-
- Insular
and caudate lesions release
- abnormal
yawning in stroke patients
- Krestel H, Weisstanner C, Hess CW, Bassetti
CL, Nirkko A, Wiest R.
-
- Yawning
and Stroke Bâillements
et AVC
- Pathological yawning (PY) is a compulsive,
frequent, repetetive yawning triggered by a
specific reason besides fatigue or boredom. It
may be related to iatrogenic, neurologic,
psychiatric, gastrointestinal or metabolic
disorders. PY could also be seen in the course
of ischemic stroke. The authors aimed to
determine whether PY is a prognostic marker of
middle cerebral artery (MCA) stroke and evaluate
its relationship with the infarct location.
-
- They examined 161 patients with acute middle
cerebral artery stroke who were consecutively
admitted to emergency department. Demographic
information, stroke risk factors, stroke type
according to Trial of ORG 10172 in Acute Stroke
Treatment (TOAST) classification, blood oxygen
saturation, body temperature, blood pressure,
heart rate, glucose levels, daytime of stroke
onset, National Institutes of Health Stroke
Scale (NIHSS, at admission and 24 h), modified
Rankin Scale (mRS, at 3 m) and infarct locations
were documented. PY was defined as ³3 yawns/15
min. All patients were observed for 6 hours to
detect PY. NIHSS>10 was determined as severe
stroke. The correlation between the presence of
PY and stroke severity, infarct location and the
short and long term outcomes of the patients
were evaluated.
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- Sixty-nine (42.9%) patients had PY and 112
(69.6%) patients had cortical infarcts. Insular
and opercular infarcts were detected in 65
(40.4%) and 54 (33.5%) patients respectively. PY
was more frequently observed in patients with
cortical, insular and opercular infarcts
(p<0,05). PY was related to higher NIHSS
scores. Patients with severe stroke (NIHSS³10)
presented with more PY than mild to moderate
strokes (p<0.05).
-
Le bâillement pathologique (BP) est un
bâillement compulsif, fréquent et
répétitif, déclenché
par une raison spécifique, autre que la
fatigue ou l'ennui. Il peut être
lié à des causes
iatrogènes, neurologiques,
psychiatriques, gastro-intestinaux ou
métaboliques.Un BP peut également
être observée au cours d'un AVC
ischémique.
-
- Les auteurs ont cherché à
déterminer si BP est un marqueur
pronostique de l'AVC de l'artère
cérébrale moyenne (MCA ou sylvien)
et à évaluer sa relation avec
l'emplacement de l'infarctus. Dans les accidents
vasculaires cérébraux, le BP est
correlé à la gravité de
l'AVC, à la présence d'une
atteinte corticale, aux infarctus insulaire et
operculaire. Cependant, aucune association n'a
été trouvée concernant
l'état fonctionnel à long terme et
la mortalité.
-
- PY in MCA stroke is associated with stroke
severity, presence of cortical involvement,
insular and opercular infarcts. However no
association was found regarding long term
outcome and mortality.
-
- Stroke is a common neurological disease
which is the major cause of disability and
mortality in both genders and has an
accelerating frequency due to the increase in
life expectancy in adult age group. (1, 2) A
variety of factors influence the outcome of
stroke including age, gender, stroke severity,
early rehabilitation, stroke etiology, infarct
location, rehabilitation, cognitive decline,
aphasia, depression and comorbid diseases. (3)
Being able to predict the prognosis of stroke
makes length of stay in the hospital or long-
term costs manageable and may reduce the
economic burden of stroke. Studies providing and
comparing prognosis, survival and recurrence
data in stroke allows clinicians to identify
high-risk patients for stroke recurrence and
stroke-related death, researchers to plan
clinical trials to develop new strategies, and
provide public health policy-makers with a
clearer picture of the social impact of ischemic
stroke.
-
- Yawning is a very common stereotyped motor
behavior which is physiologically observed in
humans, other mammals and numerous animal
species. (4, 5) Healthy humans may yawn 0-28/day
and this frequency of physiological yawning may
vary according to the age, circadian rhythm,
arousal, decreased attention, boredom, fatigue,
hunger, satiety, before and after sleep
episodes. (6, 7) Former studies revealed that,
paraventricular nucleus of the hypothalamus,
hypocampus, reticular activating system in the
brainstem, cervical spinal cord (phrenic nerve
C1&endash;4), intercostal muscles, oxytocin,
acetylcholine, dopamine, glutamate, serotonin,
GABA, adrenergics, ACTH, and ·MSH are
involved in the occurrence and the mediation of
yawning. (6-8) Cortical involvement of yawning
has been defined by recent studies but not fully
demonstrated yet. (5, 7) Frequent, repetetive
and compulsive yawning episodes are termed as
excessive, abnormal or pathological.
