Seizures and strokes

Question 1

What is a seizure caused by?

Answer 1

Synchronous neuronal activity in the brain causing a variety of seizures depending on where it takes place in the brain. Normal brain activity is asynchronous - neurones firing at different times.

Question 2

What are the functions of different areas of the brain?

Answer 2

Cognitive function - frontal lobe
Motor and sensory - further back
Auditory processing - Broca’s
Understanding of speech - Wernicke’s
Visual cortex - occipital lobe

Question 3

What are the two general types of seizure?

Answer 3

Focal - part of the brain
Generalised - all of the brain

Question 4

In a focal seizure what typically happens?

Answer 4

Automatisms - smacking lips
Complex - loss of awareness
Symptoms depend on what part of the brain is affected - visual changes, shaking in one area of the body, strange feelings

Question 5

What are the other types of seizure and what do they cause?

Answer 5

Tonic - increased tone in muscles, will become stiff and rigid
Atonic - decreased tone, generalised atonic seizures can cause a drop of muscles
Myoclonic - sudden spasms called myoclonic jerks
Tonic-clonic - grand mau seizure
Absence - patient fully loses consciousness and is vacant

Question 6

What are the different phases of a seizure?

Answer 6

Prodrome - can last hours to days or be quite short where a patient has an inclination that a seizure is on its way - irritable and light headed.
Aura - just before seizure - migraine/odd sensations - change in taste and vision
Ictal - typical seizure phase - partial seizures may have symptoms similar to what patients experience in aura phase - motor changes or awareness change.
Post-ictal - cognitive depression, patient is sleepy/confused and can have a headache

Question 7

What is epilepsy?

Answer 7

2 or more unprovoked seizures

Question 8

What is meant by unprovoked?

Answer 8

Structural abnormality or lasting result of injury
Genetic
Metabolic
Autoimmune disorder
Idiopathic - no underlying cause

Question 9

What is meant by provoked?

Answer 9

Acute change that has changed the brain structure/chemistry by:
- metabolic - hypoxia, hyperglycaemia
- drugs/withdrawal
- infection especially in brain
- structural - trauma/tumour
- vascular - stroke

Question 10

How is epilepsy diagnosed and managed?

Answer 10

Clinical diagnosis largely based on history - what happened
Brain imaging and EEG
ECG’s, blood tests to rule out underlying causes
Anti-epileptic medications
Surgery to remove particular area causing seizures

Question 11

What are some antiepileptic medications?

Answer 11

Carbamazepine
Clabazam
Clonazepam
Levetriacetam
Lamotrigine
Phenytoin
Pregabalin

Question 12

What do people with epilepsy have to do to stay safe?

Answer 12

Must tell DVLA if they have had a seizure - provoked or potential epilepsy.
Safety assessments for jobs, not to take bath alone
Drug interactions
SUDEP - sudden unexplained death in epilepsy patients - unexplained more likely in tonic-clonic seizures

Question 13

What are some questions to ask patients with a history of seizures/epilepsy?

Answer 13

• type of seizure - describe what it means to them
• freq - how often
  Remission - is it controlled with medications?
  When was their last, more than usual recently?
  Duration - how long do they last - most patients have ones that last a few minutes
  Prolonged seizures are over 5 minutes, serial seizures are 3+ in an hour - concerning if not normal for the patient
  Most recent seizure
  Care plan?
  Typical recovery - how long does their post ictal phase last, what happens?
  Know their aural phase

Question 14

What is the management for a tonic clonic seizure?

Answer 14

STOP
Lower the dental chair and do not hold the patient down, remove anything easy to remove but don’t put your fingers in their mouth
Time - start stopwatch - 80% of prolonged seizures (5 minutes) will become half an hour. If patient is having a prolonged seizure when they are not known to call 999
Oxygen - encourage head, neck chin tilt to open airway
Pt can stop breathing in tonic phase - exhaled lung not breathing and will have lots of muscle activity using a lot of energy whilst not being able to breathe properly in clonic phase.
Will become hypoxic - blue, cyanosed
All patients in tonic clonic phase are given 15L of oxygen through non-rebreathe mask
Plan - if patient has care plan follow it, if they do not have epilepsy call ambulance. Monitor patient for at least an hour if not calling ambulance to rule out serial seizures.
Midazolam - buccal midazolam used in prolonged seizures, call ambulance as can cause respiratory distress

Question 15

How to manage a patient in the post-ictal phase?

