2. Overview
• Severe epilepsy syndrome composed of the triad of
infantile spasms, an interictal EEG pattern termed
hypsarrhythmia, and mental retardation.
• Dr W J West, gave the first detailed description of
infantile spasms.
• Published in The Lancet in 1841.
• Generalized Flexion Epilepsy, Infantile Epileptic
Encephalopathy, Infantile Myoclonic Encephalopathy,
jackknife convulsions, Massive Myoclonia , Salaam
spasms.
3. • Reflect abnormal interactions between the cortex and
brainstem structures.
• Insult to the immature CNS.
• Brain-adrenal axis.
• stressors in the immature brain produces an abnormal, excessive
secretion of corticotropin-releasing hormone (CRH), causing
spasms.
• Based on etiology classified in to
• Symptomatic
• Cryptogenic
• idiopathic.
4. • Two specific genetic defects have a phenotypic
presentation similar to that of the early onset of infantile
spasms.
• gene ARX mutation
• cyclin-dependent kinase-like protein 5 (CDKL5) mutation
• 2% of childhood epilepsies, 25% of epilepsy with onset in
the first year of life.
• Males are affected slightly more then females.
• Onset is before 12 mo of age.
• Peak onset between 4 to 6 mo.
5. • Only 14% of infants with symptomatic West syndrome
have normal or borderline-normal cognitive development.
• 50-70% of patients develop other seizure types.
• 18-50% of patients will develop Lennox-Gastaut
syndrome or some other form of symptomatic generalized
epilepsy.
• 70% dies before 20 yrs of age.
7. • Chaotic, high- to extremely high–voltage, polymorphic
delta and theta rhythms with superimposed multifocal
spikes and wave discharges.
• Gibbs and Gibbs described hypsarrhythmia in 1952.
• Unilateral hypsarrhythmia and asymmetrical ictal EEG
changes during spasms are correlated with focal or
asymmetrical cerebral lesions on imaging studies.
• Hypsarrhythmia either disappears or improves during a
cluster of spasms and/or REM sleep.
• Hypsarrhythmia rarely persists beyond the age of 24
months.
8. Defining characteristics(Gibs and Gibs):
• Essentially continuous
• Present in both awake and sleep
• Consist of random high voltage slow waves and spikes.
• Spikes vary in location and duration – focal or multifocal
• Occasionally generalized discharges but never in a
rhythmic or highly organized pattern.
9. • Five variants of the "classical" hypsarrhythmic pattern
have been identified.
• Hypsarrhythmia with increased interhemispheric
synchronization (35%).
• Asymmetric hypsarrhythmia (12%).
• Hypsarrhythmia with a consistent focus of abnormal
discharge (26%).
• Hypsarrhythmia with episodes of voltage attenuation
(11%).
• Hypsarrhythmia without spike or sharp activity (7%).
14. Factors influencing Hypsarrhythmia
pattern:
• It is a highly dynamic pattern:
• Sleep:
• NREM – increase in amplitude of waves, grouping of spikes,
sharps and slow waves, sometimes attenuation.
• REM: complete to near complete disappearance of hypsarrhythmia
pattern.
• Normalization can also be seen upon waking up.
• Ictal events:
• After a seizure episode there can be transient periods of decreased
abnormal activity and normalization of background.
• Evolution with time:
• Hypsarrhythmia pattern tends to decrease with time and
disappears by 5 to 7 years.
15. Precursors of hypsarrhythmia:
• Focal or multifocal spikes
• B/L parieto temporal dominant spikes
• Burst suppression pattern.
16. Significance of interictal pattern:
• Diagnostic value: very strong indicator of infantile spasms.
• Correlation with etiology:
• Asymmetric and focal findings correlate with a symptomatic
etiology.
• Hemi hypsarrhythmia pattern seen in cerebral dysgenesis
• HIE- absence of sleep pattern.
• Correlation with outcome:
17. ICTAL PATTERNS:
• Kellaway et al.
• Described 11 different patterns.
• High amplitude fast activity is the most commonest.
• Asymmetry indicates possible symptomatic etiology.
18. • Infantile Spasms: Diagnosis, Management and
Prognosis
• James D. Frost Jr., Richard A. Hrachovy - 2003
