Second edition

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256 Other major syndromes
2007; Smaje et al. 1987): in such cases, if seizures cannot be
controlled, placement of a pacemaker may be required.
PETIT MAL SEIZURES
Petit mal seizures (Delgado-Escueta 1979; Penry et al. 1975;
Sadleir et al. 2006), also known as absence seizures, are
abrupt in onset and occur without an aura; they are very
brief, lasting of the order of 10 seconds, and generally consist
of an arrest of all activity accompanied by a blank stare:
the seizure ends as abruptly as it began, and there is no postictal
confusion or drowsiness. To the observer, it may
appear that the patient had a ‘blank’ spell or was merely
momentarily ‘out of it’ then ‘snapped to’. In some cases,
there may be some myoclonic fluttering of the eyelids and
occasionally some myoclonic jerks of the hands. Some
patients will also experience a partial loss of muscle tone:
the head may drop forwards, or the patient may slump
somewhat, but falls are unusual. Many patients will also
have some simple automatisms, such as lip-smacking,
chewing or fumbling, during the absence (Fuster et al. 1954;
Penry and Dreifuss 1969; So et al. 1984, Sadleir et al. 2006).
There may very rarely be other features, such as auditory or
visual hallucinations (Guinena and Taher 1955).
A variant of petit mal, known as ‘atypical absence’ may
be seen, most commonly in patients with mental retardation.
These atypical absences are of more gradual onset and
offset, tend to last longer overall, and may be associated
with prominent increased muscle tone (Holmes et al.
1987).
GRAND MAL SEIZURES
Grand mal seizures, often referred to as generalized
tonic–clonic seizures, may be preceded by an aura composed
of any of the symptoms or signs seen during simple
partial seizures, or may evolve out of a complex partial partial
seizure, a process known as secondary generalization.
As discussed below, under Etiology, it is critical to determine
whether or not grand mal seizures are preceded by an
aura or a complex partial seizure: grand mal seizures preceded
by such events may be assumed to have a ‘focal’
onset, that is to say to be due to a more or less localized
lesion, whereas those that lack such preceding events are
more likely to be occurring as part of one of the idiopathic
generalized epilepsies. Caution must be exercised here,
however, before deciding that no ‘focal’ features are present,
given that many patients who did, under video–EEG
monitoring, clearly have an aura, will be unable, after
recovering from the grand mal seizure, to recall the aura
(Schulz et al. 1995).
Typical grand mal seizures (Theodore et al. 1994) begin
with an abrupt loss of consciousness, often accompanied
by an inarticulate ‘cry’: immediately there is tonic activity
in all four extremities. After perhaps 15–20 seconds, the
tonic activity slowly fades to be gradually replaced by regular
clonic activity, which, in turn, may last anywhere from
30 seconds to 1.5 minutes. In some cases, there may be
variations, the tonic phase being preceded by a few clonic
jerks, or the tonic phase constituting the majority of the
seizure, with only a few clonic jerks trailing behind. During
the tonic activity, respirations cease and cyanosis may
appear. There is often incontinence of urine, and, during
the clonic phase, the tongue may be bitten. Upon cessation
of the seizure proper, most patients remain in a coma or
stupor for a matter of minutes. A delirium then supervenes,
with prominent confusion, lasting perhaps 15–30
minutes, after which most patients fall into a deep sleep.
ATONIC SEIZURES
Atonic seizures (Gambardella et al. 1994; Lipinski 1977;
Pazzaglia et al. 1985), also known as astatic seizures or
‘drop attacks’, occur without prodrome or aura and are
characterized by a sudden loss of motor tone. In most
cases, this atonus is generalized, and patients fall or slump
to the ground; occasionally, however, the lack of tone may
be focal, with, for example, only an abrupt drooping of the
head. The atonus itself generally lasts on the order of a few
seconds and may or may not be associated with a loss of
consciousness. After the restoration of normal tone, most
patients arise immediately, without any post-ictal confusion;
however, others may, for a minute or two, experience
a more or less profound degree of post-ictal confusion.
Atonic seizures generally occur only in patients who
have already suffered from complex partial or grand mal
seizures for many years (Gambardella et al. 1994; Lipinski
1977; Tinuper et al. 1998).
AMNESTIC SEIZURES
Amnestic seizures, also known as ‘pure epileptic amnesia’,
are characterized solely by the appearance of amnesia. As
such, they differ from complex partial seizures in that there
is no impairment of consciousness, no motionless stare,
and no automatic behavior. Typically, the amnesia itself is
primarily of the anterograde type but, in some cases, the
amnesia represents a combination of anterograde and retrograde
types. Rarely, the seizure will be characterized by
retrograde amnesia alone. Examples of each type follow.
Amnestic seizures of the anterograde type
These seizures are characterized by the abrupt onset of a
loss of short-term memory: patients are able to recall
events that occurred up to the onset of the seizure, and
behave normally during the seizure itself, but subsequent
to the termination of the seizure, they have no or only
spotty recall of the events that transpired concurrent with
the seizure itself; they generally last from minutes up to an
hour (Butler et al. 2007; Palmini et al. 1992). Palmini et al.
(1992) provide some interesting examples. In one case, a
waitress, during her seizure, ‘was able to compute a customer’s
bill accurately and to bring him a correct amount
of change’; later, upon recovery, ‘she then realized she had