- Infantile spasms, also known as West syndrome, is a specific type of epilepsy seen in infants characterized by infantile spasms, hypsarrhythmia on EEG, and developmental regression or delay. - It represents 2% of epilepsies and typically presents between 4-6 months of age. The condition was first described in 1841 and involves sudden flexion or extension of the trunk and limbs. - Evaluation involves neurological exam, imaging (often MRI), metabolic testing, and characteristic EEG findings of hypsarrhythmia. Treatment aims to stop spasms and normalize EEG typically within 2-4 weeks using ACTH/steroids as first line. Prognosis depends on

1. WEST SYNDROME &
INFANTILE SPASMS
MITCHELL P. CREED, MD, MA
PEDIATRIC NEUROLOGY
STONY BROOK UNIVERSITY CHILDREN’S HOSPITAL

2. INFANTILE SPASMS
• Represents 2% of all epilepsies.
• 25 % of all that present in the first year of life
• 90% start before the age of 12 months.
• Peak at 4-6 months.

3. WEST SYNDROME
Triad of
• infantile spasms,
• an interictal EEG pattern termed
hypsarrhythmia,
• Development delay or regression

4. DO YOU KNOW WHO DESCRIBED FOR
THE FIRST TIME?
• West described the events in 1841as “bobbings” that
“cause a complete heaving of the head forward towards
his knees, and then immediately relaxing into the
upright position …

5. DO YOU KNOW WHO DESCRIBED FOR
THE FIRST TIME?
• … these bowings and relaxings would be repeated
alternately at intervals of a few seconds, and repeated
from 10 to 20 or more times at each attack, which attack
would not continue more than 2 or 3 minutes; he
sometimes has 2, 3 or more attacks in the day.”

6. INFANTILE SPASMS
• Spasms begin with a sudden, rapid, tonic
contraction of trunk and limb musculature that
gradually relaxes over 0.5-2 seconds.
• Contractions can last 5-10 seconds.
• The intensity may vary from a subtle head
nodding to a powerful contraction of the body.

7. • https://www.healthychildren.org/English/healt
h-issues/conditions/seizures/Pages/Infantile-
Spasms-What-Parents-Need-to-Know.aspx

8. INFANTILE SPASMS
• Infantile spasms usually occur in clusters,
often several dozens, separated by 5-30
seconds.
• Spasms frequently occur just before sleep or
upon awakening. They can be observed during
sleep, although this is rare.

9. INFANTILE SPASMS
• Spasms, the seizure type, may have
variable features
• Three subtypes (flexor, extensor, and
mixed flexor-extensor) based on postural
manifestations and patterns of muscle
involvement during the seizure.
• Flexor spasms involve flexion of the neck,
trunk, and extremities, resulting in jack-
knifing at the waist and a self-hugging
motion of the arms..

10. INFANTILE SPASMS
• Extensor spasms consist of extension of the
neck, trunk, and extremities. Mixed flexor-
extensor spasms involve combinations of the
above.

11. INTERICTAL MANIFESTATIONS
• Arrest or regression in psychomotor
development in 70-95% of patients.

12. FAMILY HISTORY

13. FAMILY HISTORY
• Only in 17 % of patients
• 10% have Hx of febrile Seizure
• Incidence 1.6-4.5/10,000 live births (2000-
2500 new cases/year in US)

14. PHYSICAL EXAMINATION
• What do you expect to
find?

15. PHYSICAL EXAMINATION
• Often Normal findings.
• Use a Wood lamp to examine the skin.
• Signs of growth delay.

16. NEUROLOGICAL EVALUATION
• Developmental Delay or regression
• No pathonomic findings

17. CLASSIFICATION
• How do you classify?

18. CLASSIFICATION
• Symptomatic
• Cryptogenic
• Idiopathic

19. ETIOLOGY
• Infantile spasms are a SYMPTOM, not an underlying
condition
• Any disorder that can produce brain damage can
be associated with infantile spasms.
• Prenatal
• Perinatal.
• Postnatal.

20. ETIOLOGY
• Genetic Syndromes: Tuberous sclerosis, Down’s
syndrome, Aicardi’s syndrome, Incontinentia
pigmenti, NF, Sturge Weber, GLUT-1 deficiency.
• Malformation syndromes: schizencephaly,
pachygyria, microgyria, etc.

21. ETIOLOGY
• Infectious: Congenital infections, meningitis,
encephalitis, brain abscess.
• Hypoxic-Ischemic or hemorrhagic insult
• Trauma
• Tumor

22. ETIOLOGY
Metabolic Disorders
Nonketotic hyperglycinemia, PKU, Maple Syrup
Urine Disease and other amino and organic
acidopathies,
Pyridoxine deficiency and dependency,
Mitochondrial encephalopathies,
Degenerative diseases.

