Megalencephaly in infants and children. The possible role of increased dural sinus pressure

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Microvascular Decompression: Salient Surgical Principles and Technical Nuances

Published on: July 5, 2011

H D Portnoy, P D Croissant

    Archives of Neurology
    |May 1, 1978
    PubMed

    Insights

    Seven male infants with macrocephaly were found to have megalencephaly caused by increased sagittal sinus venous pressure. This condition, similar to benign intracranial hypertension, may be influenced by open cranial sutures in infants.

    Area of Science:

    • Pediatric Neurology
    • Neuroimaging
    • Cerebrospinal Fluid Dynamics

    Background:

    • Macrocephaly and suspected hydrocephalus in infants can present diagnostic challenges.
    • Understanding intracranial hydrodynamics is crucial for diagnosing pediatric neurological conditions.
    • Megalencephaly, characterized by an enlarged brain, requires investigation into its underlying causes.

    Purpose of the Study:

    • To investigate the cause of macrocephaly in seven male infants.
    • To explore the relationship between sagittal sinus venous pressure and megalencephaly.
    • To review intracranial hydrodynamics in conditions like benign intracranial hypertension and hydrocephalus.

    Main Methods:

    • Clinical evaluation of seven male infants presenting with macrocephaly.
    • Infusion studies to measure cerebrospinal fluid (CSF) formation and absorption rates.
    • Neuroimaging techniques including pneumoencephalography, ventriculography, and computerized tomography (CT).
    • Isotope cisternography to assess CSF pathways.

    Main Results:

    • All seven infants exhibited head enlargement exceeding two standard deviations.
    • Neuroimaging showed normal or minimally enlarged ventricles without progression.
    • CSF studies revealed normal absorption rates but high calculated sagittal sinus pressures.
    • Abnormal isotope cisternography findings were noted.

    Conclusions:

    • The studied macrocephaly was attributed to megalencephaly secondary to increased sagittal sinus venous pressure.
    • This condition shares similarities with benign intracranial hypertension (BIH).
    • Open cranial sutures in infants may contribute to transient nonhydrostatic brain parenchyma loading, causing mild, nonprogressive macrocephaly.

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