Neuro: Epilepsy and its mimics Flashcards
What is epilepsy?
Umbrella term for a condition where there is a tendancy to have seizures
Investigations used to investigate epilepsy?
Electroencephalogram (EEG) - can show typical patterns in different forms of epilepsy and support the diagnosis
MRI brain - can be used to visulaise the structure of the brain -diagnose structural problems that may be associated with seizures and other pathology such as tumours
Other to exclude alt pathology e.g. ECG
FBC, electrolyte panel
Types of seizures?
Generalised Tonic-Clonic Seizures
Focal Seizures
Absence Sezieures
Atonic Seizures
Myoclonic Seizures
Infantile spasms
Features of Generalised Tonic-Clonic Seizures
Clonic tonic myoclonus
Loss of conciousness
Tonic phase - muscle tensing, typically before clonic phase
Clonic phase - muscle jerking episodes
May be associated with tongue biting, incontinence, groaning and irregular breathing
Prolonged post-ictal period follows seizure
What is meant by post-itcal period?
Period of confusion, drowsieness, feelings of irritability or depression, following a seizure
Management of tonic-clonic seizures?
First line: sodium valproate
Second line: Lamotrigine or carbamazepine
Where do focal seizures start?
In the temporal lobes
What do focal seizures effect?
Hearing
Speech
Memory
Emotions
How might a focal seizure present?
Hallucinations
Memory flashbacks
Deja vu
Doing strange things on autopilot
Treatment of focal seizures?
‘Reverse’ of tonic clonic seizures
First line: carbamazepine or lamotrigine
Second line: sodium valproate or levetiracetam
What are absence seizures?
Typically happen in children
Patient becomes blank, stares into space and the abruptly returns to normal
Patients are unaware of their surroundings and won’t respond
These typicall only last 10-20 seconds
Over 90% of patients will see resolution with age
Treatment of absence seizures?
Sodium valproate or ethosuximide
What is an atonic seziure?
'’Drop attacks’’
Brief lapses in muscle tone
Usual under 3 minuites
Typcially begin in childhood
What syndrome may atonic seziures be indicative of?
Lennox-Gastaut syndrome
Management of atonic seizures?
First line: sodium valproate
Second line: lamotrigine
What are myoclonic seizures?
Sudden brief muscle contractions (sudden ‘jump’)
Patient remains awake during the episodes
Occur in various forms of epilepsy but typically happen in children as part of juvenile myoclonic epilepsy
Management of myoclonic seizures
First line: sodium valproate
Other options: lamotrigine, levetiracetam or topiramate
What is West syndrome?
Rare disorder starting in infancy at around 6 months of age
Characterized by clusters of full body spasms
Poor prognosis 1/3 life expectency <25 yrs
1/3 pts seizure free by 25
Also known as Infantile spasms
First line treaments of West syndrome
Prednisolone
Vigabatrin
What is status epilepticus?
Medical emergency
Seizures lasting more than 5 mins OR
2+ seizures without full recovery within 30 mins time frame
How is status epilepticus managed in hospital?
Secure airway
High conc O2
Assess cardiac and respiratory function
Check pupil and GLUCOSE - hypoglycemia can cause seziures - easily corrected
Check CBG
IV access
IV lorazepams 4mg, repat after 10 mins if continues
If seziures persist IV: phenobarbitial or phenytoin
Medical options to treat status epilepticus in the community or when IV access not obtainable?
Buccal midazolam
Rectal diazepam 10mg
IM midazolam 10mg
Focal seizures originating from what part of the brain could cause automatisms?
Temporal lobe
Stages of a seizure
Beginning phase (prodrome)
You may notice mood changes or an ‘aura’ which tells you a seizure is coming soon
Middle phase (ictal)
This is when intense electrical activity happens in the brain and symptoms of seizures occur
Ending phase (postictal)
This is the recovery stage, where you experience the aftereffects of having a seizures, such as tiredness, frustration, sickness and confusion
Exhibitory activity in the brain?
Glutamate + NMDA Receptor
Inhibitory activity in the brain?
GABA and GABAa Receptor
Pathophysiology is seizures
■ A seizure is the clinical manifestation of abnormal and excessive excitation and
synchronisation of a group of neurones within the brain
■ Therefore a loss of inhibitory (GABA mediated) signals
■ Or too strong an excitatory (NMDA/Glutamate) one
■ This imbalance can happen in any point in the brain, and local changes can lead to
generalised effects
What is the pharmacological treatment of status epilepticus?
