Clinical Journal of Gastroenterology
https://doi.org/10.1007/s12328-018-0916-7

CASE REPORT

Acute hemiparesis and status epilepticus following endoscopic
esophageal balloon dilation: is it really a stroke?
Nicholas Di Mascio1,4

· Padraic MacMathuna2 · Sean Murphy1 · Eoin Carl Kavanagh3

Received: 23 May 2018 / Accepted: 16 October 2018
© Japanese Society of Gastroenterology 2018

Abstract
A 68-year-old gentleman was referred for elective upper gastrointestinal endoscopy on a background of dysphagia and
esophageal candidiasis. A benign peptic stricture was noted, managed with balloon dilation without apparent immediate
complication. At completion, however, the patient became confused and agitated, with no improvement despite the reversal
of sedation. Two hours later, with all investigations for suspected complications including perforation, negative, he developed
acute left-sided hemiparesis. Urgent computed tomography brain and angiogram were both normal. A diagnosis of acute
ischemic stroke was made, and the patient was thrombolysed in the Intensive Care Unit. No improvement of the stroke was
observed. Seven hours later, the patient developed generalized tonic-clonic seizures that required phenytoin infusion and
subsequent intubation and ventilation. The following morning, magnetic resonance imaging brain did not reveal features
of a stroke, but instead diffuse cortical and white matter edema in the right frontal lobe, consistent with atypical, unilateral
Posterior Reversible Encephalopathy Syndrome (PRES). Signs and symptoms resolved rapidly over the course of several
days, and after one month the patient made a complete clinical and radiological recovery. To our knowledge, this is the only
case of PRES to arise in the setting of endoscopy and esophageal dilation.
Keywords Endoscopy · Balloon dilation · Esophageal stricture · Stroke · Posterior Reversible Encephalopathy Syndrome
(PRES)

Introduction
Posterior reversible encephalopathy syndrome (PRES), is a
clinical-radiographic syndrome of heterogenous etiologies,
characterized by acute neurological symptoms arising as a
result of vasogenic brain edema. Though rare, it is increasingly recognized, largely due to the increased availability of magnetic resonance imaging (MRI) [1]. PRES can
arise in a variety of contexts, though is most often associated with hypertension, pre-eclampsia/eclampsia, renal

* Nicholas Di Mascio
nickdm91@hotmail.com
1

Mater Misericordiae University Hospital, Dublin, Ireland

2

Department of Gastroenterology, Mater Misericordiae
University Hospital, Dublin, Ireland

3

Department of Radiology, Mater Misericordiae University
Hospital, Dublin, Ireland

4

Medical Teaching Unit, St John of God Hospital, 12 Salvado
Road, Subiaco, WA 6008, Australia

disease, auto-immune conditions, sepsis, organ transplant,
malignancy, and use of cytotoxic/immunosuppressive drug
therapies [2]. The most common presenting features are
encephalopathy, seizures, headache, visual disturbance, focal
neurological deficit, and status epilepticus [1]. Though the
exact pathophysiology is not fully understood, endothelial
dysfunction with subsequent breakdown of the blood–brain
barrier (BBB) is known to play a key role [1]. The radiographic features are classically described as bilateral subcortical and cortical hyperintensities seen predominantly in
the parieto-occipital regions on fluid-attenuated inversion
recovery (FLAIR) MRI sequences [3]. While there is no
specific treatment for PRES, complete resolution both clinically and radiographically is seen in up to 90% when the
precipitating cause is treated or eliminated [1]. In rare cases,
however, cerebral hemorrhage or ischemia may cause irreversible neurological damage or even death [4].
We present a highly unusual case of PRES that occurred
following balloon dilation of a benign esophageal stricture.

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Case description
A 68-year-old gentleman walked into the gastrointestinal
(GI) day unit for an elective endoscopic balloon dilation,
on a background history of recent dysphagia. His past
medical history was notable for Crohns disease (quiescent
for over 15 years), recurrent angio-edema, and chronic
back pain. His regular medications included lansoprazole,
gabapentin, and fexofenadine.
Standard sedation with intravenous (IV) midazolam
5 mg was used, and a benign esophageal peptic stricture
was noted within a hiatus hernia (Fig. 1). The stomach and
duodenum were both normal, and the esophageal stricture
was not believed to have been Crohns related. The stricture was dilated using a through the scope (TTS) balloon,
inflated to 20 mm diameter without apparent immediate
complication. At completion, however, the patient’s level
of consciousness decreased significantly. Sedation was
promptly reversed with flumazenil but to no significant
avail. Blood pressure (BP) was elevated at 168/80 mmHg,
with other vital signs within normal limits. Despite supportive measures, the patient became distressed with
fluctuating levels of consciousness, and shortly after the
procedure developed new neck pain. Esophageal perforation was promptly ruled out both clinically and on chest
X-ray. Two hours later, the patient was noted to have a new
dense left hemiparesis, left facial droop and severe left
hemineglect. Urgent computed tomography (CT) brain and
angiography showed no evidence of hemorrhage, intracranial lesion, arterial dissection or air embolism. Laboratory
investigations at this time were also unremarkable. A clinical diagnosis of acute ischemic stroke was made by the oncall Vascular Neurologist, and the patient was transferred
to the intensive care unit (ICU) for thrombolysis.

