Precise characterization and quantification of infantile spasms

Authors

  • Dr. Peter Kellaway PhD,

    Corresponding author
    1. Departments of Neurology (Neurophysiology) and Pediatrics, Baylor College of Medicine, Houston, TX
    2. Neurophysiology Service and the Blue Bird Clinic, The Methodist Hospital, Houston, TX
    • Department of Neurology (Neurophysiology), Baylor College of Medicine, 1200 Moursund Ave, Houston, TX 77030
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  • Richard A. Hrachovy MD,

    1. Departments of Neurology (Neurophysiology) and Pediatrics, Baylor College of Medicine, Houston, TX
    2. Neurophysiology Service and the Blue Bird Clinic, The Methodist Hospital, Houston, TX
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  • James D. Frost Jr MD,

    1. Departments of Neurology (Neurophysiology) and Pediatrics, Baylor College of Medicine, Houston, TX
    2. Neurophysiology Service and the Blue Bird Clinic, The Methodist Hospital, Houston, TX
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  • Thomas Zion MD

    1. Departments of Neurology (Neurophysiology) and Pediatrics, Baylor College of Medicine, Houston, TX
    2. Neurophysiology Service and the Blue Bird Clinic, The Methodist Hospital, Houston, TX
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Abstract

With the use of a time-synchronized video and polygraphic recording system, 5,042 infantile spasms were monitored and analyzed in 24 infants aged 1 to 43 months. Of these, 33.9% were flexor, 22.5% extensor, and 42.0% mixed flexor-extensor. Sometimes the spasms were followed by a period of akinesia and diminished responsiveness lasting up to 90 seconds, and rarely (1.0%) this “arrest” effect constituted the entire seizure. More than one type of seizure occurred in 21 of the 24 infants. In the same number, 78.3% of the seizures occurred in clusters, and the intensity and frequency of the spasms in each cluster often increased to a peak, then progressively decreased until they stopped. Predominantly, the clusters occurred soon after arousal from sleep. The number of seizures occurring at night (55.2%) was similar to the diurnal number (44.8%). The electroencephalographic seizure pattern was variable, but a marked generalized attenuation of electrical activity was a feature of 71.7% of the attacks. Attenuation episodes of similar degree and duration occurred with no evidence of a seizure.

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