Seizures and epilepsy

Seizure

Seizure: Sudden behavioral changes resulting from abnormal electrical discharges from brain cells. It is a "symptom" that can be provoked (Provoked Seizure) or occur without a specific trigger (unprovoked seizure).

Epilepsy:

1. Recurrence of unprovoked seizures more than twice, separated by more than 24 hours.
2. A single occurrence of an unprovoked seizure with a future risk of seizures greater than 60% in the general population, due to factors like remote stroke, CNS infection, or traumatic brain injury.
3. Seizure characteristics and EEG findings consistent with an epileptic syndrome, regardless of the number of occurrences.

Approach to Seizure

Step 1: True Seizure or not?

Seizure phases: Preictal, Ictal, and Postictal.

• Preictal Phase: Auras often occur, such as seeing flashing lights, feeling chest tightness, hearing unusual sounds, or experiencing mood changes.
• Ictal: Seizure characteristics depend on the location of the pathology in the brain, uncontrollable by the patient, typically lasting 1-2 minutes.
• Postictal phase: Drowsiness, weakness, headache, confusion.
• Precipitating factors: physical stress, mental stress, sleep deprivation.
• Differential diagnosis (Ddx): Syncope, TIA, Hypoglycemia (which can also cause seizures), Migraine, Sleep disorder, Stroke.

If a seizure event is captured, usually seizures stop within 1-2 minutes. If it exceeds 5 minutes, start management for status epilepticus.

Step 2: Provoked or Unprovoked seizure

• Provoked seizure (Acute symptomatic seizure): Head injury, stroke, CNS infection, post intracranial surgery, toxins (lead, organophosphate), metabolic disturbance, fever (in children).
• Unprovoked seizure indicates brain epileptogenicity:
• Remote Symptomatic seizure: Head injury, stroke > 1 week later, post encephalopathy, sequelae of CNS infection.
• Progressive Symptomatic seizure: Brain tumor, autoimmune (cerebral lupus, multiple sclerosis).

Step 3: Classification of Epilepsy (ILAE 2017)

3.1 Seizure Type:

• Focal Onset: Begins at a pathology in one hemisphere of the brain. If focal, it must be specified whether there's content of consciousness, reported as Impaired awareness or Preserved awareness.
• Generalized Onset: Begins at pathologies in both hemispheres of the brain simultaneously.
• Unknown Onset: No EEG or Video results available.

Critical Blood Component Values Indicating Seizure Risk from Metabolic Disorders:

• Serum Glucose: Dangerously low (< 36 mg/dL) or high (> 450 mg/dL) levels.
• Serum Sodium: Very low (< 115 mg/dL) can cause seizures.
• Serum Calcium: Extremely low (< 5.0 mg/dL) may lead to seizures.
• Serum Magnesium: Low (< 0.8 mg/dL) is associated with seizures.
• BUN: High (> 100 mg/dL) indicates potential kidney issues and seizures.
• Creatinine: High levels (> 10 mg/dL) suggest severe kidney dysfunction, possibly resulting in seizures.

3.2 Type of Epilepsies: Divided by onset into Focal, Generalized, Combined, and Unknown. The next step is to identify the etiology including Structural, Genetic, Infectious, Metabolic, Immune, and Unknown.

Investigations for Epilepsy Due to Etiology:

• EEG: Recommended for all new onset seizure cases, conducted within 24 hours after a seizure to increase the chance of detecting abnormalities by 20%.
• Imaging: For unclear cases or stroke conditions, MRI is preferred over others.
• For the 1st episode of seizure due to precipitating factors:
• EEG: Conducted for all cases if possible.
• Imaging: MRI or CT brain.

Indications for CT Brain:

• Age over 40.
• Focal onset seizure.
• Persistently altered mental status postictally.
• Fever.
• Recent trauma history.
• Persistent postictal headache.
• Cancer history.
• Anticoagulation history.
• Immunodeficiency.
• Focal deficits on examination.

Lab Tests (based on suspected conditions): Blood sugar, electrolytes, CBC, CSF studies (in case of fever), toxicology screening.

Step 4: management of a first episode of unprovoked seizure and status epilepticus involves a comprehensive approach that includes risk assessment, drug therapy, seizure precautions, and specific management protocols for status epilepticus. Here’s an overview based on the provided information:

1st Episode of Unprovoked Seizure:

• Indications for Anti-Epileptic Drugs (AEDs): Initiation of AED therapy is considered in the presence of strong predictors for recurrence, which include status epilepticus, high-risk occupations (e.g., driving, flying), and conditions posing a risk of severe injury (e.g., osteoporosis, coagulopathy).
• Seizure Precautions: It's recommended to avoid triggers such as insufficient sleep and alcohol consumption. High-risk activities, such as swimming alone, working at heights, or operating machinery, should be approached with caution. Driving restrictions are typically advised for a period following a seizure.

Generalized Convulsive Status Epilepticus (GCSE):

• Definition: GCSE is defined as continuous seizure activity lasting more than 30 minutes or multiple seizures without full recovery of consciousness between them within 30 minutes.
• Practical Approach: Treatment for status epilepticus is initiated if seizure activity exceeds 5 minutes due to the likelihood of ongoing seizures and potential for neuronal injury.

Management of Status Epilepticus:

Based on the 2012 guidelines for the evaluation and management of status epilepticus, the management timeline is as follows:

• Rapid Assessment and Support:
• Assess and manage airway, breathing, circulation, and disability (ABCD, prioritizing CAB-D).
• Check blood glucose or toxic/metabolic workup.
• Consider intubation based on respiratory status and arterial blood gas (ABG) results.
• Secure two IV accesses for medication administration.
• Continuous monitoring of vital signs, pulse oximetry, and IV access.
• Initial Pharmacologic Therapy:
• First IV: Diazepam (Valium) 10 mg IV (0.15 mg/kg/dose, max dose 10 mg/dose), with a possible repeat dose in 3-5 minutes.
• Second IV: Phenytoin (Dilantin) with a loading dose of 20 mg/kg plus NSS 100 ml, then 25-50 mg/min, while monitoring for adverse effects.
• If IV access is not available, consider Midazolam IM or Buccal administration, with dosages adjusted for body weight.
• Refractory Status Epilepticus:
• Intubation may be necessary for prolonged seizures without consciousness recovery, with possible admission to the ICU and consideration of EEG monitoring.
• General anesthetic drugs may be considered in refractory cases.

This comprehensive management plan aims to rapidly control seizure activity, prevent recurrence, and minimize the risk of complications.