What are infantile spasms?
Also known as "West Syndrome," "salaam attacks," "jacknife spasm," "generalized flexion epilepsy syndrome," among others, Infantile spasms are a rare catastrophic epileptic disorder typically found in infants between 4-8 months of age. Although more uncommon, an onset of spasms can occur much earlier in life during the neonatal period or in utero, or later in childhood after 1 year of age. Infantile spasms were first reported in 1841 by Dr. WJ West in a letter to the editor of The Lancet, where events were described as "bobbings" that "cause a complete heaving of the head forward towards his knees, and then immediately relaxing into the upright position." Dr. West was referring to his own son. Since this first report in 1841, medical professionals have made much progress in their recognition for evalaution and treatment of infantile spasms. However, infantile spasms have difficult to control tendencies, and little is known about the neuroanatomic and electrophysiologic mechanisms that present them. It is believed by some that there may be abnormal interactions between the cortex and brainstem structures. The term "infantile spasms" can be used to describe the specific seizure type in the syndrome, the epilepsy syndrome itself, or both.
What do infantile spasms look like?
Manifestation of infantile spasms generally begin with a quick, rapid, contraction of trunk and limb musculature that relaxes gradually within less than a second, or up to several seconds. Both "flexor" and "extenstion" spasms are common. Characterization includes initial contraction phases, followed by a tonic phase. "Hiccups," 'jacknife," "self-hugging" and "situps" have been used as terms to describe them. Additionally, there are variations such as extension of both upper and lower extremeties, and subtle, brief head drops. Infantile spasms can be very intense and rigid, or extremely quick, and can evolve as such over time. Infantile spasms usually come in clusters. A cluster is measured by the amount of spasms that occur over a period of time, and can range anywhere from just a few spasms, to well over 100. A cluster of spasms can last less than 1 minute, to over 15 minutes in duration. Clusters typically occur after waking from prolonged sleep or a nap, and is followed by much discomfort. In more rarer occurrences, clusters of spasms can happen in sleep, or after stimulation such as bathing, feeding, yawning or sneezing, and can be followed by smiling and/or laughing behavior. Infantile spasms can also be incredibly subtle, easily unnoticed, and misdiagnosed as a Moro reflex, startle reflex and colic reflux.
Press "Play" on a video below for an example of infantile spasms - Notice how subtle the spasms can be.
How do doctors diagnose infantile spasms in young children? It isn't always easy, but generally there are three important factors considered when making the initial diagnosis of infantile spasms: age, semiology and a very distinct electroencephalography (EEG) pattern called hypsarrhythmia.
- Because infantile spasms typically begin within the first year of life, it is a disorder of the developing nervous system. However, later onset after 1 year of age does happen in much rarer occassions.
- The semiology, or physical signs of infantile spasms, appear to be specific and consistent. Please refer to the category above with information about what infantile spasms look like. However, other seizure types have been known to arise either sequentially or concurrently with infantile spasms. Additionally, the plateau of a child's development and regress of developmental milestones can happen and may be considered during a diagnosis.
- An EEG with a distinct pattern called hypsarrhythmia is characteristic of infantile spasms. This is a very high voltage, slow wave, chaotic and disorganized abnormality on the EEG. There is a variation from each moment in the duration and location in all cortical areas. There is also modified hypsarrhythmia, which may be less chaotic showing increased synchronization, asymmetry and a consistent focus of abnormal discharge. It is important to note that although other abnormal EEG patterns may be present in infantile spasms, hypsarrhythmia is specific and not found in any other syndromes.
Although an initial diagnosis can often easily be made using the three common factors listed above, making a determination for an etiological diagnosis, the underlying cause, can sometimes be very difficult and have a large impact on prognosis and treatment options. There is two main categories that separate the diagnosis of infantile spasms: cryptogenic and symptomatic.
- Cryptogenic involves cases where no cause for infantile spasms is identified due to lack of obvious brain damage and etiology. An estimated 30% of infantile spasms cases are considered cryptogenic.
- Symptomatic infantile spasms do have an identifiable cause that are characterized by a known etiology, and make up approximately 70% of cases. Common tests to determine the cause for infantile spasms include patient history, a physical and neurological examination, Magnetic Resonance Imaging (MRI), Positron emission tomography (PET), various other imaging studies, metabolic testing, genetic testing.
