Seizure disorder

Question 1

Know the meanings of the terms seizure, convulsion, and epilepsy.

Answer 1

Seizure - characterized by abnormal cerebral neuronal discharges with or without loss of consciousness

Convulsion - specific seizure type where the attack is manifested by involuntary muscle contractions

Epilepsy - repeated seizures due to damage, irritation and or a chemical imbalance that leads to excessive sudden synchronous electrical charges

Question 2

Understand the physiological basis of a seizure, and describe harmful consequences of seizure activity.

Answer 2

Seizures originate in the gray matter of any cortical or subcortical area of the brain
during a seizure the brain is using more oxygen than what is available so prolonged seizures can lead to ischemia

Question 3

Understand seizure classification and differences among different types of seizures (including differences in modes of propagation).

Answer 3

Focal onset - usually from damage to an area of the brain or infection and only that part of the brain is affected

generalized onset - loss of consciousness, seizure is happening in all parts of the brain, more are presumed to be genetic

Question 4

Know the meanings of the terms aura and postictal state

Answer 4

Aura - seems like a bright light appears out of no where almost like you’re dying

Postictal state - time in when the seizure episode ends and continues until the patient returns to awareness symptoms include confusion, disorientation, anterograde amnesia

Question 5

Understand the characteristic properties of status epilepticus and the therapeutic goals in treating this state.

Question 6

Know the meaning of the term ‘paroxysmal depolarizing shift’ (PDS), and understand the electrophysiological basis of depolarization and hyperpolarization.

Answer 6

PDS consists of a large depolarization that triggers a burst of action potentials
Depolarization involves the activation of AMPA and NMDA channels by the excitatory neurotransmitter glutamate
Depolarization is followed by hyperpolarization invovling activation of GABA receptor leading to efflux of K

Question 7

Understand the electrophysiological basis of surround inhibition and the tonic and clonic phases of a generalized tonic-clonic seizure.

Answer 7

The evolution of a focal seizure to a generalized seizure invovles a loss of hyperpolarization and surround inhibition
as gaba mediated inhibition breaks down during the tonic phase action potentials propagate to distant neurons leading to a spread of seizure activity from the focus to distant site in the brain

Question 8

Describe underlying conditions or environmental perturbations that can trigger epileptic seizures.

Answer 8

brain tumor, head trauma, drugs, hemorrhage, prenatal injury

Question 9

Identify drugs that aggravate or increase the risk of epileptic seizure

Answer 9

alcohol, bupropion, theophylline, CNS stimulants, withdrawal from depressants

Question 10

generalized seizures Absence: typical or atypical

Answer 10

typical - brief loss of consciousness, staring or eye flickering, being abruptly, often repetitive, no convulsions, aura, or postictal period

Atypical - slow onset than typical, more difficult to control pharmacologically than typical