Neuro: Seizures Flashcards by Kristen Snyder

A paroxysmal event due to abnormal excessive or synchronous neuronal activity in the brain

Seizures

How well did you know this?

Not at all

Perfectly

A condition in which a person has recurrent seizures due to a chronic, underlying process

Epilepsy

How well did you know this?

Not at all

Perfectly

Recurrent seizures from an infection or avoidable cause. Is this epilepsy?

How well did you know this?

Not at all

Perfectly

Definition of epilepsy

2 or more UNPROVOKED seizures

How well did you know this?

Not at all

Perfectly

Classifications of seziures

Focal
Generalized
Unclear

How well did you know this?

Not at all

Perfectly

Motor, sensory, autonomic, cognitive seizures are what classification?

Focal

How well did you know this?

Not at all

Perfectly

Absence, tonic clonic, atonic, and myoclonic seizures are what classification?

General

How well did you know this?

Not at all

Perfectly

Seizure that arises from a neuronal network within one hemisphere

Focal seizures

How well did you know this?

Not at all

Perfectly

What determines the difference between a simple and complex focal seizure?

Simple –> No LOC

Complex –> Alteration in consciousness

How well did you know this?

Not at all

Perfectly

What would you expect an EEG to look like between seizures?

normal

may show brief discharges (epileptiform spikes)

How well did you know this?

Not at all

Perfectly

In focal seizures WITHOUT dyscongitive features (simple), movement is typically (clonic, tonic)

clonic

How well did you know this?

Not at all

Perfectly

Focal seizures accompanied by transient impairment of the patient’s ability to maintain normal cognition

Focal seizures WITH dyscognitive features (complex)

Pt can’t respond appropriately to visual or verbal commands during seizure and usually doesn’t remember it

How well did you know this?

Not at all

Perfectly

Thought to arise at some point in the brain but immediately and rapidly engage neuronal networks in both cerebral hemispheres

Generalized seizures

How well did you know this?

Not at all

Perfectly

Characterized by sudden, brief lapses of consciousness without the loss of postural control. Seizure lasts for a few seconds and consciousness returns as suddenly as it was lost. No postictal confusion

Typical absence seizures (generalized seizure)

How well did you know this?

Not at all

Perfectly

Electrophysiologic hallmark of typical absence seizure

generalized, symmetric, 3 hz spike-and-wave discharge that begins and ends suddenly. Seen on EEG

How well did you know this?

Not at all

Perfectly

Absence seizure with longer lapse of consciousness, associated with diffuse or multifocal structural abnormalities of the brain.

Atypical absence seizures

How well did you know this?

Not at all

Perfectly

You give anticonvulsants to a pt with a typical absence seizure and a pt with atypical absence seizure. Who will respond better?

Typical

How well did you know this?

Not at all

Perfectly

Most common seizure type resulting from metabolic derangements

Generalized, tonic-clonic seizures

How well did you know this?

Not at all

Perfectly

How does tonic-clonic seizure begin?

abrupt without warning. Some pts have vague premonitory symptoms minutes to seconds before seizure

How well did you know this?

Not at all

Perfectly

Characteristics of tonic-clonic seizures

initial phase: tonic contractions
Respirations are impaired, secretions pool in oropharynx and cyanosis develops
Contraction of jaw muscles causes biting of the tongue

How well did you know this?

Not at all

Perfectly

When observing a pt undergoing a tonic-clonic seizure, what might you see?

cyanosis, increased HR, BP, pupils dilate

After 10-20 seconds, clonic phase begins

How well did you know this?

Not at all

Perfectly

How long do typical tonic-clonic seizures last? How long is dangerous?

Typical - 1 minute

Dangerous - more than 5 minutes

How well did you know this?

Not at all

Perfectly

Describe the postictal phase of tonic-clonic seizures

unresponsiveness
Muscular flaccidity
Excessive salivation
Bowel/bladder incontinence
Confusion

How well did you know this?

Not at all

Perfectly

Sudden loss of postural muscle tone lasting 1-2 seconds.

Atonic seizures

“drop attacks”

How well did you know this?

Not at all

Perfectly

Sudden, brief muscle contraction. Normal, physiologic form is sudden jerking when falling asleep.

