Adamolekun - Seizures Flashcards
1
Q
What is a seizure?
A
- Episode of abnormally synchronized and high frequency firing of neurons, resulting in abnormal behavior or experience
- Abnormal behavior: generalized tonic-clonic mvmts or staring episodes
- Abnormal experience: deja-vu phenomenon or different types of aura
2
Q
What is epilepsy? What are some provoking factors that need to be excluded?
A
- Chronic brain disorder of various etiologies characterized by recurrent, unprovoked seizures
1. Recurrent: single seizure cannot be described as epileptic seizure - Seizures are stereotyped, and will be similar w/time —> always a pattern (some people may be violent)
- Provoking factors that need to be ruled out include: accelerated HTN, fever, acute head trauma, metabolic disorders (like hypo- and hyperglycemia), and electrolyte disturbances like hyponatremia
3
Q
What is an easy way to distinguish partial vs. generalized seizures?
A
- Partial vs. generalized is all about HOW IT STARTS
- Pt with some awareness is def partial; generalized will start with seizure all over
4
Q
What is the value of a normal EEG in a pt (adult vs. pediatric) who has had a seizure-like episode, but you just don’t know?
A
- EEG has very little value in adult neurology if it is (-)
- Normal EEG (often hyperventilate pts during this) in pediatrics can rule out absence epilepsy, but it does NOT rule out seizures
5
Q
What is the gold standard for determining whether or not seizures are epileptic?
A
- EEG is the gold standard
- Epileptic seizures come from brain; nonepileptic may by emotional or otherwise (even if pt believes they are coming from the brain)
- Tongue biting and urinary incontinence also tend to go with epileptic, but can have with non-epileptic
6
Q
What drug can use in young, pregnant woman with absence seizures?
A
- Lamotrigine
7
Q
If a seizure presents with a “warning,” is it more likely to be focal or absence?
A
Focal
8
Q
Are provoked seizures typically focal or generalized?
A
- Typically, generalized, tonic-clonic seizures (e.g., metabolic causes)
9
Q
What are epilepsy syndromes?
A
- Groupings of similar epileptic pts according to seizure type, EEG, age of onset, prognosis, and clinical signs
- EXAMPLE: juvenile myoclonic epilepsy (JME)
10
Q
What is the epi of epileptic seizures?
A
- Prevalence: 0.5% (can be as high as 5% in countries where communities have inadequate access to primary health care facilities)
- Age-specific incidence has DEC in younger age gps, and INC in pts over 60
1. Partly the result of INC rate of strokes in this age group; these can predispose to epileptic seizures
2. Degenerative disorders and tumors in this age gp may also contribute to these #’s
11
Q
What are some of the causes of adult-onset epileptic seizures?
A
- Cerebrovascular disease, trauma, tumors, infection, cerebral degeneration
- This is for epileptic pts whose etiologies are known; majority of pts w/epileptic seizures have unknown etiology despite extensive investigations
12
Q
What are the 2 overarching classifications of seizures? How are they diagnosed?
A
- PARTIAL: focal onset seizures that emanate from a specific cortical head region, and may sometimes spread to become secondarily generalized (tonic-clonic, not myoclonic)
- GENERALIZED: no focal onset, and thought to emanate from brainstem structures, with spread to both hemispheres at the same time (myoclonic jerks are features of primary generalized, not partial that progress to secondary generalized)
- DIAGNOSIS: still a clinical one, buttressed by EEG findings (normal EEG does NOT by itself negate a clinical impression of epileptic seizures)
13
Q
What are the subcategories within partial seizures?
A
- SIMPLE: consciousness preserved
- COMPLEX: consciousness impaired
1. Pt may experience some amnesia regarding event - Both can progress to secondary generalized, where consciousness is lost and there is bilateral cerebral involvement (tonic-clonic mvmts)
- NOTE: level of consciousness is often a key to distinguishing between simple and complex
14
Q
What are the signs and symptoms of simple partial seizures?
A
- Depend on seizure focus:
1. MOTOR: may exhibit Jacksonian march (focal seizures starting in hand and marching up to arm and face on same side, for example)
2. SOMATOSENSORY: sensory cortex; present w/tingling, numbness of extremity or side of face
3. AUTONOMIC: may present with rising epigastric sensations, nausea
4. PSYCHIC: fear, deja vu, jamai vu (these and autonomic may be focused in hippocampus or limbic system) - Consciousness is intact; EEG may appear normal
- Auras: brief, partial seizures with no overt behavioral manifestations (may progress to seizure sometimes, but not do so other times)
15
Q
What are the features of complex partial seizures?
A
- Typically emanate from temporal or frontal lobes
- Impaired consciousness (NO LOC), blank stare, about 1 minute
- Oral/ipsilateral hand automatisms: chewing, lip-smacking, hand-rubbing, picking movements
- Contralateral dystonic posturing: spread of seizure to ipsilateral basal ganglia -> can be LOCALIZING bc tends to be in arm/hand contralateral to seizure focus
- Amnesia for ictal event; post-ictal amnesia and confusion (irrational talk) are common
- Focal abnormality on routine EEG
16
Q
What are the 6 types of primary generalized seizures?
