Infantile Spasms

Infantile spasm (IS) is a rare seizure disorder of infancy and early childhood. The onset is predominantly in the first 6 months of life.

Characteristic features of IS, sometimes called West syndrome, include myoclonic seizures, hypsarrhythmia (abnormal, chaotic electroencephalogram), and mental retardation. The spasms are described as sudden, brief contractions of one or more muscle groups, and may be followed by a longer (less than 10 seconds) tonic phase.

Most often the spasms occur in clusters during which the intensity or the frequency of the spasms may increase progressively to a peak, decline, or cease. The clusters tend to occur soon after arousal from sleep. They are not a feature of falling asleep.

The spasms usually involve the muscles of the neck, trunk, and extremities. The intensity of the contraction and the number of muscle groups involved varies in different attacks and from infant to infant. Neurological abnormalities other than seizures and retardation--such as cerebral atrophy, congenital abnormalities and hydrocephalus--are commonly reported among patients with IS.

Some patients may be treated successfully with either ACTH (adrenocorticotrophic hormone) or prednisone. The effectiveness of benzodiazepines or of antiepileptic drugs is doubtful.

IS is one of the most devastating seizure disorders affecting infants. Spontaneous cessation of spasms occurs in most patients with increasing age, and in some cases within the first month after onset. Overall, however, the prognosis for patients with IS is generally poor because a large number of these individuals have neurological impairment prior to the onset of spasms.

Information provided by the
National Institute of Neurological Disorders and Stroke
National Institutes of Health

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.