The reason for monitoring is usually to identify and
localize the epileptogenic zone in order to evaluate the possibility of epilepsy
surgery.Other patients eligible for non-invasive intensive
monitoring are
- children with suspected pseudoseizures,
- children with frequent polymorphic seizures in order to
document the various seizure types and
- children with episodic behavioural disturbances and
abundant epileptiform activity in routine EEGs.
The purpose of intensive monitoring is to record clinical
seizures in order to eveluate any possible relationship with
electroencephalographic seizure patterns.
In children with very frequent clinical seizures only a
few hours of monitoring might be sufficient. In most cases the monitoring is
extended to several days, sometimes as long as two weeks. Reduction or
discontinuation of current antiepileptic drugs (AEDs) is often
necessary.
Presurgical evaluation:
First preoperative phase
(Phase I):
- Suffers the child from epileptic seizures that are
otherwise intractable, (especially refractory to AED treatment)?
Re-evaluation of diagnosis and seizure/syndrome classification,
therapeutic re-evaluation (review of drug treatment hithero given, including
compliance).
- Are there subjective handicap and social disability
and/or deteriorating development?
Evaluation of psychosocial
problems (covering aspects of cognitive and intellectual functioning, emotional
problems and reactions as well as interpersonal interaction and social
situations).
-
Is there any detectable etiology, i.e. organic brain
lesion and/or an area of dysfunction?
metabolic screening, CCT and high-resolution MRI
clinical neurological examination,
neuropsychological testing,
decreased blood flow
revealed by functional neuroimaging, e.g. interictal HMPAO-SPECT .
- Is there a localizable seizure-producing brain area?
Recording of a sufficient number of representative seizures,
with combined Video/EEG-monitoring from extracranial electrodes, including
sphenoidal ones. Increased blood flow (peri-)ictal HMPAO-SPECT.
- Are there sufficient mental health, resources,
tolerance?
evaluation by psychiatrist, psychologist and
other health personnel
A considerable number of children regarded as having
intractable epilepsy are not considered refractory sensu stricto and benefit
significantly from a systematic, comprehensive diagnostic and therapeutic
re-evaluation program which also takes into account psychosocial
aspects.
In the case that the results of all investigations of
phase I are congruent, the patient enters phase II
Second preoperative phase
(Phase II)
- Testing of hemispheric dominance for speech, memory,
musicality, initiation and control of motor and behavioural activities using
neuropsychological tests, perception tests and WADA tests (in children>8years
of age).
In the case that the identification and delineation of
the epileptogenic zone is not possible with surface EEG the pre-surgical work-up
is continued with (semi-)invasive recordings
Third preoperative phase
(Phase III)
intracranial recordings see Department of
Neurosurgery
Postoperative evaluation
phase
This phase starts at the epilepsy centre about two/three
days after the operation
EEG and clinical follow-up take place 1 week, 3 months,
6months, 1year, 2 years postoperatively, neuropsychological assessment at
6months and two years.
Drug regimen: AEDs are maintained for at least one year
and then discontinued, provided the child has remained completely
seizure-free.