A Case of Abnormal Movements in an Infant
Austin Quinn, MD, and Meghan Beucher, MD
CASE:
The patient is a 4 month-old ex-full term fully vaccinated otherwise healthy male who presented to the ED with one week of abnormal movements. The patient's mother stated that over the past week he had had increasingly frequent clusters of 5 or 6 episodes of flexing his hips and arms in toward his trunk, accompanied by abnormal eye movements with upward deviation and head drop. She sent videos to the PCP who felt it was from gas pain and started the patient on simethicone, without improvement in symptoms. Mother commented that they appeared to happen more often before sleep, but could happen when the patient was wide awake. He appeared to remain conscious throughout the episodes and would often cry afterwards.
He had previously been meeting developmental milestones. There was no family history of seizure or other related conditions. He had otherwise been in his normal state of health without fever, rash, nausea, vomiting, diarrhea, sick contacts, etc. He had no history of travel, exposure to exotic animals, ticks, lead paint, or anything else out of the ordinary.
DIFFERENTIAL DIAGNOSIS:
The differential for abnormal movements in an infant is quite broad.
It includes non-epileptic causes such as:
Hiccups
Colic/discomfort
Tremor/jitteriness (from a number of potential causes - hypoglycemia, withdrawal etc.)
Sleep myoclonus
Benign myoclonus of infancy
Tonic reflex seizures of early infancy
Sandifer syndrome/reflux
Hyperekplexia (a pronounced startle reflex)
Electrolyte abnormalities
As well as epileptic etiologies:
Infantile spasm
Seizures
PHYSICAL EXAMINATION AND ED COURSE:
Vitals and examination of the patient were unrevealing. The patient's mother was able to show the child's movements in a video, similar to this example video. He had a few episodes in the emergency room that were seen by his providers, and looked similar to the video provided by mother.
Neurology was consulted and an EEG was obtained. Not long into the study, and after the neurology team was able to witness a few more episodes, the diagnosis of infantile spasm was made.
DISCUSSION:
Infantile Spasm:
Features:
This disease is made up of a triad of findings:
Spasms
Arrest of psychomotor development
Hypsarrhythmia (an EEG finding)
The spasms are normally a brief, sudden contraction of the neck, trunk, and extremities, lasting for a second or two. This phase is followed by a contraction phase lasting for about 10 seconds, before relaxation back to baseline[1]. It is common for patients to cry or be upset after a spell. These contractions typically occur in clusters, most frequently during the day.
Etiology:
This disorder affects 2-4/10,000 births. It equally affects males and females, and all races/ethnicities. Most cases occur sporadically and are not genetically inherited.
Symptoms typically present within 1 year of birth.
The most up to date thought is that infantile spasm is the clinical manifestation of nonspecific insults that occur at critical developmental moments in early brain development. Therefore, a number of brain malformations seen on imaging, chromosomal abnormalities, genetic conditions, congenital infections, metabolic derangements, and other conditions are thought to contribute. Many cases are ultimately idiopathic.
Prognosis:
Spasms typically start out isolated and infrequent. They tend to become more common, prompting parents to seek care. Children will then often start to experience abrupt developmental arrest and regression. Spasms will typically peak in frequency, with potentially hundreds of spasms per day, before then becoming less common over years until they typically disappear altogether by age 3 or 4[2].
The prognosis is poor and up to 33% of those affected will die from it. Of those who do not die, 50-90% will develop other forms of seizures. Almost all will have moderate to severe neurodevelopmental disability[3].
Management:
Diagnosis is made by EEG, which should be obtained in the emergency room or as an inpatient. Neurology should be consulted. It is often hospital- and consultant-dependent whether patients get full workups as an inpatient or an outpatient. Of course, if the patient is unstable or has concurrent medical problems requiring active inpatient management, they should be admitted.
Longer term, patients will require neuroimaging, most often in the form of MRI, as up to 20% of patients will have structural lesions that are thought to cause infantile spasm. If negative, sometimes PET scan is used[4]. A number of metabolic and other laboratory tests may also be used to determine the etiology, but this workup (including imaging) does not need to be done in the emergency room.
The treatment of choice is corticotropin, also known as ACTH. This should be initiated as soon as possible after the diagnosis is made. Patients with newly diagnosed infantile spasm require admission for this medication, further work up, and coordination of care.
The most important learning point from this case is to keep infantile spasm in mind while seeing an infant with reports of abnormal movements. This is an important and time-sensitive diagnosis to make, and is easy to overlook in a well appearing child with a normal examination.
Author: Austin Quinn, MD, PGY3
Faculty Reviewer: Meghan Beucher, MD
References:
Pellock JM, Hrachovy R, Shinnar S, et al. Infantile spasms: a U.S. consensus report. Epilepsia 2010; 51:2175.
Wong M, Trevathan E. Infantile spasms. Pediatr Neurol 2001; 24:89.
Koo B, Hwang PA, Logan WJ. Infantile spasms: outcome and prognostic factors of cryptogenic and symptomatic groups. Neurology 1993; 43:2322.
Chugani HT, Conti JR. Etiologic classification of infantile spasms in 140 cases: role of positron emission tomography. J Child Neurol 1996; 11:44.