Seizures and Epilepsy

Introduction

Welcome to the comprehensive MCCQE1 preparation guide on Seizures and Epilepsy. This resource is tailored for Canadian medical students preparing for the Medical Council of Canada Qualifying Examination Part I (MCCQE1). We'll cover key concepts, Canadian guidelines, and provide practice questions to help you succeed in your exam and future medical practice in Canada.

Definitions and Classification

Seizure

A seizure is a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

Epilepsy

Epilepsy is a brain disorder characterized by an enduring predisposition to generate epileptic seizures and by the neurobiological, cognitive, psychological, and social consequences of this condition.

Classification of Seizures

Epidemiology in Canada

Understanding the epidemiology of epilepsy in Canada is crucial for MCCQE1 preparation and future practice:

• Prevalence: Approximately 1% of the Canadian population has epilepsy
• Incidence: 15,500 new cases diagnosed annually in Canada
• Age distribution: Highest incidence in young children and older adults (>65 years)
• Gender: Slightly higher prevalence in males

Etiology

Understanding the causes of seizures and epilepsy is essential for MCCQE1 success. Remember the mnemonic "VITAMINS" for common causes:

• Vascular (stroke, AVM)
• Infection (meningitis, encephalitis)
• Trauma (head injury)
• Autoimmune (limbic encephalitis)
• Metabolic (electrolyte imbalances, hypoglycemia)
• Idiopathic/genetic
• Neoplasm (brain tumors)
• Structural (cortical dysplasia, hippocampal sclerosis)

Clinical Presentation

For MCCQE1 preparation, focus on recognizing the various presentations of seizures:

1. Focal Aware Seizures (Simple Partial)

   • Preserved consciousness
   • Motor, sensory, autonomic, or psychic symptoms

2. Focal Impaired Awareness Seizures (Complex Partial)

   • Altered consciousness
   • Automatisms (e.g., lip-smacking, picking at clothes)

3. Generalized Tonic-Clonic Seizures

   • Loss of consciousness
   • Tonic phase followed by clonic phase
   • Post-ictal confusion

4. Absence Seizures

   • Brief lapses in awareness
   • May have subtle motor symptoms (e.g., eye blinking)

5. Status Epilepticus

   • Prolonged seizure or recurrent seizures without full recovery between episodes
   • Medical emergency requiring prompt intervention

Diagnostic Approach

Management

Acute Management

For the MCCQE1 exam, remember the "ABCs" of seizure management:

1. Airway: Ensure patency, protect from injury
2. Breathing: Provide oxygen if needed
3. Circulation: Establish IV access
4. Drugs: Administer antiepileptic drugs (AEDs) if indicated

Chronic Management

Canadian Guidelines

The Canadian League Against Epilepsy (CLAE) provides guidelines for the management of epilepsy in Canada. Key points for MCCQE1 preparation include:

1. First unprovoked seizure management
2. Neuroimaging in adult epilepsy
3. Transition of epilepsy care from pediatric to adult healthcare systems
4. Women with epilepsy and pregnancy

Key Points to Remember for MCCQE1

• Understand the definition and classification of seizures and epilepsy
• Know the epidemiology of epilepsy in Canada
• Memorize the "VITAMINS" mnemonic for seizure etiology
• Recognize different seizure types and their clinical presentations
• Be familiar with the diagnostic approach, including EEG and neuroimaging
• Know the acute management of seizures, including status epilepticus
• Understand the first-line and second-line AEDs used in Canada
• Be aware of non-pharmacological treatment options
• Familiarize yourself with Canadian-specific guidelines from CLAE

Sample Question

A 25-year-old woman presents to the emergency department after experiencing her first generalized tonic-clonic seizure. She has no significant medical history and is not taking any medications. Her physical examination, including neurological assessment, is normal. Laboratory tests, including electrolytes and glucose, are within normal limits. Which one of the following is the most appropriate next step in management?

• A. Start carbamazepine
• B. Perform an urgent EEG
• C. Admit for observation
• D. Arrange outpatient neurology follow-up
• E. Start levetiracetam

Explanation

The correct answer is:

• D. Arrange outpatient neurology follow-up

Explanation: For a first unprovoked seizure in an adult with normal physical examination and laboratory tests, the most appropriate next step is to arrange outpatient neurology follow-up. According to Canadian guidelines, not all patients require immediate admission or urgent EEG after a first seizure. Starting antiepileptic drugs (options A and E) is not recommended after a single unprovoked seizure, as the risk of recurrence does not outweigh the potential side effects of long-term medication. An EEG should be performed, but it doesn't need to be done urgently in the emergency department (option B). Admission for observation (option C) is not necessary for a patient who has returned to baseline and has no concerning features on examination or initial workup.

References

1. Epilepsy Canada. (2021). Facts about Epilepsy. Retrieved from https://www.epilepsy.ca/facts-about-epilepsy.html (opens in a new tab)

2. Tellez-Zenteno, J. F., Pondal-Sordo, M., Matijevic, S., & Wiebe, S. (2004). National and regional prevalence of self-reported epilepsy in Canada. Epilepsia, 45(12), 1623-1629.

3. Jetté, N., Reid, A. Y., & Wiebe, S. (2014). Surgical management of epilepsy. Canadian Medical Association Journal, 186(13), 997-1004.

4. Epilepsy Ontario. (2021). Types of Seizures. Retrieved from https://epilepsyontario.org/about-epilepsy/types-of-seizures/ (opens in a new tab)

5. Canadian League Against Epilepsy. (2021). Guidelines. Retrieved from https://claegroup.org/guidelines (opens in a new tab)

6. Kwan, P., & Brodie, M. J. (2000). Early identification of refractory epilepsy. New England Journal of Medicine, 342(5), 314-319.

7. Fisher, R. S., Acevedo, C., Arzimanoglou, A., Bogacz, A., Cross, J. H., Elger, C. E., ... & Wiebe, S. (2014). ILAE official report: a practical clinical definition of epilepsy. Epilepsia, 55(4), 475-482.