Answer 15

recovery position - maintain airway
ABCDE assessment and manage as appropriate
Wean oxygen slowly - if can’t call ambulance
Discharge

Question 16

What is a psychogenic non-epilepsy seizure?

Answer 16

Longer prodrome, atypical features (crying whilst having seizure) and recovering quickly afterwards.
Cause is functional - not entirely understood, patient is aware of seizure.

Question 17

What is a stroke?

Answer 17

Acute event where blood supply to the brain is disrupted and brain tissue necroses

Question 18

Types of stroke?

Answer 18

Vascular
Ischaemic - blockade to blood flow (focal so symptoms depend on what part of brain affected), can be caused by arterial dissection.
Haemorrhagic - bleed from one of arteries supplying brain. split into those affecting small intracerebral vessels (in brain tissue) that can bleed due to high blood pressure, vessel disease from atheromatous plaques.
TIA - transcient ischaemic attack - “mini stroke” - symptoms are the same as a stroke but last for just 24 hours, sign that ischaemic stroke is forthcoming.

Question 19

What is a subarachnoid haemorrhage?

Answer 19

Bleeding that takes place on the surface of the brain
A bleed into the subarachnoid space is typically caused by a burst aneurysm. A classic sign of this is a thunderclap headache - feeling like you have been suddenly slapped on the head with a stiff neck and nausea, not tolerating bright lights.
Call 999 if suspected

Question 20

What are the risk factors for ischaemic stroke?

Answer 20

Hypertension
High cholesterol
Atherosclerosis
Diabetes
Smoking
Drinking
Atrial fibrillation - fibrillating left atrial wall disrupts normal blood flow with increased risk of clot formation
PFO - patent foramen ovale - hole in heart between right and left atrium which persists after birth - is a backroute for clots that can pass up the venous side and enter the right atrium and left atrium skipping the lungs into the systemic circulation causing stroke.

Question 21

How do we recognise strokes?

Answer 21

FAST
Face - drooping on one side, can they smile, is one eye drooping
Arm - can they lift both arms up or loss of sensation in one arm
Speech - dysarthria - difficulty in annunciating words or dysphagia - problem in understanding/producing language
Time - critical call ambulance whilst waiting - do ABCDE and manage

Question 22

How is a stroke diagnosed and managed in hospital?

Answer 22

Neurological exam
CT head - haemorrhagic may not show up
Thrombolysis - if ischaemic - clot dissolving drugs/thrombectomy - surgically removing clot 4.5 hours within symptoms starting for thrombolysis or 6 hours for thrombectomy.
Lumbar puncture/angiogram - haemorrhagic strokes - subarachnoid space carries on all way down spinal cord so take fluid from this area and test for RBC’s if bleeding doesn’t show up on CT.
Neurosurgery - fill aneurysms with coils to block up

Question 23

What to do after a stroke has taken place?

Answer 23

Seeing why and manage blood pressure, cholesterol, ECG, stenosis of arteries (removing thrombus)
Prevention with antiplatelets/anticoagulants
Statins
Blood pressure control

Question 24

What can be done to help a patient who has had a stroke function?

Answer 24

Physiotherapy
Occupational therapy
Speech and language therapy
Psychology
Nutritionist

Question 25

What are dental considerations with patients who have had a stroke?

Answer 25

Accessibility - wheelchair, communication, give information slowly
Difficulty swallowing and chewing
OH important - may be struggling to maintain
Drug interactions and side effects
Potential sensitivity to sedatives
Limit LA where possible and avoid adrenaline in gingival retraction