Seizures Flashcards
What happens in normal neuron function?
Ions flow in and out of neuron through protein channels, neurotransmitters carry the impulse and neuron receptors receive it. Neurotransmitters bind to the receptors and tell the cell to open or close the protein channel these neurotransmitters that cause the channels to open are called excitatory neurotransmitters, the neurotransmitters that cause them to close are called inhibitory neurotransmitters
What is a seizure?
A sudden uncontrolled burst of electrical activity in the brain that can cause changes in behaviour, movements, sensations or awareness
Why does a seizure occur?
There is a sudden increase of excitatory signals in an area of the brain caused by an abundance of excitation AND a limited amount of inhibition - this is known as synchronous electrical activity (occurring at the same time)
What happens when there is an abundance of excitation?
Fast or long acting active activation of NMDA receptors - this causes the protein channel to remain open causing a continuous influx of calcium ions, this causes the cell to continually send and receive signals leading to the excitation
What happens when there is limited inhibition?
Dysfunctional GABA receptors meaning the cells cannot inhibit signals, chlorine is not let into the cell and therefore continues to send signals
What is epilepsy?
The transient occurrence of signs or symptoms due to abnormal electrical activity in the brain, leading to a disturbance of consciousness, behaviour, emotion, motor function or sensation
What are some causes of epilepsy?
Most are idiopathic, drugs, metabolic medical disorders, neurodegenerative disease, CNS infection
What is a focal seizure?
Localised to one hemisphere, can be motor or sensory, can cause impaired awareness - can progress to generalised seizures
What is a generalised seizure?
disorganised electrical activity occurring in both sides of the brain with impairment of consciousness - can be: absent, tonic, atonic, tonic-clonic, myoclonic
What is an absent seizure?
Interruption of mental activity for less than 30 seconds, often so brief they are barely noticed, rarely persist in adulthood
What is aura?
A subjective sensation prior to a seizure, includes: - psychic, visual, olfactory, auditory, taste
What is a tonic-clonic seizure?
Often preceded by an aura. Has a tonic (increased tone) phase and a clonic (rhythmic jerking) phase. Respiratory muscles are affected causing cyanosis, oral secretions resulting in frothing at the mouth. Usually followed by a postical sleep
What is a postical sleep?
usually occurs after a seizure. Person shows confusion, amnesia and sometimes nausea depending on consciousness
What are some seizure symptoms?
Sudden falls, involuntary limb movements, blank spells, unexplained incontinence, episodes of confused behaviour, loss of memory, disorientation, hallucinations
What is status epilepticus?
A seizure that continues for longer than 5 mins or repeated seizures without recovery
What are some causes of status epilepticus?
Hypoxia, stroke, metabolic disturbance, alcohol intoxication/withdrawal
What are some causes of non-epileptical seizures?
Syncope, TIA, sleep disorders
Dissociative seizures, factitious seizures, psychiatric seizures
What is Münchausen’s syndrome
A rare psychological and behavioural conditions in which somebody fabricates or induces symptoms of illness in themselves
What is a dissociative seizure?
Occur when thoughts trigger a physical response
How do we manage seizures?
Move any hazards away from patient, give oxygen, protect their head if possible, new patient once seizure ends
How do benzodiazepines work?
They bind to GABA and increase the action of GABA, this opened the ion and chloride enters. Hyperpolarisation occurs and less likely to fire an action potential and so therefore a sedation and anxiolytic effect seen
What is a paramedic definition of a seizure?
is a transient, paroxysmal episode of abnormal, excessive, or synchronous neuronal activity in the brain. This electrical disturbance disrupts the normal functioning of the brain and can manifest in various motor, sensory, autonomic, or cognitive symptoms depending on the regions of the brain involved
