Seizures and Epilepsy Flashcards
A transient episode with signs or symptoms of abnormal excessive synchronous neuronal activity in the brain
Seizure
Physical manifestations of a seizure vary based on the pattern of network involvement in the
Brain
A seizure involving the left motor cortex will produce features characterized by
Excessive function of that region
What are the two major types of a seizure?
Focal or General
Bilateral tonic stiffening of extremities alternating with clonic jerking
Generalized tonic-clonic convulsion
Has impaired consciousness with sympathetic symptoms such as tachycardia and mydriasis
Generalized tonic-clonic convulsion
Seizure without alteration of consciousness (focal aware)
Simple partial seizure
Seizure with alteration of consciousness (focal impaired awareness)
Complex partial seizure
Focal to bilateral tonic-clonic seizure
Secondary generalized seizure
Manifestation is related to brain region involved
- May be an aura
- No alteration of awareness
Simple partial seizure
A simple partial seizure may progress into a
CPS or GTC seizure
A post-ictal deficit may be seen with a
Simple partial seizure
Focal-onset seizure with alteration of awareness
Complex partial seizure
Typically characterized by staring and poor/no responsiveness
Complex partial seizure
May involve gaze deviation, (forced) head deviation, or unilateral/asymmetric limb involvement
Complex Partial Seizure (CPS)
Complex partial seizures may progress to
GTC seizure
A new term for focal seizure to bilateral tonic-clonic seizure
Secondary generalized seizure
Seizure activity begins in one brain region then spreads to involve the rest
Secondary Generalized Seizure
Secondary Generalized Seizures may spread slowly starting as a
SPS or CPS
May spread fast, only manifesting as a generalized (bilateral) tonic-clonic convulsion
Rapidly secondary generalized seizure
Electrodes capture electrical activity from cortex
Electroencephalogram (EEG)
To best capture epileptiform activity, capture
Stage 2 sleep
Photic stimulation may demonstrate photosensitive epilepsies, such as
JME or Reflex epilepsy
May trigger seizures such as absence, or accentuate focal slowing
Hyperventilation
Show focal spike-and-wave activity on an EEG
Focal-onset seizures
Shows generalized spike-and-wave activity on an EEG
Primary Generalized Seizures
Looking for an underlying structural lesion as the source of a focal-onset seizure, e.g. stroke, tumor, hippocampal sclerosis, and many more
MRI of the brain
A disorder of the brain that results in seizures that are recurrent, unprovoked, and sterotyped
Epilepsy
Multiple events daily, can be over a hundred seizures per day
- Usually lasts more than 10 seconds
- Contribute to poor academic performance
Childhood absence epilepsy
Childhood absence epilepsy is often triggered by
Hyperventilation
The EEG for childhood absence epilepsy shows
3 Hz generalized spike-and-wave
Characterized by brief, bizarre, and nocturnal seizures
Frontal Epilepsy
Characterized by sensory based seizures
Parietal Epilepsy
Characterized by seizures with formed visual phenomena
Occipital Epilepsy
Nighttime focal onset or rapid secondary generalized seizure
-Most common type of childhood epilepsy
Benign Rolandic Epilepsy
Characterized by speech arrest, drooling, “gurgling,” facial tonic-clonic activity, facial hemisensory
-Ages 4-15 and most common around 7
Benign Rolandic Epilepsy
What does the EEG of benign Rolandic Epilepsy show>
Bilateral independent centrotemporal spikes
Characterized by multiple seizure types: axial tonic, atonic, atypical absence, and more
Lennox-Gastaut Epilepsy
Can start anywhere from infancy to 14 years of age, mostly commonly 2-3 years old
-More common in boys
Lennox-Gastaut Epilepsy
Lennox-Gastaut Epilepsy is characterized by
Cognitive impaitment or regression
What does the EEG for Lennox-Gastaut show?
Slow spike-and-wave
West syndrome: combination of spasms, hypsarrhythmia, and developmental regression
-onset between 3 and 18 months
Infantile spasms
Combination of spasms, hypsarrhythmia, and developmental regression
West syndrome
Flexor, extensor, or flexor-extensor events occurring in clusters around sleep-wake transition
Infantile spasms
EEG shows hypsarrhythmia: chaotic, high-amplitude, multifocal spikes, electrodecrement
Infantile Spasms
Certain populations are more vulnerable such as children affected with trisomy 21 or tuberous sclerosis
Infantile Spasms
How do we treat West Syndrome/Infantile Spasms?
ACTH, vigabatrin, steroids, and ketogenic diet
A combination of increased neuronal excitability, hypersynchronization, and inability to self-terminate
Seizures
Synaptic connectivity leading to propogation
Hypersynchronization
Failure of negative feedback or feed forward loop
Inability to self-terminate
Epilepsies with genetic underpinning encode for proteins in
Ion Channels
Particularly prone to synchronized bursts of activity
Cerebral Cortex and Hippocampus
The recurrence rate of single idiopathic seizures is
~50%
Treatment is typically done following the
Second Seizure
About 40% of patients are seizure free after one
AED
What percentage of additional patients are seizure free on two AEDs?
20%
Injection of an anesthetic (sodium amobarbital (Amytal) or sodium methohexital) into the right or left internal carotid artery
-Test each hemisphere for memory and language
Wada Test
What is the success rate for surgery on temporal lobe epilepsy?
50-80%
What is the surgical success rate for extra temporal lobe epilepsy?
Nearly 40%
Traditionally defined as:
- One continuous seizure > 30 minutes
- OR recurrent seizures without regaining consciousness between seizures for > 30 minutes
Status Epilepticus
What is the acute management for status epilepticus?
ABCs, IV lorazepam or diazepam, or fosphenytoin
