L13: Brain Rhytms Epilepsy Flashcards
What is a seizure as a result of
Excessive asynchronous neuronal discharge
What is an epilepsy
A tendency to recurrent seizures (2+ seizures over 24 hours apart)
What are the risk factors for epilepsy
Underlying CNS problem
Family history
Prolonged atypical febrile convulsion
What are the 2 seizure types
Focal (partial) Bilateral convulsive (generalised)
Wha is focal (partial seizure)
When the network is confined to one area of the brain
What is bilateral (generalised) seizure
Network starts in both sides of the brain simultaneously
What are the symptoms of focal seizures
depends on where the seizure originates and spreads to:
Somatosensory symptoms of one side of the body e.g tingling
Motor symptoms of jerking of body and head
Autonomic symptoms of sweating, flushing, pallor, tightness of throat and epigastric sensation (butterfly stomach)
Visual symptoms of flashes of light
Auditory (hearing) symptoms of ringing or hissing noises
What are the generalised seizures types
Absence Myoclonic Tonic Tonic clonic Atonic
What is a tonic clonic (convulsion) seizure
A seizure that has 2 phases of:
Tonic: stiffness of muscles
Clonic: jerking phase
What is a absence seizure
Sudden alteration of awareness person may seem like they are daydreaming and this can be unnoticed by other and are followed by normal activity later
What is myoclonic seizures
Sudden jerk of both of the upper limbs
What is tonic seizure
Sudden stiffening of the body
What is atonic seizure
Loss of muscle tone
What are the types of partial seizures
Simple: person is aware but cannot control function or behaviour
Complex: impaired conscious with no control over functions and behaviour
What has to happen for a diagnosis of epilepsy
2 or more stereotyped seizure attacks
What phases can a seizure have
Ictal phase
Post ictal phase
What is the ictal phase
Seizure itself
What is the post ictal phase
Phase after the seizure with confusion, fatigue or muscle pain
What is the ictal phase associated with
Warning smell Vocalisation Frothing of mouth Incontinence Lateral tongue biting
What are the post ictal symtoms
Headache
Myalgia (muscle pain)
If the seizure occurs in the frontal lobe what can appear
Minimal post ictal confusion
Bizarre behaviours
How can we examine someone with a seizure
ECG
Blood test
Imaging MRI
EEG
Why is an ECG essential
A change in heart rhythm can lead to a seizure or vice versa
With a blood test what do we look for
Kidney and liver function
Infective screen for meningitis illness- inflammation indicators
Drug levels of cocaine, alcohol and anti-psychotics
What increases the risk of seizures
Excessive alcohol intake
What is an ECG used for
Establish localisation
What are the causes of seizures
Genetic Previous febrile convulsion Infection Autoimmune Metabolic Toxic Tumours
What can previous febrile convulsions lead to
Scarring in the hippocampus
What type of infection can lead to seizures
Meningitis
Encephalitis
What are the metabolic factors that can lead to seizures
Hypocalcaemia
Hyponatriemia
Hypoglycaemia
What are the toxic factors that can lead to seizures
Alcohol
Cocaine
Amphetamine
Anti depressants
What are the common structural lesions that can cause seizures
Diseases of small vessels
Intracranial tumour
Hippocampus sclerosis
What are the advantages of using a EEG
Painless
Non invasive
What are the disadvantages for using an eeg
Seizures can be deep enough to record it
When does treatment with medication for epilepsy start
After the second seizure
What medication is used to treat epilepsy
Anti epileptic drugs
When we start anti-epileptic drug treatment how long does it last
At least 2 years from the last seizure
What are the factors we have to consider before starting anti epileptic drugs
1) drugs can bring side effects so the doses have to be titrated very slowly
2) valproate can be teratogenic for a fetus
What are the surgical options for epilepsy
- resection i.e take out the tumour
- vagal nerve stimulation
- deep brain stimulation
What is vagal nerve stimulation
1) Implantation of a pacemaker into the chest wall that has a lead going up to the vagus nerve in the neck
2) when there is a increase in heart rate the lead delivers an electrical impulse to shorten the seizure
What are the lifestyle advices that we can give for epilepsy
Minimise alcohol and drugs
Regular sleep
Ketogenic diet
What is a status epilepticus
A convulsive seizure that lasts for over 5 minutes without recovery (emergency situation)
What are the anti-epileptic drugs used in focal epilepsy
Carbamazepine
Lamotrigine
Oxcarbazepine
What are the anti-epileptic drugs used in generalised seizures
Sodium valproate (teratogenic)
Lamatrigine
Levetiracetam