-
- Besides the physiological factors such as
fatigue, boredom or contagion, pathological
yawning (PY) is found to be triggered by various
cases, iatrogenic causes, and several metabolic,
gastrointestinal, psychiatric, or neurological
diseases. (9-12)
- PY has been reported in numerous
neurological conditions including parkinsonism,
Parkinson's disease, progressive supranuclear
palsy, Huntington disease, myasthenia gravis,
bulbar amyotrophic lateral sclerosis, multiple
sclerosis, neuromyelitis optica spectrum
disorders, migraine aura, vasovagal syncope,
narcolepsy, brain tumor, encephalitis,
intracranial hypertension, stroke, Chiari
malformation type I, epilepsy, stress and
anxiety disorders. (6, 9-25)
- Although PY in brainstem and anterior
circulation (AC) ischemic stroke has been
previously reported in the literature; to date,
the exact mechanism of cortical network remains
to be established by functional neuroimaging
studies. Some recent studies concluded that
ischemic lesions of the posterior insula and
caudate nucleus induces PY. Still there is no
sufficient clinical data in humans regarding PY
in AC stroke and no data regarding the frequency
or prognostic effect of PY on long-term
prognosis and mortality rates of middle cerebral
artery (MCA) strokes.
-
- This observational study investigates
whether PY affects the clinical outcome and
mortality of the patients with acute MCA stroke.
We hypothesised that certain infarct locations
in the AC system may facilitate PY and the
presence of PY may be considered as a prognostic
factor of MCA strokes. Among our cohort of 161
patients, PY was observed in 69 (42.9%) patients
and likely to occur in patients with higher
NIHSS scores. The equal distribution of gender
is a strong aspect of our study. We found PY to
be related with cortical involvement, insular
and opercular infarcts. Our study revealed that,
PY is a common phenomenon among patients with
MCA stroke and seems to be associated with
stroke severity. However, no relationship was
found regarding its effect on long term outcome
or mortality rates of the patients.
-
- The evidence of former case reports and
studies suggests that PY occurs frequently in
the course of many neurological diseases. (6,
9-25) A limited number studies have been
reported PY in acute ischemic stroke. (9, 23,
24) Bauer et al. stated that, the patients with
locked-in syndrome can elicit yawning movements
involuntarily despite the total paralysis of the
volunteer bulbar muscles. (27) Cattaneo et al.
published a case report of two patients with
brainstem stroke who were presented with PY. (9)
To date, only 2 studies have provided data
concerning PY in AC stroke. The pivot study of
Singer et al. revealed that PY can be a sign of
AC lesions. They observed PY in 7 patients with
AC strokes in MCA territory and hypothesized
that PY occurs due to supratentorial lesions
releasing the hypothalamic PVN from neocortical
control mechanisms and increasing activity of
hippocampus and periamygdalar regions. (24) A
more recent study of Krestel et al. investigated
PY in 10 patients with acute AC.
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- Infarct regions and volumes of the patients
were evaluated using MRI lesion maps, diffusion
weighted (DWI) and apparent diffusion
coefficient (ADC) images. Intensity of the
infarcts were found to be correlated with the
period of abnormal yawning They proposed that
insular and caudate nucleus infarcts are
responsible for PY. (25) The use of dopaminergic
D2 agonists, imipramine, selective serotonin
reuptake inhibitor (SSRI) agents, morphine
withdrawal, valproate overdose and oestrogen
substitution may induce PY. Anesthetic agents
are leading drowsiness and loss of
consciousness. (28) None of our patients were
using these agents. Intravenous thrombolytic
therapy has a positive impact on prognosis.
However, we found no significant relationship
between the patients who received thrombolytic
therapy and the occurrence of PY.
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- It has been noted that PY is primarily
triggered by low vigilance. However, PY can be
seen even there is no change in consciousness
level during stroke attacks. This may be as a
result of the increased intracranial pressure
secondary to stroke or the damage of the
particular cortico-subcortical circuits and the
disruption of theconnections between the
reticular formation that regulates alertness in
the brain stem. As the clinical severity of
stroke increases, PY is observed more
frequently.
-
- Krestel et al. found a significant
correlation between the period of PY and stroke
severity. (25) Factors such as low vigilance,
increased brain temperature, intracranial
hypertension, deterioration of homeostasis and
damage of more neuroanatomical structures
including cortico-subcortical circuits may be
the possible causes of PY. (5-7)
- This study has several limitations. First of
all, during observation period we could not
video-record the patients. Thus, the duration or
the distinctive features of yawning attacks
could not be measured quantitatively. Moreover,
despite the cut-off yawning count for PY (³3/15
min) was determined after two previous studies
(24, 25), physiological yawning may also occur
at the same frequency. And finally sleepiness
scale tests could not be performed to the
aphasic or clinically severe patients. This
situation has led us insufficient data regarding
increased sleepiness or drowsiness of the
patients.
- Further studies measuring the
neurotransmitter and neurohormone levels
released during PY attacks in acute stroke or
using improved neuroradiological tools such as
tractography are required to discover the exact
pathophysiological mechanism and neural pathways
responsible for PY. The causative factors that
triggers PY in acute stroke, involving cortical
brain areas and clinical significance of PY
still remains to be clarified.
-
- To the best of our knowledge, the present
study is the first one analyzing the clinical
and radiologic findings of PY in acute MCA
stroke with larger human cohort including
findings regarding long- term outcome and
mortality rates of the patients with PY.
Consistent with the existing evidence, our study
revealed that cortical involvement, opercular
and insular infarcts trigger PY. Supporting
statistically, we established the clinical
significance of PY and could evaluate its
prognostic role in MCA stroke. Notwithstanding
its connection with the clinical severity, PY
reveals no significant predictive value for
clinical outcome of patients with MCA stroke.
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