CNS WK 7 Epilepsy

What area of the brain is involved in amnesia?

Hippocampus

Seizure type that involves loss of postural tone for 1-2 sec

Atonic

What is the ictal phase?

the seizure itself

If you are dx with a seizure disorder you technically have what?

Epilepsy.

When would genetic epilepsy appear?

between 5-20 years

What is a petit mal seizure -AKA? -symptoms? -duration?

-aka absence. -brief loss of consciousness with arrest of behavior, -eyes stare, and often turn upward, eyelids may blink -rapidly. lasts seconds

What percentage of the population has epilepsy? (2 or more unprovoked seizures in a lifetime)

4-5%

Who is most likely to have seizures due to trauma?

5-20 years old.

6 types of Generalized seizures

1. Absence 2. Myoclonic 3. Tonic 4. Atonic 5. Clonic 6. Tonic-Clonic

Tx options for Epilepsy include...

1. GABA agonist drugs 2. Na Channel inhibitors 3. Temporal lobectomy 4. extratemporal resections 5. vagal nerve stimulator implantation 6. Modified keogenic (atkin's) diet 7. deep brain stimulation to thalamus

Name 2 things going on during seizures from an action potential standpoint.

1. lowered thresholds for firing APs = high-frequency bursts of APs, long-lasting depolarization (influx of Ca -open Na channel) 2. Recruitment of nearby neurons, synapses 3. Hypersynchronization, and synaptic reorganization

Name two types of primary generalized seizures

1. petit mal (Absence) 2. Generalized tonic clonic

The cause is unknown in how many patients with epilepsy?

1/3

What percent of epileptic cases are untreatable?

1/3

What percentage of the population will have a single seizure during their lifetime? Is this epilepsy?

10% and no.

Excessive excitability of the brain. Abnormal electrical discharge in the brain resulting in alteration of cerebral function. what is the name of this SYMPTOM?

A seizure

What is epilepsy?

A seizure disorder. chronic, recurrent, unprovoked seizures. (more than 2 seizures = epilepsy.

What is the core symptom of primary generalized seizures?

loss of consciousness, bilaterally.

What type of seizure is common in children and has a strong genetic influence?

Absence (petit mal)

Hyperventilation is a particular trigger for what type of seizure?

Absence.

What is the core symptom of complex partial seizures?

Alteration of consciousness

A person that has intense fear during a seizure has involvement of what?

Amygdala

Etiology of epilepsy.

Any TBI Genetic Congenital/perinatal acquired: Intracranial: AVM, aneurysm, infection, cyst, stroke, hemorrhage, tumor Metabolic: fluid/electrolyte disturbance, hypoxia, acidosis, drugs, heavy metal, hepatic dysfunction, post-traumatic head injury

Where do primary generalized seizures occur?

Bilateral cortex and thalamus

What are common causes of epilepsy after 30 years old?

Brain tumor vascular disease

Seizure type involves motoric spasms, periods of rigidity and relaxation, symmetrical and bilteral.

Clonic

Describe the simple partial seizure -where? -awareness maintained? -symptoms?

In the neocortical area. Awareness maintained Signs and symptoms depend on cortical region affected -vision, hearing, focal clonic activity, language disruption.

Where do seizures occur?

Cortex and especially limbic system.

T/F all seizures are convulsions.

False. all convulsions are seizures, but not all seizures are convulsions. ex) you could just have a seizure in your visual cortex and not have muscular involvement.

Todd's paralysis

Following a focal seizure there may be postictal loss of function reflecting the site of onset. ex) a clonic seiqure of the arm amy be followed by a postictal weakness of the arm.

Another name for a generalized tonic clonic seizure?

Grand Mal

What is another name for seizure?

Ictus

What is a generalized tonic clonic seizure? -definition -duration

Sudden, bilaterally symmetrical major motor seizure/convulsion with loss of consciousness -minutes

Seizure motor activity that starts in the hand area of brain and spreads up to the leg is an example of what?

Jacksonian March

What is a partial seizure that starts in one anatomic site and spreads to anatomically connected sites? Give one example

Jacksonian seizure of march. -Clonic movement starts in face, then arm, then leg.