Fig. 1  Esophageal stricture
within a hiatus hernia noted on
endoscopy

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Seven hours post-thrombolysis the patient developed
two tonic-clonic seizures; the first focal involving the left
upper limb, and the second generalized. With no resolution
following IV midazolam and loading doses of phenytoin,
the patient eventually required intubation and ventilation
with propofol for sedation. A second CT brain was again
unremarkable.
Later that morning the patient was sent for MRI brain.
To our surprise, the MRI findings were not consistent with
cerebral ischemia, but instead revealed diffuse cortical
and white matter edema throughout the right hemisphere
(Fig. 2A). There was no hemorrhage, mass/mass effect,
restricted diffusion or reduction in ADC signal. The patient
was extubated later that day and his condition improved over
the next 24–36 h. Repeat MRI brain two days post-procedure
showed more extensive white matter edema (Fig. 2B), and
the radiology opinion was that the imaging features were
“highly unusual” and “may relate to Posterior Reversible
Encephalopathy Syndrome”. This view was supported by
Neurology, who felt that findings were consistent with atypical unilateral PRES.
The patient’s overall condition and neurological signs
quickly improved, and he was discharged home on day 14
to pursue ongoing physiotherapy and occupational therapy
in the community. MRI brain at ten days showed substantial improvement in the subcortical white matter edema
(Fig. 2c), and by four weeks, both clinical and radiological
signs had completely resolved (Fig. 2d).

Discussion
To our knowledge, no other case of PRES has occurred in
the context of upper GI endoscopy or esophageal balloon
dilation. Typically, complications of endoscopy relate either

Clinical Journal of Gastroenterology
Fig. 2  a Axial FLAIR MRI
day 0, Diffuse cortical and
white matter edema of right
frontal lobe (arrows). b Axial
FLAIR MRI day 2, More
extensive white matter edema
than when compared to prior
study (arrows). c Axial FLAIR
day 12, Cortical edema in right
frontal lobe almost completely
resolved. Some persistent subcortical edema (arrows). d Axial
FLAIR MRI day 61, Complete
interval resolution of both cortical and white matter edema

to sedation, endoscopy itself, or any therapeutic intervention performed. Sedation-related complications are usually cardiopulmonary and include respiratory depression,
hypoxemia, hypotension, and aspiration [5]. Hypotension
can result not only from the vasodilatory effects of sedative
medications but also from vagal stimulation and subsequent
bradycardia [6]. Conversely, hypertension is also commonly
seen, usually in response to anxiety or discomfort caused
by the procedure itself [6]. Thus, a certain amount of blood
pressure flux is common. Complications relating specifically
to esophageal stricture balloon dilation include perforation,
hemorrhage and bacteremia [6]. Our biggest concern at time
of procedure was esophageal perforation. Although very
rare, the mortality rate is high at 2–36% [7]. Our suspicion
for perforation was soon allayed, however, by a lack of other
correlating clinical signs and radiographic findings. Events
then became even more alarming when the patient developed sudden, dense left hemiparesis. In the context of neck

pain, carotid/vertebral artery dissection was considered.
This, however, was also ruled out following a normal CT
angiogram and brain. With all clinical data pointing toward
an acute ischemic stroke, the patient was then thrombolysed
under the supervision of a Consultant Neurologist. Having
started as an elective day-case procedure, for the patient to
ultimately arrive at ICU requiring intubation and ventilation was, in our experience, unprecedented. It was only after
utilization of MRI that a diagnosis of PRES began to materialize, which was further reinforced by the patient’s rapid
recovery.
With improved availability of MRI, PRES is becoming
increasingly recognized in a broad variety of clinical scenarios. It is important to maintain a high clinical suspicion of
PRES when faced with acute/subacute neurological symptoms that appear out of context or otherwise unexplained.
While encephalopathy and seizure are the most common
presenting features of PRES [1], atypical presentations

