Transcript Emergency Lecture Series Syncope vs. Seizure

Emergency Lecture Series
Syncope vs. Seizure
RALUCA PANA
PGY-2 ADULT NEUROLOGY
J U L Y 1 7 TH 2 0 1 3
Introduction
 Evaluating patients with transient loss of
consciousness (TLOC) remains a challenge
 These patients fall into 2 main groups: those
with seizures and those with syncope
 15% of transient loss of consciousness are due to
seizures
 Reflex syncope remains most common etiology
with 58%
Case
22-year-old woman with a diagnosis of epilepsy since childhood
presented to the ER after passing out during a blood draw. She
recalled feeling anxious and nauseous, having a racing heartbeat,
experiencing graying of vision, and then losing consciousness. Her
boyfriend reported that her eyes rolled upward and her body became
limp before stiffening and shaking for approximately 20 seconds.
Afterward, she returned to baseline within a few minutes.
 She had been diagnosed with epilepsy because of similar loss-ofconsciousness events occurring since she was 4 years old. She had a
total of 10 such events, and half were associated with medical
procedures or orthostatic stress. She had been on anticonvulsant
medications for many years.
 The examination was normal, although she was pale and sweaty
Seizures OR Syncope?
Definitions
 Seizure
Defined as stereotyped spells caused by abnormal electrical
brain activity and can be provoked by a variety of
conditions or occur spontaneously without an identifiable
cause
 Manifestions depend on underlying neuroanatomic
substrate (spells article)
DDX of Seizure
Types of Seizures resembling syncope
Definitions
Syncope
defined as an abrupt and transient loss of
consciousness associated with inability to
maintain postural tone, often due to cerebral
hypoperfusion
DDx of Syncope
Classification of Syncope
Examples of types of syncope
 Neurocardiogenic
Lack of sympathetic vasoconstriction or vagal bradycardia
Remains most common cause, look for a trigger (pain, fear)
Includes situational syncope : during straining, coughing
etc
 Carotid Sinus hypersensitivity
Common in Elderly, syncope on neck turning
Can reproduce with carotid sinus massage
Grey Areas
 Psychogenic
Presenting as seizure or apparent syncope
Can account for up to 30% of refractory seizures
Usually PMHx of psychiatric disorders, trauma, abuse
May sometimes document during formal video EEG or tilt
table
 Convulsive Syncope
Myoclonic jerks during a syncope estimated to occur
between 12-46%, some reports 90% in blood donors
Clinical Approach to TLOC
 In 50% of cases, it is estimated to arrive at a
diagnosis by history and physical exam alone
 Thorough History taking often in the presence of
reliable informant/by standers
 Should focus on two main elements:
-Patient characteristics and past medical history
-Extremely Detailed description of the episode of
loss of consciousness
Specific Distinguishing Features
Clinical Setting:
Seizures are usually unprovoked
Syncope occurs in settings of strong emotional/painful stimuli
 recent prolonged standing or sitting, or being able to clearly
remember the loss of consciousness.
 Startle : can point to hereditary long QT syndromes
Aura/prodrome:
pre-syncopal symtoms graying of vision, light-headedness,
muffling of sounds, sitting preceding warmth or diaphoresis,
palpitation, dyspnea, chest pain
Typical Auras: rising epigastric sensation, automatisms, head
turning, purpuseless movements, macropsia , dysphasia
Distinguishing Features
 Associated Signs and Symptoms:
-Pallor and diaphoresis strongly suggest syncope
-In syncope, fall is flaccid usually, eyes are open and
gaze is upward or straight
-Tongue biting: unusual but if occurs, location is at
tip of tongue .Lateral Tongue biting is associated
with epileptic seizures
-Urinary incontinence can occur in both seizures and
syncope.
Specific Distinguishing Features
 Motor Activity:
-brief motor activity, including tonic extension of the
trunk and limbs or several clonic jerks can occur in
both conditions
-Syncopal jerks are NOT rhythmic or synchronous,
small amplitude, occur after LOC, last around 15
seconds
-Seizure : synchronous, large amplitude , long lasting ,
clearly unilateral and can occur prior to loss of
consciousness. Clearly unilateral points to seizure
Specific Distinguishing Features
• Recovery Time:
-Unconsciousness lasts less than 20sec in syncope unless
patients are kept upright
-Recovery is spontaneous and typically prompt
-Post-ictal phase can last for hours, especially in children.
-Behavior and orientation usually return after 30sec 1min
-Retrograde amnesia in the elderly has been described
Clues in the history
Events during an Attack
Events after an Attack
Patient caracteristics
Validated Discriminating Features
What about tongue biting?