Myoclonic seizures

Associated with metabolic disorders, degenerative CNS dz, anoxic brain injury. caused by cortical dysfunction

Myoclonic seizures

What are the three types of epilepsy syndromes?

Juvenile Myoclonic Epilepsy (JME) Lennox-Gastaut Sydrome (LGS) Mesial Temporal Lobe Epilepsy

Characterized by bilateral jerks, single or repetitive. More common in the morning, provoked by lack of sleep. 1/3 have absence seizures, many can experience tonic-clonic seizures

Juvenile Myoclonic Epilepsy

Treatment of choice for JME

Valproate (Depakote) | Remission is relatively uncommon, but responds well to anticonvulsants

Occurs in children, associated with developmental abnormalities, perinatal hypoxia, trauma, and infection

Lennox-Gastaut Syndrome

LGS triad

1. Multiple seizure types (tonic and atonic seizures) 2. EEG showing spike-and-wave discharges/abnormalities 3. Impaired cognitive function in most cases

Prognosis of LGS

Poor, results in poorly controlled epilepsy

Most common syndrome associated with focal seizures with dyscognitive features

mesial temporal lobe epilepsy

Mixture of different feelings, emotions, thoughts, and experiences, which may be familiar or completely foreign

Mesial temporal lobe epilepsy

MRI findings on mesial temporal lobe epilepsy

Hippocampal sclerosis

What causes seizures?

Shift in the normal balance of excitation and inhibition within the CNS

What are the three clinical observations that can cause seizures?

1. Endogenous factor (factor within ourselves that makes seizures more likely) 2. Epileptogenic factor (something that transforms normal CNS that makes it more excitable) 3. Precipitating factors (induce seizures)

An otherwise normal child gets a fever and has a seizure. This is an example of what factor?

Endogenous

Following penetrating trauma to the head, the pt has seizures. This is an example of what factor?

Epileptogenic

Pt doesn't get enough sleep and has a seizure. This is an example of what factor?

Precipitating factor

What is an important factor in determining both incidence and likely causes of seizures/epilepsy?

AGE

Causes of seizures in neonates/early infancy

``` Encephalopathy Trauma Infection Congenital Metabolic D/O Drugs Hypoglycemia (CHIME TD) ```

Causes of seizures in late infancy/early childhood

Febrile seizures (most common) occurs during rising phase of fever. 1/3 have recurrence

Simple vs complex febrile seizurse

Simple: single event, brief, no risk of developing epilepsy Complex: repeated events, >15 minutes, Do have a risk of developing epilepsy)

Causes of seizures in childhood

Idiopathic Trauma Infection Tumor

Causes of seizures in adolescents

``` Acquired CNS lesion predominant, idiopathic less common Trauma genetic d/o infection, tumor illicit drug use ```

Causes of seizures in young adults

Alcohol withdrawal Trauama Illicit drugs Brain tumor

Result of alcohol withdrawal, symptoms like shakiness, irritability, change in MS, seizure

Delirium tremens

Causes of seizures in older adults

``` Cerebrovascular disease Tumor Alcohol withdrawal Metabolic disorders AD/Degenerative CNS dz Just being old ```

Initiation phase of seizures is characterized by two concurrent events:

1. High frequency bursts of action potentials | 2. Hypersynchronization

Pathophys of burst

problem with the neuron itself. Allows an influx of calcium that causes Na channels to open up, increasing action potential. Causes spike discharge on EEG. After burst, hyperpolarizing occurs mediated by GABA or K channels

What causes the spike discharge on EEG?

Synchronized bursts from a sufficient number of neurons

What normally prevents burst activity from spreading?

hyperpolarization and inhibitory neurons

Transformation of a normal neuronal network into one that is chronically hyperrexcitable.

Epileptogenesis

What are the new findings in genetic causes of epilepsy?

Ion channel mutations and Chromosomal microdeletions May be the cause of epilepsy in some patients

You are taking history from someone who had their first seizure. What 3 things do you want to establish?

1. Actual seizure or just a paroxysmal event? 2. Cause? (RF, precipitating events) 3. Is Anticonvulsant therapy required?

You are taking history from someone with prior seizurse. What 2 things is the evaluation directed toward?

1. Identify cause and precipitating factors | 2. Determine if their current treatment therapy is enough

What specifics are you looking for on PE in someone who had a seizure?

Signs of infection, trauma, drug/alcohol use, metabolic d/o (jaundice), neuro exam deficits

What labs do you order on someone who had a seizure?

Glucose!! | CMP, urine and blood tox screen, LP if suspect meningitis

What imaging do you order on someone with new-onset seizure?

MRI is better than CT CT used if assessing for infection/bleed/mass EEG can confirm electrical activity, classify seizure, and locate focus

Someone with a suspected seizure d/o has a normal EEG. Now what?

doesn't rule out epilepsy. Repeat EEG or do long term monitoring

If this is your first seizure and it is left untreated, how many will have recurrence? How many will have recurrence if the seizure is treated?

Half if untreated | 25% if treated

What lab test can tell you if someone is having a pseudoseizure?

Their prolactin level will be normal

Seizures and driving

PA state law is to suspend driver's license for 6 months. Must report seizure of LOC to PENDOT

Who should perform seizure management? What are the main goals of management?