A-E and if hypoglcemic - glucose infusion - if not
Follow emergency management plan, if unknown or do not have one:
Full dose of benzodiazepine (IV lorazepam 4mg)
Five to ten minutes after initial dose if not responded: 2nd full dose benzodiazepine (IV lorazepam 4mg)
If no response to two full doses of first line: 2nd line anti epileptic phenytoin (20mg/kg max rate 50mg/min), levetiracetam (may be quickest), sodium valproate
If convulsive status epilepticus does not respond to the second-line treatment options tried, consider the following third-line options under expert guidance:
phenobarbital or
general anaesthesia
How do benzodiazepines manage status epilepticus?
GABAa agonists: increase Cl- conductance therefore membrane resting potential is more negative so less likely to fire and stop seizure activity
Benzodiazepine options for status epilepticus?
Intravenous lorazepam
Diazepam rectally
Buccal or intranasal, midazolam
What is status epilepticus?
This condition is a medical emergency. It is defined as a single seizure lasting more than 30 minutes or recurrent without regaining consciousness. The risk of permanent brain damage increases the longer the condition persists. Status can occur in patients with pre-existing epilepsy, but may be the presenting feature of new intracranial pathology.
Which AEDs are suitable for what seizure types?
Lamotrigine, levetiracetam and valproate are good for all seizure types.
Carbamazepine, gabapentin and phenytoin are better for focal (including secondary generalised)
seizures.
Ethosuximide is the drug of choice for absence seizures.
Carbamazepine may worsen myoclonic seizures.
Presentation of complex partial seizure
Clues to the diagnosis include auras of altered smell and a sense of fear, oro-facial automatisms and altered level of awareness.
Where to complex partial seizures typically arise from?
Temporal lobe (rarely frontal lobe)
When is EEG not a useful test in a patient who has suffered a possible seizure?
EEG is not a useful test following a single episode of altered awareness – it lacks specificity and sensitivity (although it is useful for classifying epilepsy and prognosticating single seizure).
What is Juvenile myoclonic epilepsy (JME)?
A form of idiopathic generalized epilepsy.
It is a common syndrome of tonic-clonic seizures and myoclonic jerks, and sometimes absences, which begins in childhood or adolescence and often persists into adulthood. It has a genetic predisposition.
Characterized by morning myoclonus (tremors or ‘jitteriness’)
Why should a patient presenting with epilepsy have an ECG performed?
ECG is done routinely in all cases of seizure or epilepsy, since cardiac problems (chiefly arrhythmias) are a common mimic of epileptic seizures and are often treatable.
Difference in the pathology behind partial and generalised seizures?
Generalised: produced by electrical impulses from throughout the entire brain (bilateral)
Partial: Produced by electical impulsed in a relatively small part of the brain (unilateral). Epileptic discharge is confined to a discrete area of the cerebral cortex
Management of primary generalised seizures?
1st line: sodium valporate
2nd line: carbamazepine, lamotragine
First line management of secondary generalised seizure?
Sodium valporate
Managment of absence seziure?
Sodium valproate or ethosuximide
Management of focal aware (simple partial seizures)?
1st line: carbamazepine or lamotrigine
2nd line: sodium valproate or levetiracetam
Management of focal impaired awearness seziures?
1st line: carbamazepine or lamotrigine
2nd line: sodium valproate or levetiracetam
Secondary causes of epilepsy?
Febrile seziure
Idiopathic
Congenital
Birth injury
HYpoglycemia
Hyponatermia
Gastroenteritis
Stroke
Brain infection
Drug abuse
O2 depeltion
Regulations re: driving with epilepsy
Epilepsy or multiple unprovoked seizure: 12m seizure free to drive car/motor cycle, 10 years without medication for HGV
First/unprovoked seizure/isolated seizure: 6m to drive car/motorcycle (12 months if there is a causative factor that may increase risk) or 5 years under cetrain circumstances for HGV drivers
Provoked seizures: 6m to drive car/motorcycle, 5 years HGV
Dissociative seziures: 3m event free
Typical ABG in seizure?
Acidotic
PO2 low – risk of hypoxic brain injury!
Lactate high
(Hypoglycemia in hypoglycemia seziures)
Bloods on a seizing patient?
- FBC
- U&E/LFT/Bone profile
- CRP/Cultures if suspecting infective cause - meningitis, encephalitis, brain abcess
- Glucose - hypo???
- Clotting screen - secondary to bleed of clot
- Antiepileptic level if pt is on them (e.g. carbemazepine)
- Toxicology screen (mostly urine)
Management post seizure?
CT head
blood cultures
blood alcohol
examine for meningism
?LP
Close obesrvation
Discuss emergency management plan
What is the single feature most suggestive of epilepsy?