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Clinical Journal of Gastroenterology

such as this are increasingly reported [8]. Focal neurological deficits are seen in up to 15% [1], however, there are
exceptionally few other cases where PRES has mimicked an
acute stroke so convincingly. Indeed, we can find no other
case where the patient was ultimately thrombolysed, such
was clinical impression of stroke so incontrovertible. Other
differentials worthy of mention are cerebral air embolism
and intra-cerebral hemorrhage. With only five published
cases in the literature, cerebral air embolism is considered
an exceptionally rare but recognized complication of endoscopic esophageal dilation. Likewise, there is only one case
in the literature which describes intra-cerebral hemorrhage
following endoscopy for removal of a benign gastric polyp.
In this case, the authors attribute the intra-cerebral hemorrhage to an acute transient rise in blood pressure, thought to
be secondary to the stress of the procedure, and/or systemic
absorption of adrenaline used in hemostasis. In our case,
however, no radiological evidence of either air embolism or
hemorrhage could be found on any of the imaging modalities used.
Why endoscopy or esophageal dilation should trigger
a unilateral PRES is not clear. PRES is thought to result
from endothelial dysfunction and is most often seen in the
settings of acute hypertension, systemic inflammatory processes, and cytotoxic drug use. There are two main theories
for the pathophysiological mechanisms of the condition.
The first, is that rapidly evolving or fluctuating BP levels
exceed the upper limits of cerebral autoregulation, resulting in breakdown of the BBB, cerebral hyperperfusion, and
vasogenic edema [1]. Moderate to severe hypertension is
present in 50–70% of cases at symptom onset, and active
reductions in BP are associated with clinical improvement in nearly all cases [9]. Our patient was indeed acutely
hypertensive during the procedure, with BP increasing from
126/76 mmHg (mean arterial pressure [MAP] of 93 mmHg)
at baseline to a peak of 168/101 mmHg (MAP 123 mmHg)
over the course of 10 min. This represents only a modest
increase in MAP, however, which itself would not be sufficient to exceed the normal autoregulatory capacity of
150–160 mmHg [9]. Another, more well supported theory
is that circulating cytokines, as part of a systemic inflammatory state, cause direct injury to the cerebral endothelium,
leading to increased vascular permeability and subsequent
edema [1]. These systemic processes are common to many
of the conditions now known to be associated with PRES,
and recent studies have shown approximately 50% of PRES
to be associated with an underlying autoimmune condition
[1, 2]. Although our patient was known to have Crohns disease, it is unlikely to have precipitated PRES in this instance,
as it had been dormant for over 15 years.
Finally, the strictly unilateral neuroimaging features
demonstrated by this case were highly atypical. Classically, PRES is diagnosed based on bilateral hyperintensities

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on FLAIR sequences in the parieto-occipital cortical and
subcortical areas [3]. Previously considered atypical, it is
now known that frontal lobe, temporal lobe, cerebellum,
basal ganglia, brain stem and deep white matter are often
involved [3]. It was not until 2007, however, that a study of
76 patients described a new unilateral variant, the incidence
of which it reported at 2.6% [3]. Purely unilateral PRES is
exceptionally rare. Some authors offer the explanation that
asymmetric findings may relate to differences in arterial
anatomy, pre-existing vascular disease, or regional hemispheric involvement in the underlying toxic process [10].

Conclusion
This is the only case of PRES, to our knowledge, to be precipitated by upper GI endoscopy/balloon dilation. While a
certain degree of blood pressure flux is to be expected during
these procedures, it would not be of the magnitude sufficient
to exceed normal cerebral autoregulatory mechanisms. Current evidence in the literature suggests that the hypertension/
hyperperfusion theory does not adequately explain PRES
[11], and this case is in keeping with that trend.
This case further adds to the growing list of precipitants
and manifestations of PRES. Thus, the possibility of PRES
should be considered when faced with acute neurological
symptoms such as altered mental status, seizures, headache,
visual disturbances and focal neurological deficits following
endoscopy. With increasing availability of MRI, its early use
should be prioritized in this context. With prompt diagnosis,
inappropriate therapies such as thrombolysis may potentially
be avoided.

Compliance with ethical standards
Conflict of interest Dr. Nicholas Di Mascio, Professor Padraic MacMathuna, Professor Sean Murphy, and Professor Eoin Carl Kavanagh
declare that they have no conflict of interest.
Human/animal rights All procedures followed have been performed in
accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.
Informed consents Informed consent was obtained from all patients
for being included in the study.

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