Infantile Spasm (West Syndrome) Clinical Presentation

Updated: Jan 11, 2019
  • Author: Tracy A Glauser, MD; Chief Editor: Stephen L Nelson, Jr, MD, PhD, FAACPDM, FAAN, FAAP, FANA  more...
  • Print


Ictal manifestations

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 of spasms may vary from a subtle head nodding to a powerful contraction of the body. Infantile spasms usually occur in clusters, often comprised of several dozen spasms, each separated by 5-30 seconds. Spasms frequently occur just before sleep or upon awakening. They can be observed during sleep, although this is rare.

Spasms can be flexor, extensor, or a mixture of flexion and extension. Flexor spasms consist of brief contractions of the flexor muscles of the neck, trunks, and limbs, resulting in a brief jerk. They may resemble a self-hugging motion and often are associated with a cry. The patient then relaxes, and the jerk repeats. These attacks occur in clusters throughout the day and last anywhere from less than 1 minute to 10-15 minutes or longer in some patients.

Extensor spasms consist of contractions of the extensor musculature, with sudden extension of the neck and trunk and with extension and abduction of the limbs. Extensor spasms and asymmetrical or unilateral spasms often are associated with symptomatic cases.

Mixed spasms are the most common type, consisting of flexion of the neck and arms and extension of the legs or of flexion of the legs and extension of the arms. In different series, the frequency of the 3 spasm types were 42-50% mixed, 34-42% flexor, and 19-23% extensor.

Interictal manifestations

An arrest or regression of psychomotor development accompanies the onset of spasms in 70-95% of patients.

Family history

A family history of infantile spasms is uncommon, but as many as 17% of patients may have a family history of any epilepsy.


Physical Examination

General physical examination

Physical examination can be important in helping to identify specific etiologies that may have a combination of systemic and neurologic symptoms (eg, tuberous sclerosis complex). However, a patient with infantile spasms often has normal findings on general physical examination, and no pathognomonic physical findings are present in patients with infantile spasms.

Patients may exhibit moderate to severe growth delay, but this is a nonspecific finding that is more a reflection of the underlying brain injury than of a specific epilepsy syndrome.

Nonetheless, if certain abnormalities in the general physical examination are noted (eg, adenoma sebaceum, ash leaf macules), specific etiologies may be suggested.

Neurologic examination

The neurologic examination in patients with infantile spasms demonstrates abnormalities in mental status function, specifically delays in developmental milestones consistent with developmental delay or regression. However, no pathognomonic findings are present on neurologic examination in patients with infantile spasms.

Abnormalities in level of consciousness, cranial nerve function, and motor/sensory/reflex examination are nonspecific findings and more a reflection of the underlying brain injury or the effect of anticonvulsant medications than of the syndrome.

Ophthalmic examination

Ophthalmic examination may reveal chorioretinitis from congenital infections, chorioretinal lacunar defects in patients with Aicardi syndrome, or retinal tubers in patients with tuberous sclerosis.

Dermatologic examination

Use a Wood lamp to examine the skin. Tuberous sclerosis is the single most common recognizable cause of infantile spasms. Therefore, a careful examination of the skin for the characteristic hypopigmented lesions of tuberous sclerosis is mandatory. The unaided bedside identification of these lesions may be more difficult in patients with a light complexion.