Name the phenomenon: start stimulating one area of the brain (amygdala) with a low intensity, brief stimulation repeatedly which produces progressively longer stronger electrical afterdischarges and gradually induces behavioral seizures.

Kindling

What area of the brain should you automatically associate with COMPLEX PARTIAL SEIZURES?

Limbic system -hippocampus or amygdala, orbital frontal cortex or cingulate gyrus

Repeated focal seizures in the cortex on one side may result in the development of an epileptic focus in the homologous portion of the cortex on the other side. Eventually the secondary focus becomes indepedent and is able to sustain seizures in the absence of the primary focus. this is called....

Mirror focus

Describe the major categories/classifications of seizures

Partial OR General 1. Simple partial (Motor, sensory, autonomic) 2. Complex partial 3. Secondary Generalized 4. Generalized Seizures

What is the most common type of seizure?

Partial seizures (select part of brain involved) especially complex partial seizures.

What are common causes of epilepsy around birth?

Perinatal injury (birth to 3 years) Metabolic defect (birth-10 years) Congenital malformation (birth-10 years) Infection (birth-20 years)

List a few causes of seizures apart from epilepsy.

Provoked, Alcohol, drugs, hypoglycemia, electric shock, anoxia, trauma

What type of seizure is bilateral and has loss of consciousness BUT starts in one place and moves to another? At one point during the seizure it may be indistinguishable from a primary generalized seizure.

Secondary generalized seizure

Versive head turning (contralateral side of ictus to side of the ictus) occurs in what type of seizure?

Simple partial (motor involvement)

Symptoms besides alteration of consciousness involved inc complex partial seizures

Vertigo Hallucinations or delusions.

Name 4 symptoms of a sensory simple partial seizure.

Visual or auditory hallucinations, gustatory symptoms, vertigo

What facilitates a paroxysmal depolarization shift?

activation of NMDA receptors. -particularly abundant in the hippocampus.

What is the typically EEG patter in a generalized seizure?

bilaterally 3 slow waves per second and a poly spike.

Epileptogenesis

chronic hyperexcitable neuronal network, the process of becoming epileptic. It can be induced by stimulating the brain.

Ictal activity?

clinical and/or electrographic (EEG) activity consistent with seizure

Just GABA and inhibitory mechanisms would cause what kind of seizures?

clonic seizures

Epileptic syndrome is epilepsy plus what?

epilepsy plus a cluster of signs and symptoms, may include age distribution, prognosis, response to medication

List a few triggers of seizures

fatigue, sleep deprivation, emotional stress, hypoglycemia, fevers, EtOH, certain drugs and antibiotics, menstruation, hyperventilation Odors, flashing lights, certain types of music

How do seizures lead to brain tissue injury?

high energy expenditure -lactate accumulation in brain tissue -secondary hypoxia -acidosis = brain tissue injury (too much Ca++ exposure too many times).

What is Todd's paralysis?

impaired motor function in the affected body area due to inhibition or exhaustion in the affected brain region.

Paroxysmal depolarization shift (PDS)

intracellular manifestation of a seizure. A giant synaptic potential or intrinsic alteration of membrane properties.

Post-ictal phase

minutes to hours post-seizure. Symptoms: sleepiness, fatigue, confusion/disorientation, agitation, aggression, forgetfulness, HA

What is an automatism?

particular involuntary motor behaviors: chewing, icking at your clothing, rearranging bed sheets, lip-licking.

What is status epilepticus?

seizures lasting more than 5 minutes, 2+ seizures without interictal return to baseline.

What occurs during the pre-ictal phase?

sometimes symptoms appear beforehand such as epigastric sensations, HA, lightheadedness, depression.

Give another example of Todd's paralysis

temporary visual field loss after a seizure discharge in the visual cortex.

Subcortical, thalamic, and brainstem involvement would cause what type?

tonic seizures

Describe the pathophysiology of seizures

too much neuronal excitation without inhibitory mechanisms in place -hyperexcitable neurons = seizures. -high frequency firing action potentials.

Smell-olfaction during a seizure indicates what is involved?

uncus, amygdala

Who is most likely to get epilepsy?

young and old (birth issues, and brain tumors, vascular issues)