Symptomatic Generalized Epilepsy (SGE) Practice Flashcards

Flashcards covering the definitions, seizure types, EEG characteristics, and specific syndromes associated with Symptomatic Generalized Epilepsy (SGE).

Symptomatic Generalized Epilepsy (SGE)

A syndrome in which the epileptic seizures are the result of one or more identifiable structural lesions of the brain.

Prenatal etiologies of SGE

Causes that are genetic or extrinsic occurring before birth.

Perinatal etiologies of SGE

Causes resulting from birth trauma or anoxia.

Postnatal etiologies of SGE

Causes resulting from trauma or infection after birth.

Clonic seizure

Repetitive and rhythmic jerking ($1-2\,\text{sec}$) of limbs, neck, or face.

Tonic seizure

Symmetric or asymmetric stiffening or posturing ($5-10\,\text{sec}$).

Atonic seizure

Abrupt loss of muscle tone, usually truncal and resulting in a head drop or a fall.

Atypical absence

Seizure similar to absence seizure but longer and with less clear onset and termination.

Inter-ictal EEG in SGE

Common features include slow background, asymmetric sleep transient, multiregional slowing and epileptiform discharges, slow spike and wave, GPFA, and electrodecremental response.

Slow Spike and Wave (SSW)

EEG morphology with a frequency of $1.5 - 2.5\,\text{Hz}$ featuring spikes or sharp waves followed by a slow wave, generally not induced by hyperventilation or photic stimulation.

Generalized Paroxysmal Fast Activity (GPFA)

Bilaterally synchronous $10-25\,\text{Hz}$ activity, appearing during sleep and maximal in the anterior and vertex region.

Electrodecremental Response (ELAE)

Episodic low amplitude events characterized by sudden attenuation of background, seen in atonic and tonic seizures.

Early Myoclonic Encephalopathy

Occurs at onset $< 28\,\text{days}$ and has an erratic focal myoclonus, which can migrate throughout the infant's body.

Ohtahara Syndrome

Also known as Early infantile epileptic encephalopathy with suppression burst; tonic spasms are the dominant seizure type with little to no myoclonic seizures.

West Syndrome

Consists of the triad of infantile spasms, mental retardation, and an EEG pattern of hypsarrhythmia.

Hypsarrhythmia

An EEG pattern consisting of chaotic, high amplitude asynchronous sharp and spike wave activity.

Lennox-Gastaut Syndrome (LGS)

Consists of a triad of multiple seizure types, mental retardation, and EEG with slow diffuse spike-wave complexes less than $3\,\text{Hz}$.

Progressive Myoclonic Epilepsy

Intractable myoclonic jerks with tonic-clonic seizures secondary to metabolic and neurodegenerative conditions, often with cerebellar degeneration (ataxia, dysarthria, and tremor).