PAT 401 Week 4 - Part 1: Understanding Seizure Disorders and Epilepsy

Seizure

A sudden, transient disruption in brain electrical function, caused by abnormal excessive discharges of cortical neurons.

Epilepsy Diagnosis Criteria

Diagnosis based on at least two unprovoked seizures more than 24 hours apart, one unprovoked seizure with a 60% risk of recurrence after two unprovoked seizures within the next 10 years, or the diagnosis of an epilepsy syndrome.

Differentiating Epilepsy from Isolated Seizures

Epilepsy is associated with abnormal findings on EEG and MRI occurring together in a recognizable pattern, considering factors like age, time of day, triggers, and type of seizures.

Recurrence Risk after One Unprovoked Seizure

There is a 60% risk of recurrence over the next 10 years after one unprovoked seizure if two unprovoked seizures have already occurred.

Diagnostic Tools for Epilepsy

Common tools include EEG and MRI to detect abnormal brain activity and patterns related to epilepsy.

Three Phases of a Seizure

Preictal, Ictus, and Postictal phases.

Preictal Phase

Includes Prodroma (symptoms like anxiety, depression, malaise) and Aura (focal seizure causing 'peculiar sensations' before the seizure).

Ictus Phase

The actual seizure episode characterized by tonic-clonic activity and potential relaxation of bladder or bowel sphincters.

Postictal Phase Manifestations

May involve headaches, confusion, aphasia, memory loss, deep sleep, and paralysis lasting hours to days.

Cerebral Blood Flow during Seizure

Increases during a seizure.

Percentage Increase in Cerebral Oxygen Consumption during Seizure

60% increase.

Metabolic Consequence in the Brain during Seizure

Glucose depletion.

Byproduct of Seizures in Brain Tissues

Accumulation of lactate.

Classification of Seizures

Based on origin in the brain (focal or generalized onset), degree of awareness during the seizure, and level of body movement.

Focal Onset in Seizure Classification

Seizures originating in a specific brain area.

Generalized Onset in Seizure Classification

Seizures involving both brain hemispheres from the beginning.

Degree of Awareness in Seizure Classification

Determines awareness of self and environment during a seizure.

Seizure Categorization by Body Movement

Motor (observable body movements) and Nonmotor (absence of observable body movements).

Tonic Seizure

Characterized by body muscle stiffening, often leading to falling and loss of consciousness.

Atonic Seizure

Involves sudden, brief loss of muscle tone, leading to falling without loss of consciousness.

Myoclonic Seizure Features

Sudden, brief shock-like jerks or twitches of arms and/or legs without impairment of consciousness.

Tonic-Clonic Seizure Description

Abrupt loss of consciousness, body stiffening followed by shaking, potential bladder control loss, and lasts about 2 minutes.

Hyperkinetic Seizure

Involves bimanual or bipedal motor activity, sometimes with sexual automatisms and autonomic changes, with or without preserved awareness.

Sensory Focal Seizure Sensations

May involve numbness, tingling, burning sensations, flashing lights, and auditory experiences.

Cognitive Symptoms in Emotional Focal Seizures

Aphasia, hallucinations, memory impairment, cognitive attention impairment, along with emotional changes.

Autonomic Symptoms in Autonomic Focal Seizures

Blushing, pallor, heart rate changes, hyperventilation or hypoventilation, and nausea.

Manifestation of Emotional Focal Seizures

Sudden emotional state changes like fear, agitation, anger, crying, laughing, or paranoia.

Primary Focus of Nonmotor Focal Seizures

On sensory, emotional, or autonomic symptoms rather than observable motor activity.

Characteristics of Generalized Seizures

Seizures involving both brain hemispheres.

Generalized seizures

Seizures characterized by neurons being activated bilaterally, originating in both sides of the brain simultaneously, and typically involving a loss of consciousness.

Types of motor generalized seizures

Include tonic-clonic, tonic, atonic, clonic, myoclonic, myoclonic-atonic, and clonic-tonic-clonic seizures.

Difference between typical and atypical absence seizures

Typical absence seizures involve brief lapses in awareness, while atypical absence seizures have a longer duration and may include additional symptoms like muscle jerking or altered awareness.