Steryotyped nature of paroxysmal events
What is syncope?
Tempoary loss of conciousness caused by a transient fall in blood pressure
Forms of syncope
Vasovagal: hypotension + bradycardia
Cardiogenic: bradycardia, tachycardia, cardiac standstill
How long is an abnormal QT interval on ECG?
Over 480ms
What is long QT syndrome?
Rare heart condition in which delayed repolarization of the myocardium following a contraction increases the risk of episodes of tosade de pointes and other life threatning arrythmias.
QTc of over 480ms is diagnositic
Sudden onset of torsade de pointes causes cerebral ischemia
Dizziness, syncope, sudden death
Can be triggered by adrenergic stimulation
Can be congenital
Can be secondary to medications such as SSRIs
Usually self terminating but may lead to VF
What can increase the risk of long QT syndrome?
Sudden adrenergic stimulation
Highest risk during bradycardia
Sudden arousal from sleep can trigger attacks
Hisotry os dizzy spells and palpitation
Family history of sudden unexpected death (including cot deaths)
Familial deafness (Jervell and Lange Nielsen syndrome)
What is a psychogenic non epileptic seizure?
Paroxysmal changes in behavior that resemble epileptic seizures but are without organic cause and simultaneous EEG changes
-Associated with Depression, borderline or avoidant personality, HX of sexual/physical abuse
-Gradual onset, asymmetrical thrashing, side to side head movements, pelvic thrusting, poor response to AEDs
Seziures vs. behaviour disorders?
seizure: sterotypes, no precipitant, no response to calming, eeg accompaniment
behaviour: not sterotypes, situational, responsive to calming, no eeg accompaniment
Difference between seziures and epilepsy?
seizure: the event
epilepsy: disease associated with spontaneously recurring seizures
What is an EPILEPTIC seizure?
An epileptic seizure is the manifestation of abnormal paroxysmal activity of a group of nerve cells in the brain
The nature of this manifestation depends upon which neurons are involved
What is a concussive seizure?
Concussive convulsions are characterized by myoclonic or tonic–clonic motor convulsions that occur within seconds of head injury.
They are thought to occur in the absence of epileptic brain activity.
Primary vs secondary generalized seziures?
Primary: whole brain is activated simultaneously
Secondary generalized: a focal seizures (epileptic discharge confined to a discrete area of cerebral cortex) spread to involve the enitre brain
Symptomatic vs idiopathic vs crypotgenic epilepsy
If epilepsy can be ascribed to a specific structural cause such as a tumour or malformation it is described as “symptomatic”
If epilepsy is believed to be of genetic origin it is described as “idiopathic”
If epilepsy is of unknown cause it is described as “cryptogenic”
Features of frontal lobe epilepsy?
‘Bizzare’ seizure
Patients move legs as if cyling on a bike
Often noisy
Usually sterotypes with normal EEG
Features of temporal lobe epilepsy?
Simple or complex partial seziures
Olfactory arua
Deja vu
Lip smacking
Automatisms
Often with focal EEG abnormalities
May be a history of prolongerd febirle convulsions in infancy
MRI imaging is indicated (e.g. hippocampal sclerosis, distinctive feature of the pathology associated with temporal lobe epilepsy)
What type of epilepsy is hippocampal sclerosis (a neuropathological condition with severe neuronal cell loss and gliosis in the hippocampus, and subiculum of the hippocampus) a feature of?
Temporal lobe
What is the operculum and how do operculum seizures present?
Brain covering the insula -
The cerebral operculum refers to the portion of the frontal, parietal, and temporal lobe adjacent to the Sylvian fissure and overlying the insula. The anterosuperior part of the operculum formed by the inferior frontal gyrus contains the frontal operculum.
Clonic facial twitching,
mastication,
salivation,
swallowing,
larygeal symptoms,
speech arrest,
epigastric aura,
fear,
autonomic phenomena (tachycardia),
gustatory hallucinations (taste),
hand numbness
What is Lennox-Gastaut syndrome and its features?
At least five of the following
onset in childhood to mid adolescence, 3-15yo
diurnal(>2/3)
brief ( S to M)
Frequent seizures (>15 in total)
Prominent initial visual hallucination, ictal blindness and post-ictal headache
Multiple seizure types that are frequent and resistent to treatment
Management of Lennox-Gastaut syndrome?
First line: sodum valproate
Second line: lamotrigine
Third line: topiramate, rufinamide, clobazam, zonisamide
Fourth line - cannabidiol (epidyolex) adjunctively with clobazam
Possibly surgery - vagal nerve stimulation or corpus callostomy
Ketogenic diet may be effective
What is Dravet syndrome?
