L4: Epilepsy Flashcards
Def of Seizure
- A transient neurologic sign and/or symptom due to abnormal, excessive, synchronous neuronal activity in the brain.
- Defined as acute symptomatic seizures or provoked seizures.
Cause of Seizure
- 25% have a clearly identifiable, temporally associated cause.
Incidence of Seizure
- A very common neurological problem.
- Affects 10% of individuals at some point in their lives.
Def of Epilepsy
- Disease of the CNS characterized by:
- Enduring predisposition to generate epileptic seizures
- Neurobiological, cognitive, psychological, and social consequences of this condition.
- Defined as two or more unprovoked seizures
Cause of Epilepsy
- Having no identifiable acute, proximal cause
Incidence of Epilepsy
- The most common try disorder of brain.
It has an age-specific incidence:
- Highest in the very young (20 y)
- Highest in the very old (75y).
Difference between Seizure & Stroke in one sentence
- Seizure → Event
- Epilepsy → Recurrent unprovoked seizures
Etiology of Seizures
Etiology of Seizures
- Those who have identifiable Causes
Etiology of Seizures
- Those who don’t have identifiable Causes
Often have a genetic or unidentified environmental cause as:
- Genetic epilepsy syndromes
Criteria of Dx of Epilepsy
Pathophysiology of Seizures
Pathophysiology of Seizures
- Cellular Mechanism of Seizure Generation
Pathophysiology of Seizures
- The Basic Mechanism of neuranal Excitability
Action Potential
Pathophysiology of Seizures
- Hyperexcitable State may result from …..
Action potentials occur due to depolarization of the neuronal membrane, with membrane depolarization propagating down the axon to induce neurotransmitter release at the axon terminal.
..
Classification of Seizures
Def of Focal Seizures
Start in network of cells on one side of the brain
Types of Focal Seizures
Def of Generalized Seizures
Start in network of cells on both side of the brain
Types of Generalized Seizures
- Generalized Tonic-Clonic Seizures
- Absence Seizures
- Myoclonic Seizures
- Tonic Seizures
- Atonic Seizures
Awarness in Focal Aware Seizures (Simple Partial)
Awareness remains intact, even if the person is unable to talk or respond during a seizure.
Source of Focal Aware Seizures (Simple Partial)
Arise from any area of the cerebral cortex & produce a vast array
Source of Focal Aware Motor Seizures (Simple Partial)
Arising from the Motor cortex
CP of Focal Aware Motor Seizures (Simple Partial)
Source of Focal Sensory Motor Seizures (Simple Partial)
Arising from the Sensory cortex
CP of Focal Aware Sensory Seizures (Simple Partial)
Source of Focal Aware Cognitive &Emotional Seizures (Simple Partial)
Arising from the Temporal lobe
CP of Focal Aware Cognitive & Emotional Seizures (Simple Partial)
Def of Focal Impaired Awareness Seizures (Comple Partial)
Focal seizures associated with impaired awareness at any time during a seizure.
Source of Focal Impaired Awareness Seizures (Comple Partial)
Arise from the temporal lobe.
CP of Focal Impaired Awareness Seizures (Comple Partial)
Duration of Focal Impaired Awareness Seizures (Comple Partial)
0.5 - 3 min
Source of Focal to Bilateral Tonic-Clonic Seizures
Start in one side of the brain and spreads to both sides.
CP of Focal to Bilateral Tonic-Clonic Seizures
Another Name for Generalized Motor (Tonic-Clonic) Seizures “GTCS”
Grand mal epilepsy
Duration of Generalized Motor (Tonic-Clonic) Seizures “GTCS”
between 30 seconds and 2-3 minutes.
CP of Generalized Motor (Tonic-Clonic) Seizures “GTCS”
- No preceding Aura or warning
- Ictal Stages
- Post-Ictal Stages
CP of Generalized Motor (Tonic-Clonic) Seizures “GTCS”
- Aura
No preceding Aura or warning
CP of Generalized Motor (Tonic-Clonic) Seizures “GTCS”
- Ictal Stage
CP of Generalized Motor (Tonic-Clonic) Seizures “GTCS”
- Tonic Phase of Ictal Stage
CP of Generalized Motor (Tonic-Clonic) Seizures “GTCS”
- Clonic Phase of Ictal Stage
CP of Generalized Motor (Tonic-Clonic) Seizures “GTCS”
- Post-Ictal Stage
Another Name of Generalized Non-Motor (Absence) Seizures
Petit mal epilepsy
Epidemeology of Generalized Non-Motor (Absence) Seizures
Begin in childhood or adolescence
Duration of Generalized Non-Motor (Absence) Seizures
Lasts for just a few seconds
CP of Generalized Non-Motor (Absence) Seizures
Epidemeology of Myoclonic Seizures
- Occur in children, adolescents or young adults as part of “juvenile myoclonic epilepsy”.
- Occurs more on awaking up or falling asleep
CP of Myoclonic Seizures
Characterized by:
- Sudden, involuntary, brief jerks of a muscle or group of muscles.
Stimulus from Myoclonic Seizures
Provoked by fatigue or sleep deprivation.
Epidemeology of Tonic Seizures
Occur in individuals with mental retardation.
Duration of Tonic Seizures
10-20 seconds, with rapid return of consciousness or awareness.
CP of Tonic Seizures
- Sudden loss of consciousness & rigid posture of the entire body.
- They typically arise from sleep, & can occur repeatedly throughout the night.
Epidemeology of Atonic Seizures
Associated with individuals with mental retardation.
