Infantile Epileptic Spasms Syndrome (West Syndrome)

Continuing Education Activity

• Reclassification: IESS reclassified to include patients not fully meeting West syndrome criteria.
• Seizure Disorder: Described by William West in 1841.
• EEG Changes: Characteristic spasms correlate with hypsarrhythmia.
• Association: Strong link with developmental delay or regression.

Objectives

• Identify etiology of infantile spasm.
• Differentiate infantile spasms from similar conditions.
• Implement evidence-based treatment strategies.
• Improve interprofessional team care coordination.

Introduction

• Disorder: Mainly affects those in their first year.
• Reclassification: IESS includes more patients than traditional West syndrome.

Etiology

• Classification: Symptomatic, cryptogenic, idiopathic.
  • Symptomatic: Identified cause, significant developmental delay.
  • Cryptogenic: No identified cause; better prognosis.
  • Idiopathic: Normal development before onset.

Prenatal Causes

• CNS malformations, neurocutaneous disorders, chromosome abnormalities, genetic mutations, inborn errors of metabolism, congenital infections.

Perinatal Causes

• Hypoxic-ischemic encephalopathy, neonatal hypoglycemia, low birth weight.

Postnatal Causes

• Traumatic injury, near drowning, tumors, CNS infections.

Epidemiology

• Incidence: 1.6 to 4.5 per 10,000 live births.
• Onset: First week of life to 4.5 years, average 3 to 7 months.

Pathophysiology

• Theories: Nonspecific brain insult, hypothalamic-pituitary-adrenal axis abnormalities, origins in cerebral hemispheres or brainstem.

History and Physical

• Age: 90% present at <1 year, peak 3-7 months.
• Spasms: Neck, trunk, extremities, flexor/extensor.
• Stages:
  1. Mild stage: Isolated spasms with regression.
  2. Severe stage: Increased frequency, clustering.
  3. Decrease in frequency, potential resolution.

Evaluation

• EEG: Full sleep-wake cycle, hypsarrhythmia pattern.
• Neuroimaging: MRI preferred, followed by PET if needed.
• Metabolic/Genetic Testing: If no obvious cause.

Treatment / Management

• Hormonal Therapy: ACTH (first line), corticotropin.
• Medications: Vigabatrin (alternative), corticosteroids.
• Diet: Ketogenic diet considered for refractory cases.
• Monitoring: Continued assessment and EEG monitoring.

Differential Diagnosis

• Includes colic, gastroesophageal reflux, benign neonatal sleep myoclonus, severe myoclonic epilepsies.

Prognosis

• Outcomes: High mortality (3%-33%), developmental disabilities.
• Better Prognosis: Cryptogenic cases, early treatment.

Complications

• Neurodevelopmental problems: eyesight, speech, hearing, motor skills, autistic traits.

Deterrence and Patient Education

• Education: Important for parents on progression, treatment options.

Enhancing Healthcare Team Outcomes

• Interprofessional Coordination: Between various healthcare professionals for effective management of infantile spasms.