 Meta-analysis by Brigo et al. In 2012 looked at
clinical relevance of tongue biting in seizures and
Psychogenic non epileptic events and evaluated
Likelihood ratio of this physical finding
 Showed a statistically significant difference in
Tongue biting prevalence between epilepsy and
PNEEs
 More Tongue biting in Epilepsy group, even higher if
it was lateral tongue biting
Studies Included
Meta-Analysis for Tongue Bite in Epilepsy
Normogram:
LR for Lateral TB vs TB no precise localization
Clinical Approach
 Another useful tool to help distinguish syncope
from seizures
 Bedside questionnaire developed by Sheldon et al
in 2002 that is validated to identify seizures in 94%
of cases
Validated Historical Criteria
 Prospectively analyzed data from 617 patients
with loss of consciouness who completed a 118
item questionnaire
 Developped Diagnostic criteria by correlating
these historic features with their final diagnosis
 They then tested the decision rule on 268 patients
 Overall accuracy in test sample was 94% with a
sensitivity of 94% for seizures
 The presence of negative criteria solves the
diagnostic problem of convulsive syncope
Bedside Questionnaire
Physical Exam
 Vital signs: orthostatic VS, irregular HR
 Performing a carotid massage to identify carotid
sinus hypersensitivity can be useful
 Cardiovascular examination: look for murmurs
suggestive of aortic stenosis, increased size and
altered location of PMI , Pericardial rub (restrictive
pericarditis), etc
Physical exam
 Thorough Neurological exam:
- VS : febrile for seizures, meningitis/encephalitis
- ENT: Tongue lacerations
- Altered mental status, post-ictal confusion
- Looks for focal neuro signs
- Previous scars (Neurosurgical)
- Signs of Neuro dx associated with Autonomic
dysfunction (PD, MSA)
To summarize...
Investigations
 Should not be guided by the specialty under
which the patient is admitted
 Rather should be guided by elements gathered in
history taking
 Recent review by Krahn et. al looked at evidence
supporting different investigation modalities in
patients with “collapse”.
 In general it is recommended to start with EKG
in all patients (can give prognostic information if
underlying structural cardiac disease)
Investigations
 Standard blood test CBC, chem 7, trops +/-
toxicology depending on clinical history
Dx yield is about 2-3%
 Prolactin levels are not useful
 CK levels are usually elevated in seizure patients,
but not always
 EEG in undifferentiated patients with TLOC yield of
1.5% similar to general population
Investigations
 EEG: interictal EEG useful when there is a
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clinical suspicion of epilepsy (focal neuro
findings or hx suggestive of epilepsy)
Timing of EEG is crucial: 50 % of patients who
present after generalized convulsion have
abnormlities on EEG within 24hours.
Within 48hrs, only 21-34% have epileptiform
activity
Younger patients have higher yield
Sleep deprived EEG may increase dx yield by
30%
Investigations
 Tilt table to detect neuro-cardiogenic syncope
Mainly in atypical stories
 Holter
diagnostic yield of about 10% when worn for 24hrs
 Electrophysiologic studies
Investigations
Imaging (CT, MRI)
 Diagnostic yield is about 5% for CT scan in
undifferentiated patients with collapse
 should be done if there is a trauma
 In the presence of focal neurological deficits
 High suspicion of first seizure
What about our case...
 This case illustrates several prototypical features of reflex syncope,
including the temporal association with a painful event, the
characteristic prodromal symptoms, and the rapid return to baseline.
 The association of the event with abnormal movements is not
inconsistent with the diagnosis of convulsive syncope, and the
association of her prior losses of consciousness with medical
procedures suggests that these events might also be due to convulsive
syncope.
 The patient underwent video-EEG monitoring, and one of her typical
events was elicited by venipuncture and associated with a prolonged
(40-second) asystolic pause, consistent with malignant reflex syncope
.
 ECG, cardiac telemetry, and echocardiography were normal, and the
patient underwent pacemaker placement to prevent further
prolonged asystoles. While the diagnosis of epilepsy could not be
completely excluded, the patient has since been able to gradually
wean antiepileptic medications and has remained seizure free.
In Summary
References
 McKeon, Vaughan, Delanty. Seizures versus Syncope. 2006, Lancet 5;
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171-80
Dijk, Thijs, Benditt et Wieling. A guide to Transient loss of
consciouness van . Nat. Rev. Neurol. 5, 438–448 (2009)
Thijs, Dijk and Bloem. Falls, Faints, Fits and funny Turns (2009) J
Neurol (2009) 256:155–167
Kaplan, Nguyen, Non epileptic Paroxysmal disorders in Adults and
Adolescents (2012). Uptodate.com
Krahn, Andrew et Dewell, Selecting Appropriate diagnostic Tools for
Evaluating the patient with Syncope/collapse 2013, Progress in
Cardiovascular Diseases 402-409.