Download Approach to Seizure Internal Medicine ELS

Najwa Al-Bustani
Neurology Resident
July 22-2011
Outline:
 Definitions.
 Status Epilepticus:
 Classification.
 Definition.
 Etiology.
 Pathophysiology.
 Evaluation.
 Etiology.
 Differential Diagnosis.
 Work-up.
 Risk of recurrence.
 Management.
 When to start AED.
 Prognosis.
 How to choose AED.
Definition:
 Seizure defined by the International League
Against Epilepsy (ILAE) as:
 A transient occurrence of signs and/or
symptoms due to abnormal excessive or
synchronous neuronal activity in the brain.
 Epilepsy: tendency for recurrent
spontaneous/unprovoked seizures.
1981 International
Classification of Epileptic
Seizures
Partial (focal)
Simple
Complex
Partial with secondary
generalization
Generalized
Absence
Myoclonic
Clonic
Tonic
Tonic-clonic
Atonic
Unclassified
seizures
2010 Classification of Epileptic
Seizures
Focal
Generalized
Tonic-Clonic
Absence
Myoclonic
Clonic
Tonic
Atonic
Unknown
Classification:
Localization related
(Symptomatic)
Temporal
Lobe
Frontal
Lobe
Parietal
Lobe
Occipital
Lobe
Etiology:
Evaluation:
 History:
 From a witness if possible >> ictal + pot-ictal period.
 Emphasize on any auras >> localization.
 New onset vs recurrent.
 Look for precipitating factors: trauma, sleep deprivation, drugs,
metabolic causes.
 Family and developmental history.
 Compliance to AED (if known for epilepsy).
Physical Examination:
 Vitals: BP-postural changes, HR.
 Complete neuro. Exam >> look for focal deficit.
 Neurocutaneous lesions.
 Dysmorphic features.
Work-up:
 CBC, renal + liver function, Ca, Mg, Glucose,
CK, Toxicology screen, AED levels.
 EKG = all patients.
 ? L.P if infection is suspected.
 CT scan = all patients.
 MRI brain = selected cases.
Cortical dysplasia – left parietal
Mesial temporal sclerosis
Work-up:
 EEG:
 Positive in 20-59% after 1st seizure.
 Sensitivity in predicting recurrence after first seizure
ranges 48-61% & specificity (patients without
epileptiform abnormalities who do not experience
recurrence) has been 71-91%.
 If done within 24 hours increases sensitivity by 15%.
 Sleep deprived increase sensitivity by 25%.
Differential Diagnosis:
Continuum June 2010 - Epilepsy
Syncope
Generalized TonicClonic seizure
Duration
Usually < 30 seconds
1-2 minutes
Precipitation
50 %
None
Falls
Flaccid or stiff
Stiff
Convulsions
80% mostly brief, arrhythmic,
multifocal or generalized
Usually little or no tonic
activity
Always 2-3 minutes, rhythmic,
generalized
Eyes
Open, transient upward or
lateral deviation
Open, often sustained
deviation
Hallucination
Late in the attack
May precede generalized
seizure in focal epilepsy
Color of the face
Pale
Cyanotic
Hypersalivation, frothing
Absent
Common
Incontinence
common
Common
Tongue bite
Rare
Common
Postictal confuson
< 30 seconds
2-30 minutes
Intense tonic stiffening
Medlink Neurology
Continuum June 2010 - Epilepsy
Risk of recurrence:
 After 1st unprovoked seizure in adults ranges from 31-
56% over 2-5 years of follow-up.
 After 2nd seizure >> 73%, and 76% after 3rd.
 Clinical factors that can increase risk of recurrence:
symptomatic etiology, abnormal neuro exam., 1st
seizure during sleep.
When to treat:
 Early treatment is justifiable for whom any seizure
have significant consequences related to driving,
working and general saftey.
 Recurrent seizures.
 Epileptiform abnormalities in EEG: generalized spike
and wave >> JME.
How to choose AED:
Definition:
 Generalized, convulsive SE in adults refers to > 30
minutes of: (International League Against Epilepsy and the
Epilepsy Foundation of America – 1993)
 Continuous seizures OR
 Two or more discrete seizures between which there is
incomplete recovery of consciousness.
 Operational definition for clinical practice: continuous
or intermittent seizures lasting more than 5 min, without
full recovery of consciousness between seizures.
 Refractory SE: when seizures fail to response to adequate
doses of at least 2 AED.
Pathophysiology:
 Development of SE is not clearly understood.
 Failure of mechanisms that normally abort an isolated
seizure.
 Abnormally persistent, excessive excitation >>>
Glutamate.
 Ineffective recruitment of inhibition >>> GABA.
Systemic & Central Pathophysiology:
Etiology:
Classification & Manifestation
Classification & Manifestation
Epilepsia Partialis Continua:
 Continuous focal motor seizure (usually clonic
movements) that remains confined to a specific body part.
 Can last up to several months and consciousness is
preserved.
 Associated conditions include non-ketotic hyperglycemia,
hepatic encephalopathy, uremic encephalopathy,
hyponatremia, Rasmussen syndrome, focal cortical lesions.
