Seizure Flashcards
Define seizure
Excessive abnormal neuron activity associated with alterations in sensory motor autonomic and or cognitive fucntion
Epilepsy: refers to a condition of recurrent unprovoked seizures.
Partial : involve abnormal neuronal firing within a confined population of neurons usually on one hemisphere of the brain
Simple have preserved conscious state and complex have redueced.
Absence manifest as brief dissociative states often wihtout muscle or postural change
Define status epilepticus
Unremitting seizure activity of greater than 5 minutes duration or 2 or more seizures between which there is incomplete recovery of consiousness. If not ceased by 5 minutes is unlikely to cease spontaneously
30minutes of persistent seizure is a risk for significant long term complications
Two basic types generalised convulsive status (GCSE) and nonconvulsive status epilepticus (NCSE)
Refractroy status occurs when seizure activity does not stop post benzodiazapem and a second line agent
Discuss DDX of seizure activity
CNS
- Acute ischaemic or haemorrhagic stroke
- subdural
- Central venous thrombosis
- traumatic brain injury
- acute hydrocephalus
- anoxic or hypoxic injury
- eclampsia
- neoplasm
- PRES
Infection
- meningoencephalitis
- brain abscess
Metabolic
- hepatic encephaloapthy
- hypocalcaemia
- hypoglycaemia
- hyponatraemia
- uremia
Withdrawal syndromes
- Alcohol
- antiepileptic drugs
- baclofen
- barbiturates
- benzodiazepams
Tox
CVS
- long QT
- Tachyarrythmias
Discuss Todds paresis
Postictal weaknesss of hand arm or leg taht appears following a focal motor seizure involving one side of the body – can last up to 24 hours
Highly suggestive of underlying structural abnormality as cause of seizure
Discuss secondary physiological derangements secondary to seizures.
Sympathetic stimulation leads to increase in body temperature, hr, RR serum glucose and lactic acid.
A rise in the peripheral white blood cell count without an increase in bands is also often seen.
With more prolonged convulsions hypoglycaemia, neurogenic pulmonary odema, skeletal muscle damage and rarely frank rhabdo.
Autonomic discjarge may result in faecla or urinary incontinence
Fracture dislocations can occur secondary to seizure activity
Discuss management of first time seizure
Nil need to start antiepileptic therapy if first time uncomplicated seizure(nil evidence of underlying brain structural derangement, lesions or trauma/bleed)
Seizure often misdiagnosed
<50% of first time seizure will have subsequent at 2 years
risk vs benifit for starting antiepileptics with side effects from medicaitons
Factors that increase risk of recurrence and merit discussion with neurology as an inpatient include
- Focal ictus
- status
- history of intracranial surgery or trauma
- presence of persistent neurological abnormality such as Todds
Discuss management of seizure activity in special populations
1) hyponatreamia
- hypertonic 3% 3ml/kg – in rapid sequential boluses until seizures cease
2) hypocalcaemia
- calcium chloride or gluconate
3) TCA
- Hco3 1meq/kg IV bolus repeated to keep Ph between 7..4-7.5
4) salicylate OD
- as above for TCA
5) isoniazide
- pyridoxine 5 G or 70mg/kg paeds
6) cocaine
- benzo
7) lithium
- HD
8) eclapsia
- MG
Discuss complications of Seizure
Aspiration pulmonary oedema Hypoxic ischamiec encephalopathy Hypothermia Rhabdo Lactate Drug effects Trauma from seizure Drowning
List DDX of seizure activity/seizure mimics
1) Migraine
2) TIA
3) hyperventilation episodes
4) vertigo
5) functional
List DDX of seizure activity/seizure mimics
1) Migraine
2) TIA
3) hyperventilation episodes
4) vertigo
5) functional
Discuss mechanisms for brain injury with status epilipticus
1) Excitatory amino acid neurotransmitters such as glutamate and aspartate leading to influx of calcium into neuronal cytoplasm and an osmolytic cell destruction
2) prolonged seizure activity contributes itself to neuronal damage which is compounded by hypoxia, hypoglycaemia, lactic acidosis and hyperpyrexia that accompanies prolonged seizures
Discuss management goals of status
1) rapid stabilization of airway breathing and circulation
2) termination of seizure ( clinical and electrical)
3) Identification and treatment of precipitating and perpetuating factors
4) identification and treatment of complications
Discuss resus of status, reasons for failure to control, reasons for ALOC post
Do not prise teeth apart for adjunct or bite block
- left lateral
- oxygen saftey high flow o2
- Benzo 5mg im or IV repeated in 5 minutes
- Loading with levertericitam 40mg/kg
- loading with phenytoin 20mg/kg at rate of no more than 50mg/min - rapid admin is associated with bradyarrhythmia’s and hypotension. 1gram is usually inadequate for adults and does not take affect until 40% is delivered
- third line will be intubation and ventilation with infusion
FAILURE TO CONTROL
- inadeqaute antiepileptic drug therapy
- failure to initiate maintenance antiepileptic drug therapy
- hypoxia, hypotension, cardioresp failure, metabolic disturbance untreated
- failure to identify an underlying cause
- failure to recognize medical complications (hyper-pyrexia, hypoglycaemia)
- misdiagnosis of pseudoseizures
FAILURE TO REGAIN CONCIOUSNESS
- medical complications of status (hypoxia hypoglycaemia, cerebral oedema, hypotension, hyperpyrexia)
- sedation from anti-epileptic medications
- progression of the underlying disease process
- non convulsive status epiliptucs
- subtle ongoing status epilepticus
Describe the pseudoseizure pattern
1) usually last more than 5 minutes compatred to the 1-2 that is usual for neurogenic
2) Multiple patterns tend to occur in individual patients
3) post ictal phase very short or absent
4) recall of events
5) extremity movement out of phase
6) head moving from side to side
7) forward pelvic thrusting occurs in 44% of patients with pseudoseizures and is highly suggestive of the diagnosis
Some techniques include
1) the arm drop test accompanied by avoidence
2) eyes turning away from the moving examiner
3) termination of the event when the mouth and nostrils are occluded
Fall in spo2 and rise in lactate are suggestive of seizure activity and dont generally occur in pseudoseizures
List common causes of drug induced seizures
1) Cyclic depressants
2) antihistamines
3) theophylline
4) isoniazid
5) illicit drugs such as cocaine and amphetamines.
Some medications are asscoaited with reduced seizure threshold
1) tramadol
