Syncope

Syncope is a temporary loss of consciousness due to a disruption of blood flow to the brain, leading to a fall. It's also known as a Vasovagal episode or Faint. The autonomic nervous system (Vagus nerve) regulates blood flow to the brain, and when it receives a strong stimulus, such as an emotion/pain/change in temperature, it can stimulate the parasympathetic nervous system → Dilation of vessels leading to the brain → Syncope.

Primary Syncope - Also known as a simple faint. Can be due to dehydration, missed meals, prolonged standing in a warm environment, vasovagal response to stimuli e.g. sudden surprise, pain, sight of blood

Secondary Syncope - This suggests an underlying health problem e.g. hypoglycaemia, anaemia, infection, anaphylaxis, arrhythmias, valvular heart disease, hypertrophic obstructive cardiomyopathy

Pre-syncope

This is the period before the syncopal episode, and the symptoms are called the Prodrome. Patients usually describe knowing they're about to faint. These symptoms include:

• Dizzy/Lightheaded

• Hot/clammy

• Sweaty

• Visual disturbance

• Headache

Patients may also experience specific symptoms of:

• Twitching/convulsion activity, which shouldn’t be confused with a seizure

• Feeling of grogginess/tiredness after, which shouldn’t be confused with a post-ictal period (prolonged confusion, drowsiness, irritability or disorientation)

Investigations

Most important thing to do here is a detailed history (mainly to differentiate between a syncopal episode and seizure). Always ask about triggers, cardiac symptoms, symptoms of infection, neurological symptoms, family history.

Symptoms that point towards a Syncopal episode:

• Prolonged upright position before event

• Prodromal symptoms

• Reduced tone during episode

• Return of consciousness soon after falling

• No prolonged post-ictal period

Symptoms that point towards a seizure:

• Before

  • Preceding Aura

• During

  • Tonic-Clonic activity

  • Tongue-biting

  • Incontinence

  • Head-turning or abnormal limb positions

    
    

  • Cyanosis

    
    

  • Lasts 5+ minutes

• After

  • Prolonged post-ictal period