Infantile Spasms

Usually, infantile spasms occur in infants with serious brain disorders and developmental abnormalities that often have already been recognized. These disorders may include

Tuberous sclerosis complex Tuberous Sclerosis Complex (TSC) Tuberous sclerosis complex is a dominantly inherited genetic disorder in which tumors (usually hamartomas) develop in multiple organs. Diagnosis requires specific clinical criteria and imaging... read more is a common cause; prognosis is sometimes better when seizures are caused by this disorder than when seizures have other identifiable causes.

Sometimes the cause of infantile spasms cannot be identified.

Spasms begin with a sudden, rapid, tonic contraction of the trunk and limbs, sometimes for several seconds. Spasms range from subtle head nodding to contraction of the whole body. They involve flexion, extension, or, more often, both (mixed). The spasms usually occur in clusters, often several dozen, in close succession and occur typically after children wake up and occasionally when falling asleep. Sometimes, at first, they are mistaken for startles.

Developmental delays (see Childhood Development Childhood Development Descriptions of development are often divided into specific domains, such as gross motor, fine motor, language, cognition, and social/emotional growth. These designations are useful, but substantial... read more ) may be present before the onset of infantile spasm. In infants with normal development, developmental regression can occur (eg, children may stop smiling or lose the ability to sit up or roll over).

Rate of premature death ranges from 5 to 31% (1 Symptoms and signs reference Infantile spasms are seizures characterized by sudden flexion of the arms, forward flexion of the trunk, extension of the legs, and hypsarrhythmia on electroencephalography. Treatment is adrenocorticotropic... read more ) and is related to the etiology of the infantile spasms.

Previous history (eg, neonatal hypoxic-ischemic encephalopathy) and/or symptoms and signs suggest the diagnosis of infantile spasms in some children. Physical and neurologic examinations are done, but often no pathognomonic findings are identified except in tuberous sclerosis complex Tuberous Sclerosis Complex (TSC) Tuberous sclerosis complex is a dominantly inherited genetic disorder in which tumors (usually hamartomas) develop in multiple organs. Diagnosis requires specific clinical criteria and imaging... read more .

EEG is done to confirm the diagnosis and check for specific abnormalities. Typically, the interictal pattern is hypsarrhythmia (chaotic, high-voltage polymorphic delta and theta waves with superimposed multifocal spike discharges). Multiple variations (eg, focal or asymmetric hypsarrhythmia) are possible. The ictal pattern is usually a sudden, marked and diffuse attenuation of electrical activity.

Neuroimaging, preferably MRI, is done if it has not already recently been done.

Infantile spasms are not responsive to typical antiseizure medications.

The standard therapies for infantile spasms can be any one of the following.

ACTH can be given daily IM as either high-dose (150 units/m²) ACTH or low-dose (20 units/m²) ACTH. The Pediatric Epilepsy Research Consortium (PERC) recommends the higher dose, given for 2 weeks and then tapered down every 3 days until 29 days of treatment are completed. If low-dose therapy is tried and has not stopped spasms within 2 weeks, the higher dose is used.

Corticosteroids (eg, oral prednisone) are given for 4 to 7 weeks. A regimen recommended by PERC uses oral prednisolone as follows:

Vigabatrin is the drug of choice when the spasms are caused by tuberous sclerosis complex Tuberous Sclerosis Complex (TSC) Tuberous sclerosis complex is a dominantly inherited genetic disorder in which tumors (usually hamartomas) develop in multiple organs. Diagnosis requires specific clinical criteria and imaging... read more . It is also often used in children with an established preexisting serious brain injury or malformation and in those who do not tolerate or respond to ACTH. Dosage of oral vigabatrin is 25 mg/kg 2 times a day, increased gradually over about a week up to 75 mg/kg 2 times a day if needed. There is insufficient evidence that any other antiseizure medication or the ketogenic diet is effective.

In some patients with resistant spasms or with focal cortical malformation, epilepsy surgery Surgery A seizure is an abnormal, unregulated electrical discharge that occurs within the brain’s cortical gray matter and transiently interrupts normal brain function. A seizure typically causes altered... read more can eliminate seizures.

There is evidence that the more quickly effective therapy is initiated, the better the neurodevelopmental outcome, particularly when no cause is identified.