 Classically refractory to treatment – treat underlying cause.
Physical Exam.:
 Suspect subtle status epilepticus in any patient who
does not regain consciousness within 20-30 minutes of
cessation of generalized seizure activity.
 Subtle movements (eg, nystagmoid jerks of the eyes or
twitching of the shoulder) may be seen in subtle
status.
Diagnostic Work-up:
 History, neurological exam and labs as discussed
before.
 LP:
 If infection is suspected.
 Neuroimaging:
 Performed once seizures are under control.
 CT head to R/O SAH, neoplasm, stroke etc.
Diagnostic Work-up:
 EEG (esp. Continuous with video):
 Crucial, but should not delay treatment.
 Identify subtle or nonconvulsive seizure activity.
 Monitor response to treatment.
 Determine seizure type (focal vs generalized).
 Suggest etiology or prognosis.
 Differentiate seizures from non-epileptic events.
Treatment Goal:
 Immediate diagnosis and termination of seizures.
 Prevent neurologic and systemic pathology.
 For an anti-seizure drug to be effective in status
epilepticus, the drug must be administered
intravenously to provide quick access to the brain
without the risk of serious systemic and neurologic
adverse effects.
Ideal Agent: If Exists
 Easy to administer.
 Prompt onset, long-acting
 100% effective.
 No depression of cardio-resp. function or mental status.
 No other adverse effects.
Management S.E
First Line Agents:
Lorazepam
Diazepam
Second Line Agents:
Phenytoin
Fosephenytoin
Phenobarbital
Propafol
Pentobarbital
Midazolam infusion
Management:
 Seizures > 5 mins:
 IV Lorazepam @ 0.1 mg/kg (no faster than 2 mg/min);
typically does not exceed 6 mg.
 Lorazepam does not last more than 45 mins usually, so
loading with phenytoin or fosphenytoin is standard
practice.
Management:
 Give IV phenytoin @ 20 mg/kg, no faster than 50 mg/min
to avoid hypotension. Note that phenytoin is not
compatible with glucose containing solutions (it will
precipitate out).
 Alternatively, IV fosphenytoin can be used – 20 mg PE/kg
(1.5 FosPHT:1 PHT), no faster than 150 mg PE/min (lower
risk of peripheral infusion site complications).
 Cardiac monitoring required >> risk of hypotension and
cardiac arrhythmias.
 Additional maximal load of 10 mg/kg.
Management:
 If seizures persist >> refractory SE >> INTUBATION is
required. Order urgent EEG. Initiate one of the following:
 IV phenobarbital 20 mg/kg slow push (<100 mg/min).
 IV pentobarbital 5 mg/kg (<50 mg/min), then 0.5
mg/kg/h to 5 mg/kg/hr.
 IV propofol 1 to 2 mg/kg bolus. This dose may be
repeated in 5 minutes if seizures persist. Initial rate of 2
mg/kg/hr, max 5 mg/kg/hr.
Management:
 Other options for refractory SE include:
 IV Midazolam 0.2 mg/kg given over 20 to 30 seconds.
This dose may be repeated in 5 minutes if seizures
persist. Continuous infusion at 0.05 to 2 mg/kg/h
 Not routinely available:


IV Valproate bolus of 25 mg/kg to 30 mg/kg at 3
mg/kg/min.
IV Levetiracetam 20 mg/kg IV over 15 minutes.
Management:
 AEDs such as PHT, CBZ are usually maintained during
the treatment of status epilepticus, so that when the
anaesthestic is terminated, there can be longer term
protection.
 Continue previous AED.
Prognosis:
 Mortality of SE >> 22% (highest for myoclonic SE, up to
86% esp. if within 24 hr of circulatory arrest).
 RF for mortality: increased age, longer duration of seizures
(esp. > 1 hr) and aetiology of SE (cerebral anoxia
particularly bad).
 Recurrence rate 25 %, especially if progressive neurologic
disease.
 Refractory SE (30% of all SE) >> higher mortality and
morbidity.
 42 year old male, s/p resection of left frontal
astrocytoma, recently D/C from hospital. On Dilantin
and Dexamethasone.
 At home: wife witness jerky movement of Rt. UE >> LE
with aphasia >> LOC >> GTC sz. X 2 min.
 US arrived >> decreased LOC, vitals stable >> ER.
 In ER >> another GTC sz. X 1 min.
 What will you do ?
 You are the resident on-call covering RVH/MNI.
 Nurse from 3-north calls you regarding:
 45 year old male, known for TLE, admitted for work-up
for possible surgery, he takes: Tegretol, Keppra,
Clobazam. Med.s on hold to record his seizures.
 For last 30 minutes had 4 episodes of starring and lip
smacking, and few minutes ago GTC sz >> received
Ativan 2mg IV.
 Now confused, vitals stable.
 What to do next Dr. ?
 60 year old male, s/p liver Tx on immunosuppresion.
 Fever and confusion since AM.
 Wife witness lip smacking and starring for few seconds
X 2.
 Had episode of GTC sz. X 45 seconds.
 Regained consciousness but confused.
 In ER >> febrile, disoriented, aphasic.
 What will you do next ?