ARTICLE
Auteur(s) : Cigdem Ozkara1, Baris Metin1, Serdar
Kucukoglu2
1Department of Neurology, Cerrahpasa Medical
School
2Institute of Cardiology, University
of Istanbul, Turkey
Article reçu le 16 Juin 2009, accepté le 12 Octobre 2009
In clinical practice, the differential diagnosis between
epilepsy and syncope is not always easy. Although the aetiologies
of the two entities are completely different, their clinical
presentation may be quite similar and even totally
indistinguishable when based on clinical history taking. The term
“convulsive syncope” was first used by Marcus Gerbezius (1658-1718)
to describe a patient with “slow pulse, dizziness and slight
epileptic attacks” (Acierno, 1994). This phenomenon was later
described as a Stokes-Adams attack. In this report, we present a
patient with unexplained episodes of loss of consciousness,
elucidated only after video-EEG and cardiac evaluations.
Case study
A 22-year-old young lady presented with episodes of loss of
consciousness. The first episode occurred at the age of nine during
blood drawing. The second episode was triggered by a sudden
unexpected fall and subsequent episodes occurred as a reaction to a
painful stimulus. The witnesses reported that the patient was
staring without expression and irregular tonic postures and
sometimes diffuse jerks occurred. The episodes were reported to
last about 1-5 minutes and the patient always regained
consciousness without confusion soon afterwards. The patient
described a feeling of falling down before the episodes. Her
routine EEG and cranial MRI were normal. Medical history was not
significant. Her father and uncle experienced some episodes of
fainting in reaction to seeing blood, although the family history
was otherwise normal. She was admitted to our video-EEG unit to
draw blood from her for another medical condition. The recorded
parameters were 16 channel EEG (standard international
electrodes), one channel ECG, EMG and simultaneous video
recordings. During the procedure, we withdrew blood from the right
antecubital fossa. Soon after the blood withdrawal was complete,
she reported that she felt dizzy and heart rate began to slow down
(figure 1).
About 20 seconds later, complete asystole ensued and she lost
her consciousness, with an expressionless stare. At first, her head
and eyes turned to the right side with brief automatisms on the
left arm, followed by head and eye deviation to the opposite side
with an asymmetric dystonic posture of the upper extremities (figure 2).
Hyperventilation and profuse sweating were observed. These dystonic
postures subsided after about 40 seconds as the heart rhythm
reappeared. After a silent period of 10 seconds, generalized
irregular clonic jerks of the body were observed for
15 seconds. She finally began to snore and regained
consciousness after a brief state of confusion. As she recovered,
she cried and reported that she was feeling poorly.
On EEG recordings, there was diffuse slowing when the heart rate
began to slow down. When the patient lost her consciousness and
heart beating stopped, diffuse generalized slow delta waves with
high amplitude appeared, followed by complete suppression of
cerebral activity. During 40 seconds of the asystolia period,
head and eye deviation, brief automatisms and dystonic extremity
movements were observed whereas the EEG was masked by muscle
artefacts. After a silent period of 10 seconds (figure 3), body jerks
started at the same time as diffuse high amplitude delta discharges
on EEG. As these movements ceased, an irregular slow rhythm
reappeared.
In the first part of the episode with bradycardia and asystolia,
the clinical semiology was very much similar to an epileptic event
with head/eye deviations, automatism and dystonic posture. In
particular, the second phase of massive body jerks implied a
convulsive episode, although this was induced by cerebral hypoxia
with diffuse delta discharges without any epileptiform activity on
EEG.
The patient was subsequently evaluated by the cardiology
department and was re-admitted to be evaluated for cardiac
parameters. The same procedure that caused the episode was
reproduced. During the blood withdrawal, sinus bradycardia was
followed by complete sinus arrest. In addition, the blood pressure
dropped markedly but no convulsive movements were seen. According
to these findings, she was diagnosed with sinus arrest mediated by
vasovagal mechanisms.
Discussion
It is well known that cardiac diseases and syncope may strongly
resemble seizures. The studies investigating the similarities
between these conditions date back to the 1970s. It was reported
that 20% of those referred to a neurology department with a
possible diagnosis of epilepsy were subsequently considered to have
cardiac arrhythmia as a cause of their symptoms (Schott
et al., 1977).
The characteristics of convulsive symptoms occurring during the
syncopal episodes were investigated by several studies. In a study
with blood donors, the prevalence of the convulsive syncope was
found to be 0.03% (Lin et al., 1982). The authors reported
that tonic extensor spasm was the most common convulsive movement
and other complex phenomena also occurred simulating epileptic
seizures. In another study, the videometric analysis of the
episodes of the cerebral hypoxia was performed and the most
commonly observed activity was myoclonus, occurring either as
multifocal myoclonic jerks or generalized myoclonus. Additional
motor activities observed in this report were: head turns, oral
automatisms and righting movements (Lempert et al., 1994).
