Division of Neurology,
Bambino Gesù Children's Hospital, Rome,
Italy.
Abstract
Yawning is an involuntary sequence of mouth
opening, deep inspiration, brief apnea, and slow
expiration. Few cases of yawning as a clinical
sign of epileptic seizures, ictally or
postictally, have been reported. We report the
video/EEG documentation of yawning as an ictal
sign in a 31-year-old patient affected by
drug-resistant focal epilepsy symptomatic of
bilateral perisylvian polymicrogyria. Since the
age of 10 she has had seizures characterized by
yawning, staring, and eye blinking. Bilateral
rhythmic frontotemporal spikes and waves
characterized her EEG.
We reviewed all reported cases and compared
clinical and EEG features. We believe that
yawning as part of an epileptic seizure might be
considered a rare automatic behavior, like other
automatisms frequently reported in epileptic
seizures. Automatisms are more frequently
described in patients with temporal lobe
epilepsy, and involvement of the temporal lobe
in most of the published cases may have led to
this explanation. It is possible that yawning
within epileptic seizures could be considered
activation of distinct symptomatogenic cortex
rather than a release phenomenon. This rare
ictal manifestation should be recognized as
epileptic to avoid misdiagnosis and treatment
failure.
(A) Ictal video/EEG recording during a
typical episode of yawning (Video 1, Sequence
2&emdash;see Appendix). The EEG of the episode
shows low- to medium-voltage fast activity over
bilateral central areas lasting a few seconds,
followed by rhythmic spikes and polyspikes
involving bilateral central and frontal areas
during which the patient yawns. Multiple
artifacts related to mouth movement and tongue
protrusion are also evident. A prolonged
subclinical sequence of spike-and wave complexes
is evident over frontal and central areas after
the artifacts. Arrows indicate the correlation
with the snapshot of the video.
(B) Snapshot of the video showing ictal
yawning and eyelid myoclonia.
1. Introduction
Yawning is a physiological event that occurs
in both animals and humans. In mammals it is an
involuntary sequence of mouth opening, deep
inspiration, brief apnea, and slow expiration .
The physiological mechanism underlying yawning
remains unknown, but various brain structures
are related to this event.
Several physiological events can lead to
yawning such as drowsiness, sleepiness, and
emotional states; also, yawning may be induced
by pathological conditions such as stroke,
encephalitis, Parkinson's disease, migraine,
frontal lobe and brainstem tumors, and
amyotrophic lateral sclerosis. Numerous
neurotransmitters, neuropeptides, and hormones
are implicated in the control of yawning.
Neuroendocrine substances such as dopamine,
acetylcholine, serotonin, nitric oxide,
noradrenaline, oxytocin, and steroid hormones
have a facilitatory effect; opioid peptides and
GABA have an inhibitory effect. There is
evidence of contagious yawning, which occurs in
40-60% of adult humans and is probably related
to mirror-neuron system activity. Despite this
evidence, the role and physiology of yawning are
not clear.
Few cases of yawning as a clinical sign of
epileptic seizures have been reported: the
majority of patients described had symptomatic
temporal lobe epilepsy, and yawning was reported
as an ictal or postictal sign.
Our aim was to contribute to the
understanding of the clinical semiology and
neurophysiological features of patients affected
by symptomatic focal epilepsy with seizures
characterized by yawning in association with
staring and eye blinking. Moreover, we reviewed
all reported cases and compared their clinical
and EEG features.
2. Case report
This 31-year-old woman was born at term
after an uneventful pregnancy. She was the first
child of healthy nonconsanguineous parents.
Perinatal moderate hypoxia and bilateral hip
dislocation were reported. No family history of
epilepsy or other neurological disorders was
reported. Moderate psychomotor retardation was
evident since the first year of life.
At the age of 16 months she started to have
focal seizures characterized by psychomotor
arrest and left- or right-sided head and eye
deviation, sometimes followed by tonic posturing
of the upper limbs. Several EEGs showed
bilateral frontal and frontal and temporal
epileptiform abnormalities. Seizure frequency
was almost daily soon after onset. The patient
was treated with carbamazepine (30 mg/kg/day),
which was ineffective. Polytherapy with
carbamazepine and clobazam (1 mg/kg/day) led to
a reduction in seizure frequency. Brain MRI
revealed bilateral perisylvian polymicrogyria.
