Understanding Seizures and Status Epilepticus

Definition of Seizure

• A seizure is a transient occurrence of signs and/or symptoms from abnormal, excessive, or synchronous neuronal activity in the brain, often described as an "electrical storm."
• Convulsions refer to the motor act associated with seizures.

Status Epilepticus (SE)

• SE is defined as continuous convulsions lasting more than 5 minutes or serial convulsions with no return of consciousness between them.
• Criteria for SE varies:
  • Generalized tonic-clonic seizures: > 5 minutes
  • Focal seizures with impaired awareness: > 10 minutes
  • Absence seizures: 10-15 minutes.

Types of Seizures

• Acute Symptomatic Seizures: Provoked by immediate factors like electrolyte imbalance; often good prognosis but may signal severe brain issues.
• Unprovoked Seizures: Not linked to an acute issue; first unprovoked seizure has a 30% chance of progressing to epilepsy.
• Remote Symptomatic Seizures: Related to past brain injuries, such as old strokes.
• Reflex Seizures: Triggered by specific stimuli (e.g., flickering lights).

Classification of Epilepsy

• Epilepsy is diagnosed after two or more unprovoked seizures occurring more than 24 hours apart or by one unprovoked seizure if EEG confirms predisposition.
• Epileptic syndromes are classified by specific seizure types, age of onset, EEG findings, and prognosis.

Epileptic Encephalopathy

• Severe EEG abnormalities result in cognitive and developmental impairments.
• Developmental Epileptic Encephalopathy: Both the EEG abnormalities and genetic factors contribute to developmental delays.

Diagnosis and Classification

• ILAE classification involves multiple levels: determining if an event was a seizure, identifying the type of epilepsy, fitting it into a syndrome, and establishing a comprehensive diagnosis.
• Etiology of seizures includes genetic, structural, metabolic, immune, infectious, and undefined origins.
• Comorbidities like developmental delays and psychiatric disorders should be considered.

Types of Epileptic Syndromes

• Genetic Epilepsies: Linked to specific genetic defects; includes childhood absence epilepsy and Dravet syndrome.
• Metabolic Epilepsy: Caused by metabolic disturbances.
• Structural Epilepsy: Resulting from identifiable brain structural issues.
• Immune-mediated Epilepsy: A consequence of inflammation in the CNS treatable with immunotherapies.
• Infectious Epilepsy: Relating to chronic infections rather than acute ones.

Seizure Types and Clinical Features

• Seizure classification involves examining age of onset, seizures' characteristics, and EEG results, which assist in prognosis and treatment.
• Types include:
  • Partial Seizures: Simple (consciousness retained) and complex (impaired consciousness).
  • Generalized Seizures: Affect both hemispheres of the brain.

Generalized Tonic-Clonic Seizures

• Often presents suddenly with loss of consciousness; includes a tonic phase followed by a clonic phase.
• Postictally, patients remain semicomatosely in deep sleep, often with headaches and vomiting.

Myoclonic Epilepsies of Childhood

• Characterized by brief, symmetric muscle contractions; may result in fall or slumping forward.
• Can vary from benign in childhood to serious in adults.

Laboratory Tests for Seizures

• Essential tests include serum electrolytes, toxicology screening, metabolic testing, glucose levels, EEG, lumbar puncture, skull X-ray, and neuroimaging (preferably MRI).

Indications for Brain Imaging

• Urgent CT or MRI is necessary for focal seizures, postictal deficits, lack of return to baseline, trauma before seizures, or high-risk medical histories.

This quiz covers the definition of seizures, types, and the critical condition of status epilepticus. It explores the classifications and criteria for different seizure types, offering insights into the neurological implications and prognosis associated with each. Test your knowledge on the transient electrical disturbances in the brain.