
NonepilepticNonepileptic
Diagnosis of non-epileptic events: Diagnosis of non-epileptic events: PseudoseizuresPseudoseizures
StudiesStudies11 have shown that 22% of patients with have shown that 22% of patients with medically intractable seizures studied by video medically intractable seizures studied by video EEG monitoring had nonepileptic eventsEEG monitoring had nonepileptic events
Approximately 1/3 of patients studied at video Approximately 1/3 of patients studied at video monitoring centers have nonepileptic eventsmonitoring centers have nonepileptic events
The majority of patients with nonepileptic events The majority of patients with nonepileptic events have been inappropriately treated with have been inappropriately treated with antiepileptic medications for yearsantiepileptic medications for years
11 Matson et al. Matson et al.
Nonepileptic eventsNonepileptic events Video EEG monitoring provides evidence Video EEG monitoring provides evidence
to support medication choicesto support medication choices• Allows safe discontinuation of antiepileptic drugsAllows safe discontinuation of antiepileptic drugs
Information can be used when discussing Information can be used when discussing a diagnosis of pseudoseizure with patientsa diagnosis of pseudoseizure with patients
• Many patients are relieved by diagnosisMany patients are relieved by diagnosis• Many others are doubtful as they have been told Many others are doubtful as they have been told
for many years that they have epilepsyfor many years that they have epilepsy This is used to as a treatment modalityThis is used to as a treatment modality
Nonepileptic eventsNonepileptic events Majority of patients with nonepileptic Majority of patients with nonepileptic
events also experience epileptic seizuresevents also experience epileptic seizures Video EEG can quantitate frequency of Video EEG can quantitate frequency of
each typeeach type Aids in education of family members about Aids in education of family members about
clinical differencesclinical differences• Avoid abuse of resourcesAvoid abuse of resources• Limit health provider callsLimit health provider calls• Avoid abuse (overuse) of antiepileptic drugsAvoid abuse (overuse) of antiepileptic drugs
Quantification of interictal Quantification of interictal epileptiform activityepileptiform activity
Quantify the number of seizures per dayQuantify the number of seizures per day Helpful for:Helpful for:
Absence seizures Absence seizures • Helpful in decision to stop medicationsHelpful in decision to stop medications
Nonconvulsive seizuresNonconvulsive seizures Document efficacy of suppressive Document efficacy of suppressive
medicationsmedications
Things we don’t like to hear as a passenger.Things we don’t like to hear as a passenger.
Localization of epileptogenic focusLocalization of epileptogenic focus
Useful in patients with Useful in patients with intractable epilepsy as intractable epilepsy as part of a presurgical part of a presurgical evaluationevaluation
Focus of study is to Focus of study is to correlate EEG findings correlate EEG findings with lesion on MRIwith lesion on MRI
Preoperative evaluation of surgical Preoperative evaluation of surgical candidatescandidates
Usually for Usually for intractableintractable temporal or extra-temporal temporal or extra-temporal epilepsyepilepsy
Can be performed with Can be performed with sphenoidal or foramen sphenoidal or foramen ovale electrodesovale electrodes
Subdural grid placements Subdural grid placements can be used in conjunction can be used in conjunction with a neurosurgeonwith a neurosurgeon
Evaluation of patient in coma as Evaluation of patient in coma as treatments for status epilepticustreatments for status epilepticus
Status epilepticusStatus epilepticus
Patients often demonstate continued Patients often demonstate continued subclinicalsubclinical seizure discharges after the seizure discharges after the clinical behaviors have ceaseclinical behaviors have cease
EEG monitoring is necessary in all EEG monitoring is necessary in all patients in drug induced coma as a patients in drug induced coma as a treatment for status epilepticustreatment for status epilepticus
• Need to document burst suppression pattern Need to document burst suppression pattern induced by medsinduced by meds
Long term EEG monitoring: Long term EEG monitoring: Other usesOther uses
Intraoperatively:Intraoperatively: Functional stimulation Functional stimulation
during resectionsduring resections Intraoperative surface Intraoperative surface
EEG monitoringEEG monitoring• carotid endarterectomycarotid endarterectomy
Other monitoring modalities:Other monitoring modalities:
Digital ambulatory Digital ambulatory monitoringmonitoring Patient wears a digital Patient wears a digital
EEG recorder homeEEG recorder home Records 24 hours of Records 24 hours of
digital EEGdigital EEG Patient records Patient records
symptoms in a diarysymptoms in a diary
In Summary:In Summary:Video EEG monitoringVideo EEG monitoring
Captured 50-96% of epileptic and Captured 50-96% of epileptic and nonepileptic events (Legatt AD and nonepileptic events (Legatt AD and Ebersole JS, 1998).Ebersole JS, 1998).
Established a diagnosis in 88-95% Established a diagnosis in 88-95% (Legatt AD and Ebersole JS, 1998).(Legatt AD and Ebersole JS, 1998).
Improved outcome in 30-74% of patients Improved outcome in 30-74% of patients (Legatt AD and Ebersole JS, 1998).(Legatt AD and Ebersole JS, 1998).
St. Vincent HospitalSt. Vincent Hospital
Routine EEG – outpatient or inpatientRoutine EEG – outpatient or inpatient Ambulatory EEG – 24 hour outpatient studyAmbulatory EEG – 24 hour outpatient study Video EEG monitoringVideo EEG monitoring
3 adult rooms (hardwired)3 adult rooms (hardwired) 1 portable unit (adult or pediatric)1 portable unit (adult or pediatric) 1 ICU monitoring room1 ICU monitoring room
A neurologistA neurologist