Severe myoclonic epilepsy of infancy
Unilateral and prolonged
Often precipitate by heat of pyrexia
Development initially normal and then slows with progressive ataxia
Common AEDs which may be hazardous if used inappropriatley?
May worsen seizures: for example, myoclonic epilepsy is worsened by carbamazepine and phenytoin.
Tiagabine and vigabatrin can provoke absence status.
Gabapentin and pregabalin can make absences and myoclonic worse - should be avoided in primary generalized epilepsies
Management of drug resistant epilepsy (two unsuccessful drug trials)?
Consider resective surgery:
Temporal lobectomy or amygdalo-hippocampectomy for hippocampal sclerosis, lesionectomy, hemispherectomy, corpus callostomy, multiple subpial transection
Vagal nerve stimulation
Ketogenic diet
Management of tonic-clonic seziures?
First line: Sodium valproate
Second line: lamotrigine or carbamazepine
What is meant by tonic-clonic?
Tonic - muscle tensing
Clonus - muscle jerking
First line management of absence seizures ?
Sodium valproate
First line management of absence seizures ?
Offer ethosuximide as first-line treatment for absence seizures.
If first-line treatment is unsuccessful, offer sodium valproate as second-line monotherapy or add-on treatment for absence seizures in:
boys of all ages
girls aged under 10 years and who are unlikely to need treatment when they are old enough to have children
women who are unable to have children.
If second-line treatment is unsuccessful for absence seizures, consider lamotrigine or levetiracetam as a third-line monotherapy or add-on treatment options. If the first choice is unsuccessful, consider the other of these options.
AEDs to avoid in absence seziures?
carbamazepine
gabapentin
oxcarbazepine
phenobarbital
phenytoin
pregabalin
tiagabine
vigabatrin
How to investigate suspected seizures?
First seizure: refer child and adult 2 week investigation to diagnosing, and review modifiable risk factors for second seizure (mental health, drug use, vascular problems, sepsis)
Specialist assessment: hx, psychical ex, 12 lead ecg, metabolic changes.
Clinical imaging: structural cause suspected
EEG: awake, gives diagnosis, seizure type perform asap 72hrs.
Possibly genetic
Management of secondary generalised seizures?
Carbamazepine and lamotrigine
Which drug is first choice to treat focal aware and impaired awareness seizures
Carbamazepine
3 stage seminology of a generalise tonic clonic seziure
TONIC: loss of conciousness, strong tonic spasm, salvia and foaming at the mouth, stiffnes in chest may impare the breathing
CLONIC: jerking movements, after 1-3mins this may slow down and cause incontince of the bowel and bladder with relaxation.
POSTICTAL: unconsious for several mins as the brain recovers, gradually regains awarenss, phsycially sore
Seminology of complex partial seizures
focal impaired awarenss seizures 30seconds to 2 mins. long seizures occur when they become gernalsied with full body convulsons. expect aura(somatosensory, visual,auditory or olfactory_
Causes of status epilepticus
preexisitng diagnosis of epilepsy
AED withdrawal
non complicance to medications illict drugs
intercurrent infection
progression of underlying disease liek encepahlitis or vasculitis
What AEDs are best in pregnancy?
lamotrigine (Lamictal) and levetiracetam (Keppra)
Best AEDs in pregnancy
lamotrigine (Lamictal)
levetiracetam (Keppra)
After how long might an EEG might be abnormal following a seizure?
Up to 24hrs
Drugs associated with lowering seizure threshold?
Antibiotics: Imipenem, penicillins, cephalosporins, metronidazole, isoniazid
Antipsychotics
Antidepressents: Bupropion, Tricyclics, Venlafaxine
Tramadol
Fentanyl
Ketamine
Lidocaine
Lithium
Antihistamines
Seizure threshold lowering drugs
Antibiotics: Imipenem, penicillins,
cephalosporins, metronidazole, isoniazid
Antipsychotics
Antidepressents: Bupropion, Tricyclics,
Venlafaxine
Tramadol
Fentanyl
• Ketamine
• Lidocaine
Lithium
Antihistamines
When might propofol be used in seizure management?
Propofol can be used in intensive care if phenytoin (used following no response to benzos) fails to control the seizure at 45minutes.
BNF recommend dose for rectal diazepam,
10-20mg, max 30mg
Repeated once after 10-15 minutes if necessary
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Typical EEG pattern in absence seizures?
3 Hz spike and wave