Myoclonic seizures classification

Myoclonic seizures are classified as nonmotor generalized seizures, characterized by sudden, brief shock-like jerks of the body.

Eyelid myoclonia in generalized seizures

A type of generalized seizure characterized by brief, involuntary jerking movements of the eyelids, which may occur with or without other seizures.

Epileptic spasms onset age

Epileptic spasms typically onset between 3 and 12 months of age.

Causes of epileptic spasms

May be idiopathic, genetic, result from metabolic diseases, or occur in response to central nervous system (CNS) insults.

Movements associated with epileptic spasms

Episodes involve sudden flexion or extension movements of the neck, trunk, and extremities, ranging from subtle head nods to violent body contractions.

Frequency of epileptic spasms

Can occur in clusters, with 5 to 150 episodes happening per day.

Worsening of epileptic spasms

Typically worse when the infant is waking up or falling asleep.

EEG findings in epileptic spasms

EEG abnormalities are present, and seizure activity often increases in intensity and severity over time.

Long-term effects of epileptic spasms

Can lead to the loss of developmental milestones and result in disabilities.

Treatments for epileptic spasms

Include short course adrenocorticotropic hormone, corticosteroids, prednisone, or surgery.

Status epilepticus

Occurs due to the failure of mechanisms terminating seizures or from the initiation of mechanisms leading to abnormally prolonged seizures.

Prompt diagnosis and treatment in status epilepticus

Essential to prevent serious complications like cerebral hypoxia, intellectual disability, dementia, brain damage, and death.

Serious threats in status epilepticus

Include cerebral hypoxia, high aspiration risk, intellectual disability, dementia, brain damage, and potential death.

Long-term consequences of status epilepticus

Can include neuronal death, neuronal injury, and alterations in neuronal networks.

Childhood Absence Epilepsy Syndrome onset

Seizures typically develop between 4 and 8 years of age.

Characteristics of seizures in Childhood Absence Epilepsy Syndrome

Rhythmic eye movements, chewing motions, blank stare with lack of awareness, and swimming movements.

Duration of episodes in Childhood Absence Epilepsy

Episodes last about 10 to 20 seconds.

Primary treatment for Childhood Absence Epilepsy Syndrome

Antiepileptic drugs.

Lennox-Gastaut Syndrome onset

Typically onset between 1 and 5 years of age.

Characteristics of seizures in Lennox-Gastaut Syndrome

Include tonic-clonic, atonic, akinetic, absence, and myoclonic seizures.

Notable EEG feature in Lennox-Gastaut Syndrome

Shows a characteristic 'slow spike and wave' pattern.

Developmental outcomes in Lennox-Gastaut Syndrome

Often result in intellectual disability and delayed psychomotor development.

Treatment challenge in Lennox-Gastaut Syndrome

Due to the variety of seizure types and associated cognitive and developmental challenges.

Juvenile Myoclonic Epilepsy onset

Typically onset in adolescence.

Seizure types in Juvenile Myoclonic Epilepsy

Involve myoclonic jerks of the neck, shoulders, and arms, as well as generalized tonic-clonic seizures.

Aggravating factors for seizures in Juvenile Myoclonic Epilepsy

Lack of sleep or excessive alcohol intake.

Timing of seizures in Juvenile Myoclonic Epilepsy

Seizures often occur early in the morning.

General treatment approach for Juvenile Myoclonic Epilepsy

Drugs prescribed for lifelong management of the condition.

Unclassified epileptic seizures

Do not have distinct clinical and EEG features for proper classification.

Pseudoseizures

Nonepileptic phenomena resembling epileptic seizures.

Diagnosis of pseudoseizures

Established through video-EEG monitoring to capture the spells.

Key EEG finding in pseudoseizures

EEG is normal during clinical events associated with pseudoseizures.

Simple febrile seizures

Benign and common seizures affecting children.

Percentage of children affected by simple febrile seizures

Affect 2% to 5% of children.

Age range for simple febrile seizures

Typically occur between 3 months and 5 years of age.

Temperature for simple febrile seizures

Develop at temperatures greater than 38°C.

Duration of simple febrile seizures

Brief and self-limited, lasting less than 5 minutes.