QuestionSBA
QuestionChoice
This is less likely to be the case here as the movements described are not typical of a tonic-clonic seizure where the movements are more synchronous jerking of the limbs, with the head often remaining still. Tongue biting in epileptic seizure is more commonly a lateral bite, and incontinence is frequently reported
32584
b
Tonic-clonic seizure
QuestionChoice
This is a relatively typical description of non-epileptic attack disorder. The more informal term for this condition is a pseudoseizure. The movements described in terms of back arching and pelvic thrusting are less in keeping with a tonic-clonic seizure. The eyes tend to remain open, and making noise is less likely in true epileptic seizures. Tongue biting may occur in both true seizures and non-epileptic attacks; however in epileptic seizures, it is usually the sides of the tongue that are bitten as opposed to the tip. Other signs that would point towards non-epileptic attacks are if they always occur in the company of others or if stressful or highly emotional situations induce them
32583
a
Non-Epileptic Attack Disorder
QuestionChoice
Whilst vasovagal syncope is common in young females, the description above is more in keeping with a non-epileptic attack than a vasovagal syncope as syncopal episodes usually only last 30 seconds to 2 minutes, and any movements are also short-lived. Tongue biting is also rare in syncope, and the patient usually reports more prodromal symptoms such as disturbed vision, palpitations and feeling warm
32586
d
Vasovagal syncope
QuestionChoice
Absence seizures are a form of epilepsy most common in children and are commonly associated with being very still, fluttering of the eyelids and suddenly stopping activity. They can occur with muscle jerking and shaking, though this is less common than with other forms of epileptic seizure
32587
e
Absence seizure
QuestionChoice
There is no evidence in the case vignette that this episode is related to low blood sugar, and the blood tests are reported to be normal. It is always good to bear in mind hypoglycaemia in young women and, in particular, in diabetic patients on insulin or sulfonylureas such as gliclazide.
Symptoms of low blood sugars include sweating, dizziness, tingling lips and can cause unusual behaviour, seizures and collapse if untreated
32585
c
Hypoglycaemic episode
QuestionComment
😀😀😀
44905
User
subscriber
Serpiginous Defibrillator
QuestionComment
hip thrusting is usually specific to NEAD...
59979
User
subscriber
Jargon Hereditary
Concept
Chapter
# Summary
 
Syncope means a transient loss of consciousness and is a common emergency presentation. There are many causes with important differentials being reflex syncope, orthostatic hypotension and cardiac syncope. The term "blackouts" is commonly used to refer to a loss of consciousness, and includes differentials such as seizures. A thorough history (including a collateral if available) is important to help to differentiate the above, followed by examination including a lying-standing blood pressure. Initial investigations include an ECG, a blood glucose and consideration of a basic set of bloods to screen for abnormalities such as hyponatraemia that could trigger seizures. Emergency management encompasses ruling out serious causes, treating any injuries sustained during the episode and referral on for specialist investigations and management as appropriate.

# Definition 

Blackouts refer to episodes of transient loss of consciousness, which occur for a variety of reasons. Syncope refers to a transient loss of consciousness secondary to cerebral hypoperfusion, with syncopal presentations making up the majority of cases of blackouts.
 
# Epidemiology 
  
Blackouts are common, with an estimated 50% of the population experiencing at least one in their lifetime. 3% of emergency department presentations and 1% of hospital admissions in the UK are due to blackouts.
 
# Aetiology
 
**Causes of cardiac syncope:**

- Structural
       - Acute myocardial infarction 
       -  Aortic stenosis 
       -  Ischaemic cardiomyopathy
       -  Hypertrophic obstructive cardiomyopathy
       -  Cardiac tamponade
- Electrical 
       - Tachyarrhythmias e.g. superventricular tachycarcia (SVT), ventricular tachycardia (VT), ventricular fibrillation (VF)
       - Bradyarrhythmias e.g. sick sinus syndrome, heart block
       - Inherited channelopathies e.g. Brugada syndrome

**Causes of reflex syncope:**
 
 - Vasovagal syncope ("fainting")
 - Situational syncope e.g. following defecation, post-exercise, or straining to pass urine
 - Carotid sinus syndrome - occurs due to hypersensitivity of the carotid sinus baroreceptor

**Other causes of syncope:**
 
 - Orthostatic hypotension
 - Pulmonary embolism
 - Occult haemorrhage e.g. subarachnoid haemorrhage, GI bleeding, ruptured aortic aneurysm
 - Head trauma
 - Hypoglycaemia

 **Non-syncopal causes of blackouts:**
 
 - Seizures
 - Psychogenic pseudosyncope
 - Psychogenic non-epileptic seizures

# Symptoms and Signs
 
When taking a history and examining a patient after a blackout, there are several additional symptoms and signs to elicit that can help identify the likely cause. If the blackout was witnessed, take a collateral history also. 