CP of Atonic Seizures
Sudden drop attacks in which the patient loses tone and falls to the ground.
DDx of Seizures
DDx of Seizures
- Syncope
What is Syncope Mostly Confused with?
Most commonly confused with GTCS
What is syncope preceded by?
lightheadedness, diaphoresis, and anxiety.
Characters of Syncope
A sudden, brief loss of consciousness that results from reduced cerebral blood flow.
What is syncope accompanied by?
Multifocal jerking movements that last for only 3-10 seconds.
Diffrentiation between syncope & Seizures
After syncope, Patients regain consciousness and coherence within a few seconds (no postictal state).
DDx of Seizures
- Migraine & TIA
What is Migraine/TIA mostly Conused With?
Simple and Complex focal seizures.
How to diffrentiate between Migraine/TIA & Seizures?
DDx of Seizures
- Movement Disorders
What are movement Disorders mostly confused with?
May be confused with motor seizures, especially myoclonus and hemiballismus
How to diffrentiate between Movement Disorders & Seizures?
- Most seizures are discrete events that Are separated in time by hours, days or months.
- Most movement disorders tend to be relatively continuous activities.
DDx of Seizures
- Sensory Symptoms
Dysfunction of the sensory end organ (e.g. eyes in patients with visual symptoms), before concluding that the problem is coming from the brain.
..
DDx of Seizures
- Sleep Disorders
DDx of Seizures
- Psychogenic Nonepileptic Seizures (Pseudo-seizures)
What are (Pseudo-seizures) mostly confused with?
Easily mistaken for epileptic seizures.
Def of (Pseudo-seizures)
- Attacks resemble seizures but secondary to psychiatric disorders “emotionally triggered attacks”
Characters of (Pseudo-seizures)
INVx for (Pseudo-seizures)
- The EEG record during the episode does not show the seizure activity “normal EEG”.
- The gold standard in diagnosis remains simultaneous video and EEG monitoring.
Approach for a person with 1st Seizure
Dx of Seizures
Dx of Seizures
- Hx & Ex
Dx of Seizures
- Labs
Dx of Seizures
- Neuroimaging
Dx of Seizures
- EEG
Significance of EEG
- Differentiate epileptic seizures from conditions that mimic them.
- Classify seizure types
- Tailor therapy.
The yield of EEG increases with ……
- Sleep deprivation
- Performing multiple studies
- Performing the study in close proximity to the seizure.
TTT of Seizures
TTT of Seizures
- TTT of Provoked Seizures
TTT of Seizures
- TTT of Unprovoked Seizures & Epilepsy
ASMs may be prescribed for patients after a first unprovoked seizure if there is:
TTT of Seizures
- General Principles in drug therapy
The choice of ASM is usually based on:
Examples of ASM
Dose & SE of Phenobarbital
Dose & SE of Phenytoin
Dose & SE of Carbamazpine
Dose & SE of Valproate
Dose & SE of Lamotrigine
Dose & SE of Gabapentine
Dose & SE of Topiramate
Dose & SE of Oxcarbazepine
Dose & SE of Levetiracetam
Dose & SE of Zonisamide
Dose & SE of lacosamide
Dose & SE of Rufinamide
Dose & SE of Esclicarbazepine
Drug of Choice
- Focal seizures and secondarily Generalized seizures
Phenytoin, Carbamazepine, Oxcarbazepine, Levetiracetam,
Lamotrigine
Drug of Choice
- Primary generalized tonic-clonic seizures
Valproate, Lamotrigine
Drug of Choice
- Abxence Seizures
Valproate, Ethosuximide
Drug of Choice
- Juvenile myoclonic epilepsy
Valproate, Levetiracetam
Drug of Choice
- Patient taking multiple medications
Levetiracetam, Lacosamide
Drug of Choice
- Medication expense is a concern
Phenytoin, Carbamazepine, Valproate
Drug of Choice
- Pregnancy
Lamotrigine, Levetiracetam (avoid valproate)
Drug of Choice
- Hepatic Failure
Levetiracetam, Topiramate, Gabapentin
Drug of Choice
- Renal Failure
Carbamazipine, Oxcarbazepine, Lamorigine
Withdrawing ASMs
Ideal candidates for medication withdrawal have:
Def of Status Epilepticus
- A single seizure lasting more than five minutes or two or more seizures between which the patient does not recover.
- It is a life-threatening medical emergency.
TTT of Status Epilepticus
TTT of Status Epilepticus
- Life Support
TTT of Status Epilepticus
- Abort Seizures
TTT of Status Epilepticus
- Abort Seizures (Phase I)
Intravenous lorazepam (0.1 mg/kg) or diazepam (0.15 mg/kg)
TTT of Status Epilepticus
- Abort Seizures (Phase II)
- Intravenous phenytoin (15-20 mg/kg)
- Valproate (25-40 mg/kg) or Levetiracetam (1000- 3000 mg)
TTT of Status Epilepticus
- Abort Seizures (Phase III)
TTT of Status Epilepticus
- Abort Seizures (Phase IV)
- Pentobarbital is loaded at a dose of 5 mg/ kg followed by IV infusion of 1-10 mg/kg/hr, titrated gradually upwards to a burst- suppression pattern on EEG
TTT of Status Epilepticus
- Determine the etiology
- Once seizure control is established, focus on determining the etiology
- History, examination, Laboratory studies, Neuroimaging and sometimes CSF examination.
TTT of Status Epilepticus
- Prevent Further Episodes
- Correct the proximate cause of status epilepticus if detected.
- Patients with known epilepsy need ASM regimen modification to prevent seizure recurrence.
