Seizures Flashcards
What is a seizure?
A seizure is defined as “a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain”
What is a focal seizure and its 2 types?
Focal (or partial) seizures refer to the electrical and clinical manifestations of seizures that arise from one portion of the brain.
- Simple focal (aka focal aware) seizures are those in which consciousness is preserved.
- Complex focal seizures (focal impaired awareness) include memory loss for the clinical event and impaired responsiveness at the time of the event.
What are febrile seizures?
Seizures in infancy or childhood, usually occurring between 3 months and 5 years of age, associated with high fever but without evidence of intracranial infection or defined cause.
Diagnosis is clinical, with lumbar puncture performed to exclude meningitis or encephalitis if clinical suspicion exists.
Seizure vs Syncope
Twitching and jerking are often seen with vasovagal or cardiac syncope, which can be differentiated from rhythmic jerking of all the limbs in tonic-clonic seizures. Postictal confusion is one of the key differentiating factors for seizures.
Syncope Prodrome = hot, dizzy, blurred vision, cold sweat, pallor.
May have motor, ocular and vocal features
May have incontinence
What are generalised seizures?
Generalised seizures affect your whole brain. During most of these seizures the person blacks out (loses consciousness).
What are the 6 types of generalised seizures?
- absence
- tonic
- atonic
- clonic
- myoclonic
- tonic-clonic
What is an absence seizure?
Absence (petit mal): often children, abrupt cessation of activity and responsiveness, stare into space, subtle movements eg lip smacking, blinking. No aura/postictal state, and lasting 5 to 10 seconds, several times per day.
May have decline in school performance. May be precipitated by hyperventilation and photic stimulation.
What is a tonic seizure?
Tonic seizure: the tone is greatly increased: the body, arms, or legs become suddenly stiff or tense. A person may be aware or have only a small change in awareness during a tonic seizure. They usually happen during sleep
What is an atonic seizure?
Atonic (drop) seizure: loss of muscle control, suddenly collapse. brief (only about 15 s)
What is a clonic seizure?
Clonic: repeated or rhythmic jerking muscle movements, usually affect neck, face and arms.
What is a myoclonic seizure?
Myoclonic: Brief shock-like jerks of a muscle or group of muscles in arms or legs. During a myoclonic seizure, the person is usually awake and able to think clearly.
What is a tonic-clonic seizure?
A generalised tonic-clonic seizure (grand mal) classically involves loss of consciousness and a phasic tonic stiffening of the limbs (either symmetrically or asymmetrically), followed by repetitive clonic jerking. Most severe type. Loss of bladder control, tongue biting.
What is epilepsy?
Disease of the brain defined by any of the following conditions:
- At least 2 unprovoked (or reflex) seizures occurring more than 24 hours apart
- One unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after 2 unprovoked seizures, occurring over the next 10 years
- Diagnosis of an epilepsy syndrome.
Risk factors for generalised seizures
family history
previous central nervous system (CNS) infection
head trauma
prior seizure events or suspected seizure events
history of substance use
premature birth
multiple or complicated febrile seizures
Clinical features of generalised seizures
focal neurological deficits
premonitory sensation or experience (fear, epigastric sensation, déjà vu, jamais vu)
tongue biting
bladder and bowel involvement
temporary hemiparesis
temporary aphasia
fever, nuchal rigidity, altered mental status
stereotypical aura (always the same signs)
What is Todd’s paresis?
Todd’s paresis (postictal paralysis) is temporary weakness of part of the body after a seizure. Typically lasts from one hour to thirty-six hours. Weakness on one side of the body is suggestive of focal-onset epilepsy, and generally indicates that the seizure focus is contralateral to the side of the deficit.
Attributed to the affected cortex being ‘exhausted’ or silenced due to increased inhibition
Epilepsy - investigations
electroencephalogram (EEG) (spikes or sharp waves in one temporal lobe)
blood glucose (extreme hypoglycaemia or hyperglycaemia can cause seizures)
FBC (exclude infection)
electrolyte panel (Mg, Na, Ca)
toxicology screen
head CT (focal neuro deficit)
serum prolactin (2x baseline indicates GTCS)
serum creatine kinase (CK) (high in epilepsy, normal in non-epileptic events like syncope)
lumbar puncture (exclude infection)
MRI brain
Managing an epileptic seizure
- Cushion their head with your hands or soft material.
- Removing harmful objects from nearby
- Do not restrain them or put anything in their mouth.
- When the seizure stops, check their airway and place them in the recovery position.
- Arrange emergency admission if it is their first seizure.
Acute seizure management (epileptic seizure > 5 min or > 3 seizures in an hour)
- buccal midazolam OR rectal diazepam
OR IV lorazepam if IV access established - 2nd line: phenytoin
- supportive care (ABC): secure airway, deliver 100% oxygen by mask or nasal cannula, IV access, and correct hypotension, hyperthermia, glucose and electrolyte abnormalities, and potential thiamine deficiency
Status Epilepticus
A life-threatening neurological condition defined as 5 or more minutes of either continuous seizure activity or repetitive seizures without regaining consciousness.
Status Epilepticus - management
- as for acute management > 5 min, having given first dose of benzo - repeat dose of IV lorazepam - adjunct IV phenytoin (+ cardiac monitor) - thiamine if alcohol abuse suspected if still not resolved - general anaesthetic - ITU
Rx for generalised tonic clonic seizures
1st line - sodium valproate
2nd line - lamotrigine
What are psychogenic non-epileptic seizures (non-epileptic attack)?
- previously termed pseudoseizures, epileptic-like seizures but do not have characteristic electrical discharges
patients may have a history of mental health problems or a personality disorder
Epilepsy vs Non-epileptic attack
Epilepsy: synchronous, stiff/shaking, eyes can be opened, may have cyanosis, tongue biting, sterotypical aura, bladder + bowel, 2-3 min duration. Drowsy and sleepy after
(raised serum prolactin favours epilepsy)
Non-epileptic attack: asynchronous, contorted (back arching, pelvic thrusting), eyes resist being opened, tongue biting less likely, longer duration, fluctuates (slows down and increases). Can be tearful/stressed after
Rx for partial seizures
- Carbamazepine
2. lamotrigine
What are the 3 P’s which influence entitlement to drive?
Uncomplicated faints: no alternative diagnosis and presence of 3 P’s
- provoking factors (such as pain or a medical procedure)
- prodrome (dizziness, blurring vision, sweating etc)
- postural limitation
Seizures and driving: generally patients cannot drive for 6 months following a seizure. For patients with established epilepsy they must be fit free for 12 months before being able to drive
Rx for absence seizures
first line - ethosuximide or sodium valproate
Neonatal seizures - Rx
1st line - Phenobarbitone
2nd line - Phenytoin, clonazepam
(lecture slides only mention phenytoin so for exam purpose maybe choose that?)
vigabatrin for infantile spasms