**Questions to ask about before the blackout:**

- What were they doing/any triggers?
    - Exertional syncope (cardiac)
    - After exercise (vasovagal/orthostatic hypotension)
    - Head movements/pressure on neck (carotid sinus syndrome)
    - Prolonged standing (orthostatic hypotension)
    - Pain (vasovagal)
    - Repeated episodes after defecation/micturition/swallowing/coughing (situational syncope)
    - After a meal (vasovagal or orthostatic hypotension)
- Prodromal symptoms?
    - Feeling warm/hot, sweating, nausea (vasovagal)
    - Déjà vu or jamais vu (epilepsy)
- Intercurrent illness?
    - e.g. diarrhoea and vomiting leading to dehydration and hypotension
- Associated symptoms?
    - Palpitations/chest pain/shortness of breath (cardiac/PE)
    - Headache (subarachnoid haemorrhage)
    - Visual disturbance (if worse on standing may be orthostatic hypotension/vasovagal)
    - Lightheadedness (orthostatic hypotension/vasovagal)
        
**Questions to ask about during the blackout:**
 
- Any protective measures taken?
    -  e.g. hands outstretched to break fall 
    - It can be difficult to ascertain whether the patient lost consciousness
    - If protective measures were observed may be a fall rather than a blackout
    - Patients having a vasovagal may lower themselves to the floor
- Tongue biting?
    - Lateral tongue typical in epilepsy
    - Tip of tongue typical in vasovagal
- Incontinence of bowels or bladder? (epilepsy)
- Duration of loss of consciousness
    - Less than 30 seconds (suggests syncope)
    - Over 1 minute (suggests epilepsy)
    - Over 5 minutes (psychogenic causes more likely)
- Seizure activity observed?
    - Myoclonic jerks are common in vasovagal syncope
    - Prolonged limb jerking and abnormal posturing suggests a seizure
- Appearance during blackout e.g. pallor, eyes closed or open? 
 

**Questions to ask about after the blackout:**

- Any injuries sustained during the blackout?
       - Ask about site and severity
- Confusion or amnesia after conciousness regained?
       - If lasts minutes may indicate post-ictal state after a seizure
- Focal neurological signs (e.g. weakness down one side)

**Other important questions:**

- Any previous blackouts/similar events?
- Past medical history e.g. any heart disease?
- Medications (may contribute to orthostatic hypotension)
- Family history including sudden cardiac or unexplained death in young relatives
- Recreational drug and alcohol use (alcohol may exacerbate orthostatic hypotension)

**On examination:**

- Do a full set of observations including a lying standing blood pressure to assess for a postural drop
        - A fall in systolic blood pressure by 20mmHg or more or diastolic by 10mmHg or more, or a fall in the systolic to <90mmHg with symptoms indicates orthostatic hypotension
- Full systems examination focusing on the heart (e.g. any murmurs or abnormalities of the pulse?)
- Neurological examination including cognitive function (may be abnormal in the post-ictal state)
 
# Investigations
 
Initial investigations as follows should be carried out in the emergency setting; patients should also be referred for further specialist investigations (e.g. EEG for epilepsy, Holter monitoring for suspected arrhythmias) as appropriate.

- **Blood glucose** for hypoglycaemia
- **ECG** looking for arrhythmias, ischaemic changes or evidence of structural abnormalities (e.g. left ventricular hypertrophy in severe aortic stenosis)
- **Blood tests** looking for electrolyte abnormalities that could trigger seizures or arrhythmias, anaemia in haemorrhage, raised inflammatory markers in intercurrent illness, AKI in dehydration
- **Transthoracic Echocardiography** should be done in suspected structural heart disease (e.g. aortic stenosis)
- **24 hour ambulatory blood pressure monitoring** with an activity diary may be useful to assess for e.g. post-prandial hypotension
 
# Management
 
- Specific emergency management may be required for any serious cause identified (e.g. head injury, ruptured aortic aneurysm).
- Investigate for and treat any injuries resulting from the collapse and provide analgesia.
- Some patients can be discharged with reassurance and advice e.g. uncomplicated vasovagal episode, situational syncope.
- Patients with suspected epilepsy should be referred to a first fit clinic.
- Patients with suspected psychogenic causes of blackouts should also be referred for neurology assessment as these can be difficult to differentiate from epilepsy
- Patients with suspected cardiac syncope (e.g. abnormal ECG, exercise-induced syncope, heart murmur, heart failure, new/unexplained breathlessness or family history of sudden cardiac death in the young/inherited cardiac condition) should be referred for specialist review within 24 hours.
- Consider urgent referral for cardiovascular review in all patients over 65 with syncope and no prodromal symptoms.
- All patients with syncope of unclear cause should be referred for specialist cardiovascular review (with urgency based on the clinical picture)

 **Driving advice for patients with syncope:**

- Patients with unexplained syncope must inform the DVLA and their licence will be revoked for 6 months (12 months if Group 2) 
- Patients with a vasovagal whilst standing can drive and need not inform the DVLA if they are Group 1 drivers (Group 2 drivers must not drive and should inform the DVLA)
- Patients with cardiac syncope must not drive and should inform the DVLA - group 1 drivers may be allowed to drive after 4 weeks if a cause is identified and treated
- Full guidance including for seizures can be found in the references section
 
# NICE Guidelines
 
[NICE CKS Guidance on Blackouts](https://cks.nice.org.uk/topics/blackouts/)

[NICE: Transient loss of consciousness ('blackouts') in over 16s](https://www.nice.org.uk/guidance/cg109)
 
# References 
 
[DVLA guidance on transient loss of consciousness](https://www.gov.uk/guidance/neurological-disorders-assessing-fitness-to-drive#transient-loss-of-consciousness-blackouts--or-lostaltered-awareness)
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Syncope
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Neurology
Video
Concept
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Syncope
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Generalised seizures
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Non-Epileptic Attack Disorder, or pseudoseizures, often presents with unusual movements and can be triggered by emotional stress.
A 16-year-old female presents to the emergency department after an episode of loss of consciousness witnessed by her mother. Her mother reports that her daughter fell to the floor without warning then started shaking and making grunting noises. Her eyes were closed throughout, and her main movements were back arching and pelvic thrusting. She reports that she has bitten the tip of her tongue but retained continence. The episode lasted about 5-10 minutes in total.
Blood tests, urinalysis and examination findings are all normal.
What is the most likely diagnosis?
a