Neurology Flashcards
(188 cards)
What is meant by syncope?
Syncope is the term used to describe the event of temporarily losing consciousness due to a disruption of blood flow to the brain, often leading to a fall. Syncopal episodes are also known as vasovagal episodes, or simply fainting.
What happens in a vasovagal episode?
Strong stimulus to vagus nerve (emotional event, pain, change in temperature)
Stimulation of the parasympathetic nervous system, counteracting the sympathetic nervous system
Smooth muscle in blood pressure relax including those delivering blood to the brain
Cerebral circulation blood pressure drops
Hypoperfusion of the brain tissue, this causes the patient to lose consciousness and ‘faint’
Patients often remember the event and can recall how they felt prior to fainting. This is called the prodrome, and involves feeling how?
Hot or clammy
Sweaty
Heavy
Dizzy or lightheaded
Vision going blurry or dark
Headache
A collateral history from someone that witnessed a syncope is essential to get an accurate impression of what happened. During a vasovagal episode they may describe the person how?
Suddenly losing consciousness and falling to the ground
Unconscious on the ground for a few seconds to a minute as blood returns to their brain
There may be some twitching, shaking or convulsion activity, which can be confused with a seizure
Seizure vs syncope - after the episode
The patient may be a bit groggy following a faint, however this is different from the postictal period that follows a seizure.
Postictal patients have a prolonged period of confusion, drowsiness, irritability and disorientation.
There may be incontinence with both seizures and syncopal episodes
Primary syncope causes
Dehydration
Missed meals
Extended standing in a warm environment, such as a school assembly
A vasovagal response to a stimuli, such as sudden surprise, pain or the sight of blood
Secondary causes of syncope?
Hypoglycaemia
Dehydration
Anaemia
Infection
Anaphylaxis
Arrhythmias
Valvular heart disease
Hypertrophic obstructive cardiomyopathy
Key points to focus on during history of a syncopal episode?
Features that distinguish a syncopal episode from a seizure
After exercise? Syncope after exercise is more likely to be secondary to an underlying condition.
Triggers?
Concurrent illness? Do they have a fever or signs of infection?
Injury secondary to the faint? Do they have a head injury?
Associated cardiac symptoms, such as palpitations or chest pain?
Associated neurological symptoms?
Seizure activity?
Family history, particularly cardiac problems or sudden death?
Syncope vs seziure - pre episode
Syncope: prolonged upright posture, lightheaded, sweatting, blurring or clouding of vision
Seziure: aura (smells, tastes, deja vu)
Syncope vs seizure - during the event
Syncope: reduced tone during the episode, return of conicouness shortly after fall
Seziure: tonic clonic activity, head turning or abnormal limb positions, tongue biting, cyanosis, lasts more than five mins
?syncope key points to elicit on examination
Are there any physical injuries as a result of the faint, for example a head injury?
Is there a concurrent illness, for example an infection or gastroenteritis?
Neurological examination
Cardiac examination, specifically assessing pulses, heart rate, rhythm and murmurs
Lying and standing blood pressure
?syncope investigations
ECG, particularly assessing for arrhythmia and the QT interval for long QT syndrome
24 hour ECG if paroxysmal arrhythmias are suspected
Echocardiogram if structural heart disease is suspected
Bloods, including a full blood count (anaemia), electrolytes (arrhythmias and seizures) and blood glucose (diabetes)
Management of fainting in children
Fainting is common in children, particularly in teenage girls. They usually resolve by the time they reach adulthood. The most important aspect of management is making a confident diagnosis and excluding other pathology.
Seizures or underlying pathology need to be managed by an appropriate specialist.
Once a simple vasovagal episode is diagnosed, reassurance and simple advice can be given to:
Avoid dehydration
Avoid missing meals
Avoid standing still for long periods
When experiencing prodromal symptoms such as sweating and dizziness, sit or lie down, have some water or something to eat and wait until feeling better
What is epilepsy?
Epilepsy is an umbrella term for a condition where there is a tendency to have seizures - transient episodes of abnormal electrical activity in the brain.
Features of Generalised Tonic-Clonic Seizures
These are what most people think of with an epileptic seizure. There is loss of consciousness and tonic (muscle tensing) and clonic (muscle jerking) movements. Typically the tonic phase comes before the clonic phase. There may be associated tongue biting, incontinence, groaning and irregular breathing.
After the seizure there is a prolonged post-ictal period where the person is confused, drowsy and feels irritable or low.
Management of tonic-clonic seizures?
First line: sodium valproate
Second line: lamotrigine or carbamazepine
Features of focal seizures
Focal seizures start in the temporal lobes. They affect hearing, speech, memory and emotions. There are various ways that focal seizures can present:
Hallucinations
Memory flashbacks
Déjà vu
Doing strange things on autopilot
Where do focal seziures start?
Temporal lobes
Focal seizure management
One way to remember the treatment is that the choice of medication is the reverse of tonic-clonic seizures:
First line: carbamazepine or lamotrigine
Second line: sodium valproate or levetiracetam
What do absence seizures look like?
The patient becomes blank, stares into space and then abruptly returns to normal.
During the episode they are unaware of their surroundings and won’t respond.
These typically only lasts 10 to 20 seconds
Which patients are typically affected by absence seizures?
Children
More than 90% of these patients will stop having them as they get older
Management of absence seizures
First line: sodium valproate or ethosuximide
How are atonic seizures characterised?
Brief lapses in muscle tone
They usually last more than 3 minutes
Atonic seizures/drop attacks typically begin in childhood. What might they be indicative of?
Lennox-Gastaut syndrome