The karyotype was normal. Over the following
years, seizure frequency varied from weekly to
monthly.
At the age of 10 years, seizure semiology
changed, and bilateral eye blinking, yawning,
and staring were observed. During puberty she
had started to experience atypical absences,
which were successfully treated with valproate
(30 mg/kg/day). At the age of 18, video/ EEG
monitoring captured several seizures showing
varied, intermingled bilateral eye blinking and
yawning; yawning was usually the first sign
after the onset of the electrical discharge.
Loss of consciousness was difficult to ascertain
because of the underlying cognitive impairment.
Bilateral rhythmic central and frontal spikes
and waves characterized the EEG, at times
preceded by low-voltage rhythmic diffuse spike
discharges. Lamotrigine (5 mg/kg/day) was added
with a slight improvement in seizure
frequency.
During follow-up she has continued to the
present with almost monthly focal seizures, most
of them characterized by psychomotor arrest and
yawning of brief duration with an EEG similar to
that already described.
3. Discussion
Yawning has rarely been reported in
association with epilepsy. The anatomical
network involved in yawning is not clear, but
the reticular formation and brainstem seem to be
involved. The paraventricular nucleus of
hypothalamus, through projections to the
hippocampus, pons, and medulla oblongata, may
also be involved in the generation of yawning.
Penfield and jasper were the first to describe
yawning as part of an epileptic seizure in two
patients affected by symptomatic temporal lobe
epilepsy with autonomic seizures and cryptogenic
epilepsy with mainly autonomic seizures; in both
cases, yawning was reported to be strictly
related to seizures.
Ten other cases have been published since
those first two cases. Table 1 summarizes the
main clinical findings in all cases reported.
Most patients had temporal lobe epilepsy (9/12);
for two patients, type of epilepsy was not
specified, and the one patient remaining had
infantile spasms symptomatic of a brain
malformation. The seizure semiology of most of
these patients was characterized by staring,
sometimes preceded by aura and followed by oral
or motor automatisms, but motor phenomena were
also reported. Our case presented with episodes
of staring associated with bilateral eye
blinking. In 50% of reported patients, yawning
occurred as the main part of the seizure, and in
the other half, yawning occurred postictally but
was strictly related to the seizure. In all
seizures recorded for our patient, yawning was
one of the first signs of the seizure. Etiology
was symptomatic in 8 of 12 patients reported;
tumor and malformations were the most frequently
described lesions. All but two cases so far had
a focal lesion, in contrast to our patient who
had a bilateral malformation of cortical
development. When reported, ictal EEG revealed a
focal discharge or diffuse attenuation. It has
also been postulated that in temporal lobe
epilepsy, yawning may have lateralizing value
(for the nondominant hemisphere); this should be
kept in mind during presurgical evaluation of
patients with drug-resistant focal
epilepsy.
Outcome was good in most of cases, and
either pharmacological treatment or surgery led
to a complete remission. Our patient, however,
had drug-resistant epilepsy, and seizures
slightly decreased only on polytherapy.
4. References
[1] Walusinski
O, Deputte BL. The phylogeny, ethology and
nosology of yawning. Rev Neurol
2004;160:1011&endash;21.
[14] Yankovsky
AE, Andermann F, Dubeau F. Post-ictal
forceful yawning in a patient with nondominant
hemisphere epilepsy. Epileptic Disord
2006;8:65&endash;9.
[15] Kuba
R, Musilová K, Brázdil M, Rektor
I. Peri-ictal yawning lateralizes the
seizure onset zone to the nondominant hemisphere
in patients with temporal lobe epilepsy.
Epilepsy Behav 2010;19:311&endash;4.
-Specchio
N, Carotenuto A et al. Ictal yawning in a
patient with drug-resistant focal epilepsy:
Video/EEG documentation and review of literature
reports.Epilepsy Behav
2011
