Epilepsy: Definition and Characteristics

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Questions and Answers

What is the definition of epilepsy?

A contagious cognitive disability

A chronic seizure disorder characterized by seizures that usually recur unpredictably in the absence of a consistent provoking factor (correct)

A neurological dysfunction that only begins in adulthood

A chronic mental illness characterized by seizures

What is the percentage of patients who experience partial seizures?

80% (correct)

90%

60%

50%

What is true about simple partial seizures?

They are always accompanied by a consistent provoking factor

They never cause loss of consciousness (correct)

They always cause loss of consciousness

They are a type of complex seizure

What is the term for seizures that start as partial seizures and then evolve to generalized tonic-clonic seizures?

Secondarily generalized seizures Signup and view all the answers

What is an example of an autonomic symptom of a partial seizure?

Sweating Signup and view all the answers

What type of seizure is characterized by a sudden loss of muscle tone?

Atonic seizure Signup and view all the answers

What is the term for a seizure that is not classified as partial or generalized?

Unclassified seizure Signup and view all the answers

At what stages of life can the neurological dysfunction of epilepsy begin?

At birth, childhood, adolescence, or adulthood Signup and view all the answers

What is the primary source of seizures in the brain?

Grey matter of any cortical or subcortical area Signup and view all the answers

What is the abnormality that leads to membrane instability in neurons?

Defect in voltage-sensitive ion channels Signup and view all the answers

What is the medication of choice for status epilepticus?

Diazepam Signup and view all the answers

Which of the following is NOT a type of neurological imaging study used to diagnose epilepsy?

Ultrasound Signup and view all the answers

Which type of epilepsy is treated with Valproic acid, Felbamate, and Lamotrigine?

Lennox-Gastaut syndrome Signup and view all the answers

What is the underlying pathophysiological mechanism of seizures?

Abnormal neuronal activity Signup and view all the answers

What is a characteristic of complex partial seizures?

Loss of consciousness Signup and view all the answers

Which type of generalized seizures is a consequence of a known or suspected underlying disorder of the CNS?

Symptomatic epilepsies Signup and view all the answers

What is the typical duration of an absence seizure?

10-30 seconds Signup and view all the answers

What is a characteristic of the tonic phase of a tonic-clonic seizure?

Respirations are interrupted Signup and view all the answers

What is a cause of unclassified seizures?

High fever, especially in infants Signup and view all the answers

What is a characteristic of atonic seizures?

Sudden loss of postural tone Signup and view all the answers

What is a common complication of epilepsy?

All of the above Signup and view all the answers

What is a characteristic of neonatal status epilepticus?

Seizures occur repeatedly with no recovery of consciousness between attacks Signup and view all the answers

Study Notes

Introduction to Epilepsy

Epilepsy is a chronic seizure disorder characterized by recurring seizures without a consistent provoking factor.
Epilepsy is not contagious, not a mental illness, and not a cognitive disability.
The neurological dysfunction in epilepsy can begin at birth, childhood, adolescence, or adulthood.

Classification of Seizures

Partial Seizures
- Simple seizures (without impairment of consciousness)
  - With motor symptoms
  - With special sensory or somatosensory symptoms
  - With psychic symptoms
- Complex seizures (with impairment of consciousness)
  - Simple partial onset followed by impairment of consciousness
  - Impaired consciousness at onset
- Secondarily generalized (partial onset evolving to generalized tonic-clonic seizures)
Generalized Seizures
- Absence
- Myoclonic
- Clonic
- Tonic
- Tonic-clonic
- Atonic
- Infantile spasms
Unclassified Seizures
Status Epilepticus

Partial Seizures

Common, occurring in 80% of patients
Simple partial seizures do not cause loss of consciousness
Signs and symptoms:
- Motor – convulsive jerking, chewing motions, lip smacking
- Sensory and somatosensory – paresthesias, auras
- Autonomic – sweating, flushing, pupil dilation
- Behavioral – hallucinations, dysphasia, impaired consciousness (rare)

Complex Partial Seizures

Impairment of consciousness
Purposeless behavior is common
Aggressive behavior (violence) automatism (e.g., picking at clothes)
Visual, auditory, or olfactory hallucinations

Generalized Seizures

Affecting both hemispheres
3 types:
- Idiopathic epilepsies (age-related, genetic origin)
- Symptomatic epilepsies (consequence of a known/suspected underlying disorder of CNS)
- Cryptogenic epilepsies (hidden course, age-related)

Absence Seizures (Petit Mal)

Alterations of consciousness (absence) lasting 10-30 seconds
Staring (with occasional eye blinking) and loss of postural tone
Onset occurs from 3-16 years, disappearing by 40 years

Other Types of Seizures

Myoclonic: sudden, involuntary jerking of facial, limb, or trunk muscles
Clonic: sustained muscle contractions alternating with relaxations
Tonic: sustained muscle stiffening
Tonic-clonic (grand mal): sudden loss of consciousness, followed by tonic and clonic phases
Atonic (drop attacks): sudden loss of postural tone, primarily in children

Causes of Epilepsy

Stroke
Brain tumor
Brain infection
Past head injury
Drug use, alcohol withdrawal
Epilepsy may occur with:
- Metabolic problems
- Other neurological conditions
- Genetic factors
- Developmental disabilities
- Autism
- Cognitive impairments

Pathophysiology

Paroxysmal discharges in cortical neurons
Abnormal firing of neurons
Breakdown of normal membrane conductance and inhibitory synaptic currents
Abnormality of potassium conductance
Defect in voltage-sensitive ion channels
Deficiency in membrane ATPase
Membrane instability promotes deficiency of inhibitory neurotransmitters and increase in excitatory neurotransmitters
Abnormal neuronal activity

Diagnosis

Electroencephalogram (EEG)
Neurological imaging studies:
- Magnetic Resonance Imaging (MRI)
- Functional MRI (fMRI)
- Computed Tomography (CT)
- Positron emission tomography (PET)
- Single-photon emission computerized tomography (SPECT)

Management

Status epilepticus: Diazepam, Phenytoin, Phenobarbital
Psychomotor seizure: Phenytoin
Lennox-Gastaut syndrome: Valproic acid, Felbamate, Lamotrigine, Topiramate, Rufinamide

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Description

Learn about the definition and characteristics of epilepsy, a chronic seizure disorder. Discover how it is caused by abnormal cortical neuron activity and is not contagious or a mental illness.