Seizures

• A 16-year-old girl presents to the emergency department with a recent convulsive episode. The mother reports that this episode occured a few hours after awakening, described her movements as myoclonic, and involving the upper extremity. As time progressed, her myoclonus evolved into a generalized tonic-clonic seizure that lasted 3-4 minutes. The patient reported to sleeping only a few hours per night due to upcoming examinations. Physical exam is unremarkable. EEG shows 5-Hz polyspike and slow-wave discharges. (Juvenile myoclonic epilepsy)

Introduction – Seizures

• Clinical definition
  • synchronized and high-frequency neuronal depolarization that results in
    • abnormal behavior and patient experience
  • this is different from epilepsy, which can be simply described as
    • a tendency to have recurrent seizures that are unprovoked
      • febrile seizures are not considered to be epilepsy
• Other definitions
  • ictal
    • during the seizure
  • postictal
    • after the seizure
  • interictal
    • between seizures
  • aura
    • foc
    • for example, patients may describe a rising epigastric visceral sensation in
      • a seizure affecting the medial temporal limbic structures
  • status epilepticus
    • life threatening seizure episode that occurs
      • continuously or in rapid successions
• Etiology
  • can be divided into provoked and unprovoked causes
    • provoked
      • substance abuse (e.g., cocaine and MDMA)
      • space occupying lesion (e.g., malignancy and abscess)
      • stroke (e.g., ischemic and hemorrhagic)
      • meningitis and encephalitis
      • hypo- or hyperglycemia
      • hyponatremia
      • hypocalcemia
      • hypomagnesemia
      • medication withdrawal (e.g., benzodiazepine and alcohol)
    • unprovoked
      • underlying neurological disorder (e.g., childhood absence epilepsy and neurofibromatosis)
• Seizure classification
  • classification is based on the International League Against Epilepsy (ILAE)
  • seizures can be initially divided into
• focal and generalized

Focal Seizures

• Clinical definition 
  • abnormal neuronal activity in a localized (focal) part of the brain
• Partial seizures can
  • secondarily generalize
  • be subdivided into
    • simple partial seizures
    • complex partial seizures

Focal Seizure Types
Seizure Type	Clinical Features
Focal onset seizures with awareness	Consciousness is sparedSymptoms are dependent on the anatomical location of the seizuree.g., abnormal shapes or flashes when there is a seizure in the primary visual cortexTypically no postictal deficits in brief simple partial seizures
Focal onset seizures without awareness	Consciousness is impairedthis can be complete or mildSymptoms are dependent on the anatomical location of the seizureMay have automatismsMost common location is in thetemporal lobes

Generalized Seizures

• Clinical definition
  • abnormal neuronal activity in both hemispheres of the brain
• Generalized seizures
  • is almost always associated with impaired consciousness
  • generalized tonic-clonic (grand mal) seizures is
    • the most common type of generalized seizure

Generalized Seizure Types
Seizure Type	Clinical Features
Absence (petit mal seizures)	Most commonly occurs in childrenCan occur many times in a dayBrief episodes (~10 seconds) of unresponsivenessparents may report the patient had a blank starecan occur many times in a dayNo postictal deficits and automatismsCharacteristic EEG finding isgeneralized 3-4-Hz spike and wave discharges
Myoclonic	Patients can present with quick and repetitive jerks
Tonic-clonic	Typically begins with a tonic phasecontraction of all muscles for 10-15 secondsleads to a fall “like a tree”The clonic phase follows the tonic phaserhythmic jerking of the bilateral extremitiesThere are postictal deficits
Tonic	Patients can present with stiffening
Atonic	Patients can present with “drop” seizurescan be mistaken as fainting

Febrile Seizures

• Seen in pediatric patients with fever temperatures exceeding 38°C with no other seizure-provoking etiology
• Categories
  • simple: generalized, do not last longer than 15 minutes, and no recurrence within 24 hours.
  • complex: focal, do last longer than 15 minutes, and/or recurrence within 24 hours.
• Treatment
  • Supportive 

Studies

1. Causes: Seizures can be caused by a variety of factors, including genetics, brain injury, infection, and metabolic imbalances. In some cases, the cause is unknown.
2. Diagnosis: Seizures can be diagnosed through a combination of medical history, physical examination, and diagnostic tests such as EEG (electroencephalogram) and MRI (magnetic resonance imaging).
3. Treatment: Treatment for seizures often involves medications, such as antiepileptic drugs (AEDs), and lifestyle changes, such as getting enough sleep and avoiding triggers that can induce seizures. In some cases, surgery may be necessary to remove the portion of the brain causing the seizures.
4. Comorbidities: Seizures are often associated with other neurological conditions, such as epilepsy, migraine, and multiple sclerosis. They can also be associated with psychiatric disorders, such as anxiety and depression.
5. New treatments: There is ongoing research into new treatments, including non-invasive brain stimulation techniques such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS).
6. Epilepsy surgery: Recent studies have shown that epilepsy surgery can be a highly effective treatment for patients with drug-resistant epilepsy, resulting in seizure freedom in up to 80% of cases.

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