Transcript Video-EEG Monitoring in Childhood Epilepsy

Video-EEG Monitoring in
Childhood Epilepsy
M. Mohammadi MD
Professor of Pediatric
Neurology (TUMS)
Former Fellow, Clinical Paediatric
Neurophysiology, University College of
London, GOS Hospital, London, UK.
November 2006
Major Queries
Advantages of the
Outpatient EEG Study?
• The outpatient "routine" EEG is the most
commonly performed diagnostic procedure
in the individual who has a suspected
seizure disorder.
• For most patients, the routine EEG is
sufficient for physicians to classify seizure
types and initiate medical therapy.
Advantages of the
Outpatient EEG Study?
• The neurologic history and examination
and routine EEG indicate the probable
seizure diagnosis in most patients.
• The outpatient sleeping and waking EEG
study usually identifies interictal EEG
activity, in patients with seizure disorders.
• Interictal epileptiform activity may be
satisfactory in many instances to classify
the seizure types.
Limitations of the
Outpatient EEG Study?
• The brief duration of the EEG
recordings may fail to identify
epileptiform activity.
• The routine EEG may be repetitively
normal and identify no epileptiform
discharges.
Limitations of the
Outpatient EEG Study?
• EEG may record nonspecific and
nonepileptiform findings that may incorrectly
suggest the diagnosis of epilepsy.
• Interictal EEG alone may lead to errors in
diagnostic classification that result in ineffective
treatment strategies.
• The interictal EEG pattern also may be an
unreliable indicator of the classification of
seizure type.
TYPES
• Outpatient vs. Inpatient
Settings
• Ambulatory vs. Nonambulatory EEG monitoring
• Analog vs. computer
assisted digital video EEG
monitoring
IMPLICATIONS
 Diagnosis of a seizure disorder
 Classification of seizure types
 Evaluation of precipitating
factors
 Quantification of seizures
 Surgical localization
Does the Patient Have
Epilepsy?
 Approximately 20% of patients who are referred
to comprehensive epilepsy programs because of
medically refractory "seizures" do not have
epilepsy.
 Physiological and psychological disorders may
cause diagnostic confusion with epilepsy and
result in patients being inappropriately treated
with antiepileptic medications.
 A normal scalp-recorded EEG during and after a
"seizure" in an unresponsive patient virtually
excludes an epileptic clinical event.
Nonepileptic Phenomena Confused
with Epilepsy
 Autonomic Disorders
 Cardiac Arrhythmias
 Cerebrovascular
Disease
 Drug Toxicity
 Metabolic Disorders
 Migraine
 Orthostatic
Hypotension
 Valvular Heart
Disease
 Vasovagal Syncope
 Vestibular Disorders
 Shuddering attacks
 Breath Holding Spells
 Sleep Disorders
 Day Dreaming
 GER
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Nonepileptic Psychologic
Phenomena Confused with
Epilepsy
Anxiety
Depression
Panic attacks
Psychogenic seizures
Psychosis
Somatoform disorders
Rage attacks
What is the Seizure Type?
• In one study, the diagnostic classification was
altered in 19 (47.5%) of 40 patients by inpatient
video-EEG monitoring.
• Studies also disclosed previously unrecognized
seizures in 20% of patients monitored.
• Improved seizure control can occur in 60% to
70% of patients as a result of videoEEG
monitoring.
• Prolonged EEG recordings are clearly superior
to the routine EEG in detecting seizures (50%70% with long-term monitoring compared with
2.5%-7% with routine EEG studies).
Is the Patient a Candidate
for Epilepsy Surgery?
• The most effective treatment of intractable
partial epilepsy is resection of the epileptic brain
tissue.
• Of the nearly 800,000 patients with partial
epilepsy in the United States, 45% have
medically refractory seizure disorders.
• The most commonly performed and most
effective procedure for treating intractable
epilepsy is an anterior temporal lobectomy, after
which nearly 60% of patients are seizure-free
and 90% are substantially improved.
Is the Patient a Candidate
for Epilepsy Surgery?
• The surgically remediable epileptic
syndromes include medial temporal
lobe epilepsy and partial epilepsy
related to lesional pathology, eg, a
primary brain tumor.
• Approximately 80% of patients with
medial temporal lobe epilepsy
associated with mesial temporal
sclerosis have an excellent outcome.
Is the Patient a Candidate
for Epilepsy Surgery?
• Confirmation of the localization of the
epileptogenic area is critical to
identifying appropriate candidates.
• An inability to localize the
epileptogenic area sufficiently with
noninvasive monitoring is an indication
for long-term intracranial EEG
monitoring, eg, subdural grid or
implanted depth electrodes.
Limitations of Video-EEG
Monitoring?
• Needs Special Training
– Technicians
– Interpretators
– Maintaining Personnel
• Logistically Difficult (Wi Fi Cordless
Technology)
• Needs Patients’ Cooperation
• Needs Interdisciplinary Approach