A
- Absence (petit-mal)
- Tonic-clonic
- Clonic
- Tonic
- Myoclonic
- Atonic
17
Q
What are the features of absence seizures?
A
- Aka, petit-mal: most common in kids -> brief, sudden lapses in attention (briefly unresponsive: 10-20 secs)
- Baseline EEG may show 3Hz spike wave: these are pretty pathognomonic for this condition
- Staring spell
- No post-ictal confusion
- Subtle myoclonic mvmt, eyelid flutter
- No baseline neuro deficits
18
Q
What are the features of tonic-clonic seizures?
A
- Typical presentation:
1. Cry, LOC
2. Muscular rigidity (tonic)
3. Pt may fall, and tongue-biting/injury common (not invariable)
4. Rhythmic jerking (clonic)
5. Bladder/bowel incontinence (not invariable)
6. Post-ictal confusion (or combativeness), sleep - Aka, grand-mal
- REMEMBER: both simple and partial complex seizures can progress to secondarily generalized tonic-clonic seizures
19
Q
What are the typical features of a myoclonic seizure?
A
- Brief, shock-like mm contractions of head, upper, or lower extremities
- Usually bilateral and symmetrical
- Consciousness preserved: pt fully aware of event
- Precipitated by awakening or falling asleep: may be more common in AM (e.g., trouble shaving, drinking AM coffee)
- May progress into tonic-clonic
- NOTE: JME commonly presents with these
20
Q
What are the features of atonic seizures?
A
- Impaired consciousness and loss of mm tone
- Brief duration
- If seated, pt’s head will drop; may fall if standing, and injury common in this situation (pts may have to wear helmets)
21
Q
How can you dx seizure?
A
- CLINICAL DX
- Hx from pt and witnesses: aura, progression from start to finish (to help distinguish partial or generalized)
- PE and neuro exam (usually normal in pts w/epilepsy)
- CBC, CMP: to help detect abnormalities like hypoglycemia or hyponatremia
- AED levels: to detect non-compliance or inadequate dosing
- Inter-ictal EEG
- Epilepsy protocol MRI of brain in pts w/new-onset seizures
- Video EEG monitoring: may be recommended for pts w/intractable seizures
22
Q
What is the prevalence of inter-ictal epileptiform discharges in epileptic pts?
A
- Initial EEG detects epileptiform discharge in 29-55% of pts
- Serial EEG’s reveal epileptiform discharges in 80-90% of pts
- Repeat studies with sleep deprivation and extended recording times helps INC chances of detecting epileptiform discharges in pts with epilepsy
23
Q
What do you see here?
A
- EEG showing focal epileptiform discharge: seizure focus is in L anterior temporal head
- NOTE: add’l examples of epileptiform abnormalities sometimes seen in EEG’s of pts with epileptic seizures are sharp waves, spikes, and sharp-and-slow wave discharges
24
Q
What is going on here?
A
- EEG showing generalized epileptiform discharge: bilateral burst of epileptiform spike and slow wave discharges starting at red arrow
- This is typical for primary generalized seizures like juvenile myoclonic epilepsy (JME): discharge occurs simultaneously and symmetrically in both hemispheres
25
Q
What is this?
A
- EEG in absence (primary generalized) seizure
- Bilateral and symmetrical spike and wave activity at frequency of 3Hz/second is classic for petit mal
26
Q
When should you do an MRI? Why? What type?
A
- Recent-onset epilepsy in adults requires imaging sequences, including gadolinium-DPTA enhanced sequences to find 1o or 2o tumors, infection, or inflammation
- This seizure protocol MRI of brain is to evaluate for lesions or inflammatory changes
- Coronal high resolution T1-weighted volume data set through whole brain + coronal T2-weighted sequence (3mm sections) to detect hippocampal sclerosis
1. In pts w/epileptic seizures from temporal lobe, MRI evidence of hippocampal sclerosis may make them candidates for epilepsy surgery (see attached image; aka, medial temporal sclerosis)
56
Q
What kinds of tx are there for refractory epilepsy?
A
- POLYTHERAPY w/antiepileptic drugs
- VAGUS N STIMULATOR: electrical pulse generator implanted subcu on chest and lead attached to L Vagus to deliver impulses at pre-programmed intervals to stimulate Vagus (MOA unknown; image) -> 40-50% have >50% seizure reduction, but rarely seizure-free
- Epilepsy SURGERY: pts w/intractable seizures should be referred to epilepsy center for eval, incl. EEG monitoring -> suitable candidates can be referred for appropriate surgery, which may include:
1. Temporal lobectomy, lesionectomy, corpus callosotomy, corticectomy, multiple subpial transections, hemispherectomy
