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Movement Arousals
Movement arousals occur in neonates with normal or
abnormal neurological examinations. They are characterized by single jerks
or briefly sustained postures during sleep (click
on clip, below).
They are associated with EEG stage changes or transient
flattening of the background activity (click
on clip, below).
The periods of EEG flattening may last for up to
one minute. These periods of flattening occur more frequently during the
first transition from active to quiet sleep and may be bilateral or unilateral.
It is important not to mistake this electroencephalographic pattern with
those that occur during some electroencephalographic seizures. The interictal
electroencephalographic background activity may or may not be normal.
No significant changes in cardiac rate occur. They require no treatment.
Marcus Gunn
phenomenon
Marcus
Gunn phenomenon consists of retraction of the upper lid on opening the
jaw (click on clip below). This phenomenon when repetitive and unilateral
(as it usually is) may resemble a partial seizure. The clues to the diagnosis
of Marcus Gunn phenomenon are that the movements only occurs during feeding
or with repetitive mouth opening, and that ptosis of the eye lid is usually
present. The retraction of the lid is due to contraction of the levator
palpebrae. Contraction of the upper lid while opening the jaw occurs due
to aberrant innervation of the levator palpebrae by the external pterygoid
portion of the nucleus of cranial nerve V.
MALIGNANT PAROXYSMAL MOTOR EVENTS
Convulsions
Convulsions are paroxysmal motor events
characterized by increased motor activity that is believed to be a seizure
based on clinical observation or proven to be a seizure by its association
with an electroencephalographic seizure (click on
clip, below).
Convulsions may occur in neurologically normal or abnormal neonates.
A paroxysmal motor event is clinically considered a convulsion if it is
not triggered by stimulation or stops upon arousal and is characterized
by either: (1) focal tonic limb postures; (2) focal or multifocal clonic
limb movements; or (3) repetitive facial twitches
(click on clip, below).
Nevertheless, many of the events considered to be convulsions based on
these criteria are proven not to be so when studied by continuous EEG
recording and single photon emission computed tomography.
Any paroxysmal motor event with
increased motor activity associated with an electroencephalographic seizure
is a convulsion. Convulsions are associated with increased focal hemispheric
cerebral perfusion on single photon emission computed tomography.
Convulsions can be produced by disorders that require etiologic, antiepileptic
treatment, or both.
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