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Infantile spasms syndrome

Last reviewed: 8 Nov 2023
Last updated: 10 May 2023



History and exam

Key diagnostic factors

  • spasms
  • head nodding
  • neurodevelopmental delay or regression
More key diagnostic factors

Other diagnostic factors

  • onset age 3-12 months
  • perinatal complication
  • abnormal eye movements
  • microcephaly
  • ash-leaf macules
  • motor system abnormalities
Other diagnostic factors

Risk factors

  • brain malformation
  • neurocutaneous abnormalities
  • prenatal or perinatal vascular event
  • intrauterine or perinatal infections
  • inherited metabolic disorder
  • genetic disorders
  • family history
  • neonatal sinovenous thrombosis
  • postnatal brain injury
  • brain tumors
More risk factors

Diagnostic investigations

1st investigations to order

  • sleep electroencephalogram (EEG)
  • complete blood count
  • blood chemistries
  • plasma glucose
  • serum calcium
  • serum magnesium
  • liver function tests
  • ammonia
  • blood gas
  • plasma lactate/pyruvate
  • plasma amino acids
  • urine organic acids
  • acylcarnitines (blood spot)
  • biotinidase
  • urine alpha-amino adipic semialdehyde dehydrogenase (AASA)
  • urine and plasma creatine and guanidinoacetate
  • next-generation sequencing: gene panel/whole-exome sequencing/whole-genome sequencing
  • microarray comparative genome hybridization (CGH)
  • brain MRI
More 1st investigations to order

Investigations to consider

  • cerebrospinal fluid (CSF) exam
  • thyroid function tests (free thyroxine [FT4], thyroid-stimulating hormone [TSH])
  • plasma transferrin glycoforms
  • very long-chain fatty acids
  • serum copper, ceruloplasmin
  • urine sulfocysteine
  • CT brain
  • cytomegalovirus (CMV) culture, polymerase chain reaction (PCR), or serology
  • toxoplasmosis serology
  • echocardiogram
  • renal ultrasound
  • ophthalmology exam
More investigations to consider

Treatment algorithm


all patients



Robert Robinson, MA, MBBS, FRCP, PhD

Consultant Paediatric Neurologist

Great Ormond Street Hospital




RR declares that he has no competing interests.

Sarah Buts, MD

Clinical Fellow in Paediatric Neurology

Great Ormond Street Hospital




SB declares that she has no competing interests.


Dr Robert Robinson and Dr Sarah Buts would like to gratefully acknowledge Dr Katharina Vezyroglou, Dr Marjorie Illingworth, Dr Pradnya Gadgil, Dr Teesta Soman, and Dr Shelly Weiss, previous contributors to this topic.


KV, MI, PG, TS, and SW declare that they have no competing interests.

Peer reviewers

Gregory L. Holmes, MD

Section Chief of Neurology

Dartmouth-Hitchcock Medical Center




GLH declares that he has no competing interests.

Maria Roberta Cilio, MD, PhD

Attending Pediatric Neurologist

Division of Neurology

Bambino Gesu Children's Hospital




MRC declares that she has no competing interests.

Lionel Carmant, MD

Professor of Neurology

Department of Pediatrics

University of Montreal

Director of Epilepsy Clinic and Research Group

Saint Justine Hospital





LC declares that he has no competing interests.

  • Infantile spasms syndrome images
  • Differentials

    • Dravet syndrome
    • Benign familial infantile seizures
    • Benign sleep myoclonus
    More Differentials
  • Guidelines

    • Evidence-based guideline update: medical treatment of infantile spasms
    • Infantile spasms: a US consensus report
    More Guidelines
  • Patient leaflets

    Epilepsy: questions to ask your doctor

    More Patient leaflets
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