The cerebral electrical activity during the convulsive syncopes
was also investigated. Background slowing evolving into loss of
cerebral activity was reported in patients with malignant
ventricular arrhythmias (Aminoff et al., 1988). Later studies
also confirmed that the ictal patterns consisted of diffuse slowing
without paroxysmal activity (Fernandez Sanmartin et al.,
2003). Gelisse et al. (2007) conducted a video-EEG study of a
14-year-old boy misdiagnosed with epilepsy. They proved clinically
and neurophysiologically that the patient actually experienced
syncopal episodes. The video-EEG demonstrated a syncopal episode
due to cardiac asystole triggered by ocular compression. During the
episode, the EEG showed generalized slowing evolving into complete
cessation of cerebral electrical activity.
In order to relieve diagnostic confusion, the utility of some
diagnostic tests has been investigated. In one study, 24-hour
electrocardiographic recordings were not found to be useful (Gibson
and Heitzman, 1984). The authors reported that arrhythmia was a
useful diagnostic symptom for only 2% of the patients and argued
against the diagnostic utility of this method for syncope. Zaidi
et al., (2000) investigated patients who were previously
diagnosed with epilepsy and unresponsive to drug treatment. The
patients were subjected to a head-up tilt test and carotis sinus
massage during continuous electrocardiography, EEG and blood
pressure recordings. For 41% of the patients, an alternative
diagnosis other than epilepsy was given to explain their condition.
The authors concluded that many patients with unexplained
convulsive black-outs have a cardiovascular problem and suggested a
non-invasive cardiovascular examination for such patients. Other
studies suggest the tilt table test to be a reliable method to
differentiate between epilepsy and syncope (Grubb et al.,
1992; Sabri et al., 2006).
In agreement with previous reports, the observations of our
patient demonstrate that cardiovascular diseases may impose a great
diagnostic difficulty in the evaluation of the patients with
presumed epilepsy. To overcome this, a diligent and elaborate
investigation is needed. The interpretation of seizure semiology in
such paroxysmal events may also be misleading and other parameters,
such as ECG, should also be included during the recording and
meticulously checked during the review. When there is a doubt, the
neurologist should not hesitate to call for further cardiological
investigation.
Legend for video sequence
Disclosure
None of the authors has any conflict of interest to disclose.
This work was not supported by a grant or any other means and
has not been presented anywhere before.
References
[Acierno, 1994] Acierno L. The History of Cardiology. New
York: Parthenon Publishing Group Inc, 1994.
[Aminoff et al., 1988] Aminoff MJ, Scheinman MM,
Griffin JC, Herre JM. Electrocerebral accompaniments of
syncope associated with malignant ventricular arrhythmias. Ann
Intern Med 1988; 108: 791-6.
[Fernández Sanmartín et al., 2003] Fernández
Sanmartín M, Rodríguez Núñez A, Martinón-Torres F,
Eirís Puñal J, Martinón Sánchez JM. Convulsive syncope:
characteristics and reproducibility using the tilt test. An Pediatr
(Barc) 2003; 59: 441-7.
[Gelisse et al., 2007] Gelisse P, Serafini A,
Davy JM, Balbe M, Coubes P, Crespel A.
Video-EEG in syncopal attack due to ocular compression in an
adolescent mistreated for epilepsy. Epileptic Disord 2007; 9:
174-8.
[Gibson and Heitzman, 1984] Gibson TC, Heitzman MR.
Diagnostic efficacy of 24-hour electrocardiographic monitoring for
syncope. Am J Cardiol 1984; 53: 1013-7.
[Grubb et al., 1992] Grubb BP, Gerard G,
Wolfe DA, et al. Syncope and seizures of psychogenic
origin: identification with head-upright tilt table testing. Clin
Cardiol 1992; 15: 839-42.
[Lempert et al., 1994] Lempert T, Bauer M,
Schmidt D. Syncope: a videometric analysis of 56 episodes of
transient cerebral hypoxia. Ann Neurol 1994; 36: 233-7.
[Lin et al., 1982] Lin JT, Ziegler DK,
Lai CW, Bayer W. Convulsive syncope in blood donors. Ann
Neurol 1982; 11: 525-8.
[Sabri et al., 2006] Sabri MR, Mahmodian T,
Sadri H. Usefulness of the head-up tilt test in distinguishing
neurally mediated syncope and epilepsy in children aged 5-20 years
old. Pediatr Cardiol 2006; 27: 600-3.
[Schott et al., 1977] Schott GD, McLeod AA,
Jewitt DE. Cardiac arrhythmias that masquerade as epilepsy. Br
Med J 1977; 1: 1454-7.
[Zaidi et al., 2000] Zaidi A, Clough P,
Cooper P, Scheepers B, Fitzpatrick AP. Misdiagnosis
of epilepsy: many seizure-like attacks have a cardiovascular cause.
J Am Coll Cardiol 2000; 36: 181-4.
|
Printable version
Version PDF