``` Neurologist Goals: 1. control seizures 2. Avoid tx side effects 3. maintain quality of life ```

When is Antiepileptic Drug Therapy started?

After 2+ unprovoked seizures (above 50% chance of recurrence)

How many patients will be seizure free when using AED?

Half with new dx of epilepsy will be seizure free with first AED prescribed

What type of AEDs are the most problematic with interactions with warfarin and oral contraceptive therapy? (as well as anti-cancer and anti-infective drugs)

``` Enzyme-inducing AED's: Phenytoin (dilantin) Carbamazepine (Tegretol) Phenobarbital Oxycarbazepine (Trileptal) Topiramate (Topamax) ```

How do you add another AED if the first one does not control epilepsy?

1. Second med is increased to therapeutic levels before first agent is reduced 2. Second med is titrated up slowly 3. Temporary increase in side effects during overlap period until first AED is tapered off

Prognosis for patients who have failure of initial AED therapy

Fewer patients will have successful drug trial

What do you need to watch for in AED therapy?

1. Increased risk of suicide 2. Stevens-Johnson syndrome 3. Toxic epidermal necrolysis 4. Drug rash with eosinophilia and systemic symptoms

When is the period of highest risk of developing severe complications with AED?

First 2 months

Mainly used for focal seizures and neuropathic pain. SE: diplopia, hyponatremia

Carbamazepine (Tegretol)

SE of Phenytoin (Dilantin)

nystagmus, slurred speech, ataxia, drowsiness

signs of toxicity from phenytoin

gum hyperplasia hirsuitism Folate deficiency (monitor LFTs and CBC)

Widely effective treatment for all seizures, also used for migraine prophylaxis. Elevated LFTs common as well as weight gain, alopecia, and tremor.

Valproic Acid (Depakene)/Divalproex (Depakote)

Rash and dizziness common. Most effective drug for focal seizures. 1:1000 get SJS.

Lamotrigine (Lamictal)

Used for general or focal seizures and has NO interactions with other drugs! May cause decrease in WBC and anger issues

Levetiracetam (Keppra)

AED that causes weight loss. Often used for focal seizures, pain syndromes, migraines.

Topiramate (Topamax)

Who should not get topamax?

If pregnant or hx of kidney stones

What classifies someone as being in remission of seizures?

Seizure-free for 2-5 years

Predictors of relapse of epilpesy after remission

1. Abnormal EEG before/during withdrawal of AED 2. Abnormal neuro exam 3. Mental retardation

A seizure lasting >30 minutes or multiple seizures without regaining consciousness. More than half have no prior seizure history.

Status Epilepticus

Most common cause of status epilepticus

Low AED blood level

Treatment of status epilepticus

ABCs Check Glucose Benzos, phenytoin, or keppra IV General anesthesia is a last resort

Surgical option used for refractory epilepsy

Vagal nerve stimulation | Reduces seizures by 40% in up to half of those with refractory epilepsy

Most common surgical excision of brain lesion in refractory epilepsy

Resect mesial temporal lobe sclerotic lesions

What % of those who do not get seizure control in the first year ever reach remission?

60%