There is three main categories that separate the etiological determination for infantile spasms, if it is found: Prenatal Disorders, Perinatal Disorders and Postnatal Disorders. Conditions among these three categories are listed below. It is important to note that many specific underlying causes are then categorized in a much broader spectrum called Malformations of Cortical Development (MCD). MCD are increasingly recognized as an important cause of epilepsy and developmental delay. Please visit the Hemimegalencaphaly and Cortical Dysplasia specialty page to learn more. However, this is not a complete listing, as there are many underlying conditions that can result in an onset of infantile spasms.
Various treatment and therapy options exist for infantile spasms, and this is usually dependent upon the etiological diagnosis and determining what benefits will come out of a specific therapy trial. However, there are certain "frontline" antiepileptic drugs (AED) that are often considered first once a diagnosis is made. These AEDs posses a desirable efficacy, but do not always have the same result in every child. Please note that what is considered "frontline" may not be what is prescribed first. These may include (in no particular order): Adrenocorticotropic hormone (ACTH), Vigabatrin, Ketogenic diet, Prednisolone. Additional medications may also be considered, listed below. It is not uncommon for more than one medication to be prescribed at once. This is not a complete listing of all medications used to treat infantile spasms:
Resection surgery is a treatment consideration as well, generally following the failure of AED medical management. The appearance of localized abnormalities such as cortical dysplasia, porencephaly and tuberous sclerosis are among considering factors for surgery. Careful consideration is usually given during a surgical evaluation, and making a risk benefit assessment by the surgical team is important. Visit the Hemispherectomy Foundation's Medical Advisory Board for a listing of specialists with experience in infantile spasms and surgery. It is recommended by many specialists to receive proper surgical evaluation immediately following the failure of some of the frontline treatments to greatly increase the possibility of seizure resolution as soon as possible.
Hemispherectomy surgery is considered in a number of infantile spasms cases depending upon the underlying cause and proper evaluation by a specialty team. Some specific conditions that have resulted in hemispherectomy include:
Important Considerations Concerning Infantile Spasms
Infantile spasms in young children are particulary devastating to proper development. Having a good team of Early Intervention specialists to monitor developmental progress is an important part of the process, and arrangements should be made with a team immediately. Also, time is a critical factor involved, and if spasms are suspected, immediate attention from a specialist with pediatric neurology experience in infantile spasms should be sought. Stopping the seizures as soon as possible is what is most important. Visit the Resource page for more information about what available resources are in your area that may serve as a helpful starting point after receiving diagnosis.
Infantile Spasms Facts (Estimations will vary depending on source)
- Incidents are estimated to range from 1.5-2.0 per 10,000 live births, and occurring in more boys than girls.
- 90% of cases occur during the first year of life.
- It is estimated that one-fifth of children with infantile spasms develop Lennox-Gastaut syndrome (LGS), a severe epilepsy syndrome.
- One-third of children with infantile spasms develop autism.
- There is an estimated 6% - 33% mortality rate by the age of three.
- Cryptogenic infantile spasms patients have potentially a 30% - 50% cognitive impairment, compared with 80% - 95% in symptomatic etiology.
- Infantile spasms make up an estimated 2% of childhood epilepsies.
*Information used for this page was taken from various resources listed below, as well as personal experiences.
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Infantile Spasms Internet Links * To view a comprehensive list of cited publications
- Shields, WD, MD. May, 2006. Infantile Spasms: Little Seizures, BIG Consequences. American Epilepsy Society
- Glauser, Tracy A, MD. Kao, Amy, MD. April 26, 2010. Infantile Spasms (West Syndrome)
- Neuroscience News, September 4th, 2010. Guidelines Established For Treatment And Diagnosis Of Infantile Spasms.
- Gandey, Allison. June 19, 2010. Pediatric Epilepsy Patients Having Improved Outcomes After Surgery. (Login required)
- Infantile Spasms Information Page. National Institute of Neurological Disorders and Stroke.
- R. Duncan. 2001. Infantile Spasms: the original description of Dr West. John Libbey Eurotext.