Short answer · Medically reviewed summary · Last updated: 2026-05-08
West Syndrome, also known as infantile spasms, is classified under ICD-10 code G40.82 (Epileptic spasms) and was previously identified under ICD-9 code 345.6. These codes are essential for medical billing and tracking the clinical progression of West Syndrome within global health registries. What is the clinical significance of West Syndrome? West Syndrome is a rare, age-dependent epileptic encephalopathy that typically presents in infants between 3 and 12 months of age.
ICD10 code of West Syndrome and ICD9 code
ICD-10 and ICD-9 codes for West Syndrome, with classification details for clinicians, coders and patients.
West Syndrome, also known as infantile spasms, is classified under ICD-10 code G40.82 (Epileptic spasms) and was previously identified under ICD-9 code 345.6. These codes are essential for medical billing and tracking the clinical progression of West Syndrome within global health registries.
What is the clinical significance of West Syndrome?
West Syndrome is a rare, age-dependent epileptic encephalopathy that typically presents in infants between 3 and 12 months of age. Characterized by the clinical triad of epileptic spasms, hypsarrhythmia on an EEG, and developmental stagnation or regression, West Syndrome requires urgent neurological evaluation. Early intervention is critical, as the underlying cause of West Syndrome can range from genetic mutations to structural brain abnormalities or metabolic disorders.
How is West Syndrome diagnosed and coded?
Diagnosis of West Syndrome involves a combination of video-EEG monitoring to capture the characteristic spasms and brain imaging, such as an MRI, to identify potential etiologies. Clinicians use the ICD-10 code G40.82 to document West Syndrome, which helps in coordinating long-term care plans. Because West Syndrome is a medical emergency, rapid identification is the primary goal to prevent further cognitive impairment.
What are the common causes associated with West Syndrome?
The etiology of West Syndrome is highly heterogeneous. Identifying the cause is vital for prognosis and treatment selection. Common categories include:
- Structural: Brain malformations, tuberous sclerosis complex, or hypoxic-ischemic injury.
- Genetic: Mutations in genes such as CDKL5, ARX, or STXBP1.
- Metabolic: Disorders such as pyridoxine dependency or mitochondrial diseases.
- Unknown: In approximately 20-30% of cases, the specific cause of West Syndrome remains cryptogenic or idiopathic despite thorough investigation.
Next steps
- Consult a pediatric neurologist immediately if you observe clusters of sudden, brief stiffening or "jackknife" movements in your infant.
- Connect with the 7 members of our West Syndrome community at DiseaseMaps.org to share experiences and supportive resources.
- Request genetic testing and metabolic screening to determine if a specific underlying condition is triggering the West Syndrome.
- Maintain a seizure diary to track the frequency and morphology of spasms to assist your specialist in assessing treatment efficacy.
Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.
References
- NIH GARD: Genetic and Rare Diseases Information Center - West Syndrome
- Orphanet: Infantile spasms (ORPHA:909)
- OMIM: Online Mendelian Inheritance in Man - West Syndrome (Entry 308350)
- Child Neurology Foundation: Resources for Infantile Spasms
