Neurology · MU Sofia

63. Epilepsy: classification, etiology, pathogenesis, clinical features

Covers epilepsy as a recurrent unprovoked seizure disorder, then walks through its etiology grouped into idiopathic, structural and metabolic causes. It explains the excitatory-inhibitory imbalance behind neuronal hyperexcitability, sets out focal and generalised seizure types with their subtypes, and describes aura, ictal and postictal features, normal interictal examination, and complications including status epilepticus and SUDEP.

Inside: 1 section · 16 flashcards · 2 min

Topic 63 of 88 in the MU Sofia syllabus for Neurology (Medicine, Year 4). The free AceMed note covers it in 1 section, about 265 words (2 min of reading), with 16 flashcards.

In this note

  1. Epilepsy - classification, etiology, pathogenesis, clinical features

Epilepsy - classification, etiology, pathogenesis, clinical features

Definition: Epilepsy is a chronic neurological disorder characterized by a predisposition to recurrent unprovoked seizures caused by abnormal, excessive, synchronous neuronal activity in the brain.

Etiology

1.Idiopathic (Genetic): No structural brain lesion. Genetic predisposition

2.Structural/Acquired: Stroke. Brain tumors. Head trauma. CNS infections. Congenital malformations

3.Metabolic Causes: Hypoglycemia. Electrolyte disturbances. Uremia

Pathogenesis

Imbalance between:

  • Excitatory neurotransmission (glutamate ↑)
  • Inhibitory neurotransmission (GABA ↓)

Leads to neuronal hyperexcitability and hypersynchronization → seizure.

Classification of Seizures

1. Focal (Partial) Seizures: Originate in one cerebral hemisphere.

A. Focal Aware Seizure: Consciousness preserved. Motor, sensory, autonomic, or psychic symptoms

B. Focal Impaired Awareness Seizure: Altered consciousness

  • Automatisms: Lip smacking. Chewing. Picking movements

C. Focal to Bilateral Tonic-Clonic Seizure: Starts focally → spreads to both hemispheres

2. Generalized Seizures: Involve both hemispheres from onset.

A. Tonic-Clonic (Grand Mal): Most important type.

  • Tonic Phase: Loss of consciousness. Generalized muscle contraction
  • Clonic Phase: Rhythmic jerking movements.
  • Postictal Phase: Confusion. Drowsiness. Headache

B. Absence Seizure (Petit Mal): Brief loss of awareness (5–20 sec). Staring spell. No postictal confusion

C. Myoclonic Seizure: Sudden brief muscle jerks

D. Tonic Seizure: Sustained muscle contraction

E. Clonic Seizure: Repetitive jerking

F. Atonic Seizure: Sudden loss of muscle tone ("drop attacks")

Clinical Features

Before Seizure (Aura)

  • Common in focal epilepsy: Strange smell. Visual phenomena. Déjà vu sensation. Epigastric rising sensation

During Seizure: Loss of consciousness (generalized seizures). Convulsions. Tongue biting. Urinary incontinence

After Seizure (Postictal State): Confusion. Fatigue. Headache. Temporary neurological deficit (Todd's paralysis)

Examination: Usually normal between seizures unless there is an underlying neurological disease.

Complications: Trauma and injuries. Status epilepticus. Cognitive impairment. Sudden unexpected death in epilepsy (SUDEP)

Read the full note free

The whole note is free with an AceMed account, with its 16 flashcards. Premium adds flashcard recall, highlights and Ask AI.

Start freeAlready a member? Open the note