23. INFANTILE SPASMS
• Pt must be evaluated for
Tuberous sclerosis
• Manifestation of TS are:
• Cardiac tumors
• kidney tumors
• cutaneous malformations
such as ash-leaf
hypopigmented lesions
• seizures

24. INFANTILE SPASMS
Cryptogenic
• Patients have cryptogenic infantile spasms if
developmental delay and no cause is identified
but a cause is suspected and the epilepsy is
presumed to be symptomatic.
• Account for 8-42% of the cases (wide range)

25. CLASSIFICATION
Idiopathic
• Normal psychomotor development prior to the onset of
symptoms
• Does NOT meet West Syndrome criteria
• No underlying disorders or definite causes are present
• No neurological or neuroradiological abnormalities .

26. DIFFERENTIAL DIAGNOSIS
• Benign myoclonus in infancy,
which consists of clusters of nonepileptic spasms and a
normal EEG, occurs in infants with normal psychomotor
development.
• Hyperplexia,
a startle jerk, is triggered by touching the nose and eventually
the upper limbs.
• Tonic seizures
• Shuddering
• Sandifer syndrome,
due to GE reflux, may be difficult to detect and mimic
infantile spasms.

27. DIFFERENTIAL DIAGNOSIS
• Early breath-holding spells and aversive reactions
to stimuli can result in dystonic postures or jerks.
• Jactatio capitis,
or head banging, occurs in older infants on falling
asleep.
• Spasmus nutans associated with neck tilt and
nystagmus.
• Moro reflex must be distinguished from IS

28. LAB STUDIES
• CBC diff , LFTs , renal panel with electrolytes
and glucose, calcium, magnesium,
phosphorus, and urinalysis with microscopic
examination
• Metabolic workup including glucose, liver
panel, serum lactate and pyruvate, plasma
ammonia, serum and urine amino acids, urine
organic acids, and serum biotinidase

29. LAB STUDIES
• Blood, urine, and cerebrospinal fluid cultures if
an infection is suspected
• Cerebrospinal fluid analysis for cell count,
glucose, protein, bacterial and viral culture,
lactate, pyruvate, and amino acids

30. NEUROIMAGING
• 70-80% of patients have abnormal findings on
neuroimaging studies.
• MRI more sensitive than CT scan of the brain.
• Imaging studies should be obtained prior to
starting ACTH or steroid therapy, as these
therapies are associated with the appearance
of apparent brain atrophy as treatment
continues.

31. INFANTILE SPASMS
• EEG
• Video EEG

32. EEG
Overview

34. Too
Much
Too
Little
Seizures:

35. Symmetry: Good Synchrony: Bad

36. What about EEG findings of
Infantile Spasms?

37. ICTAL EEG
• High-voltage, frontal dominant, generalized
slow-wave transient followed by voltage
attenuation, also termed an
electrodecremental episode

38. WHAT IS HYPSARRHYTMIA?
• Chaotic, high- to extremely high-voltage
polymorphic delta and theta rhythms with
• Superimposed multifocal spikes and wave
discharges

41. HYPSARRHYTHMIA
• At onset usually only during drowsiness and
light sleep.
• EEG may be normal (modified hypsarrhythmia).

42. TREATMENT

43. GOAL OF TREATMENT
• Cessation of spasms & resolution of
hypsarrhythmia in 2-4 weeks
• Quality of life with no seizures
• Fewest adverse effects from treatment
• The least number of medications.

44. TREATMENT
• First-line treatments (ie, ACTH, prednisone,
vigabatrin, pyridoxine [vitamin B-6])
• USA  natural, porcine ACTH (ACTHAR) -- $$$$$$
• Europe  tetracosactide, synthetic -- $
• Second-line treatments (ie, benzodiazepines,
valproic acid, lamotrigine, topiramate,
zonisamide)
• Combo?

45. TREATMENT
• Most of the patients achieve control within 2
weeks.

46. TREATMENT
• Focal cortical resection
• In some patients, resection
of a localized region can
lead to freedom from
seizures.
• Ketogenic Diet

47. COMPLICATIONS OF TX
• Hypertension, metabolic abnormalities, severe
irritability, osteoporosis, sepsis, and
congestive heart failure

48. PROGNOSIS
• Only 14% have normal or borderline normal
cognitive development
• Drastically improves if*:
• Treatment started within 1 month
• Developmentally normal at onset (idiopathic)
• No cause found (cryptogenic/idiopathic)
• Some associations may have better outcome,
such as Down Syndrome, NF.
*Kivity S et al. Epilepsia 2004;

49. PROGNOSIS
• Poor prognosis
Persistently abnormal EEG
Poor response to ACTH
Delayed initiation of treatment.
• 20-25% evolves to LGS

50. THE END