Available Investigations and Clinical Indications
Routine
videoEEG
A
routine vEEG normally takes about 1 hour of which 20 minutes is
setting up,
20 minutes is recording and 20 minutes is cleaning
up. Reports are written after the
event and are usually sent to
the referring physician within two hours of the appointment.
The more specific
the question on the request
form, the more specific will be the report.
vEEG
has a broad range of indications including:
documentation of seizure by type, frequency, and severity
documentation of sub-clinical seizures
differentiating between 'blank' or 'daydreaming' episodes and true absence seizures
differential diagnosis of seizure vs. syncope
differential diagnosis of seizure vs. pseudo-seizure
differential diagnosis of seizure vs. behaviour manifestations
other unexplained alterations in conciousness
diagnosis and evaluation of sudden-onset dementias such as CJD
exclusion of seizure components in psychiatric disorders
evaluation of sleep disorders
evaluation of efficacy of anticonvulsant therapy over the long term
pre-screening prior to removal from anticonvulsants
A
vEEG can be of considerable
use where an unexplained alteration in awareness
has been
reported. Where a formal
diagnosis is yet to be made, a
vEEG within four
hours of such an
'event' may show post-ictal changes and/or
seizure activity
and provide some
diagnostic direction.
If an 'event' is
electrocephalic in origin, a
post-ictal disturbance will likely be recorded
and
so the EEG can
be particularly
useful to
discriminate between cephalic and functional
episodes. Please
note that if an on-demand EEG is required for this purpose, we may
be able to oblige at very short notice – please contact
us.
A
Sleep-deprived vEEG may be of value where an
initial EEG has shown
no abnormalities and there is a strong
clinical suspicion of a seizure disorder.
Due to the
increased risk of provoking seizures by sleep deprivation, a
routine
EEG is strongly advised as a first step.
Fully informed
consent is required prior to undertaking a Sleep-deprived vEEG
and
this should be obtained by referrer and confirmed on the request
form.