Microcephaly with a simplified gyral pattern
Updates to Article Attributes
Microcephaly with a simplified gyral pattern (MSG) is a congenital malformation characterised by microcephaly, accompanied by a simplified gyral pattern. The term “simplified gyral pattern” is often used to describe a reduced number of gyri and shallow sulci with a normal cortical thickness and architecture.
Terminology
Congenital microcephaly is divided into two main types:
primary (genetic) microcephaly in which the patient usually has a small but architecturally normal brain. Primary microcephaly could be familial (autosomal dominant or recessive) or syndromic (e.g. Edward or Down).
secondary microcephaly which occurs secondary to brain insults such as that associated with hypoxic-ischaemic insult, TORCH infections, or metabolic disease.
Some primary microcephalies show an abnormally simplified gyral pattern without thickening of the cerebral cortex, this is known as (microcephaly with a simplified gyral pattern (MSG)).
Clinical presentation
patients with MSG may have variable degrees of mental retardation and neurodevelopmental delay
Associations
Reduced white matter volume
developmental brain anomalies, such as corpus callosal hypogenesis and hypoplasia, periventricular nodular heterotopia
delayed myelination
Pathology
Numerous genes have been found to be associated with simplified gyral pattern, however, the pathophysiology is still not completely understood
Malformations of cortical development are classified depending on the stage at which the developmental process was disturbed, either at cell proliferation/apoptosis stage, neuronal migration stage, and cortical organisation stage. Microcephaly is classified as a disorder of cell proliferation1
Radiographic features
Grading system for sulcation includes
mildly simplified gyral pattern: width of gyri < depth of sulci
moderately simplified: width of gyri = depth of sulci
severely simplified: width of gyri > depth of sulci
A strong correlation between the degree of microcephaly, the volume of white matter, and the presence of a simplified gyral pattern 1
Differential diagnosis
Cortical migrational disorders such as pachygyria and lissencephaly in which the cortex is thickened
Secondary microcephaly occurring secondary to brain insult such as that associated with hypoxic ischaemic insult, TORCH infections or metabolic diseases in which the brain parenchymal architecture is abnormal
See also
-<p><strong>Microcephaly with a simplified gyral pattern</strong> (<strong>MSG</strong>) is a congenital malformation characterised by microcephaly, accompanied by a simplified gyral pattern. The term “simplified gyral pattern” is often used to describe a reduced number of gyri and shallow sulci with a normal cortical thickness and architecture.</p><h4>Terminology</h4><p>Congenital <a href="/articles/microcephaly" title="Microcephaly">microcephaly</a> is divided into two main types:</p><ul>-<li><p>primary (genetic) microcephaly in which the patient usually has a small but architecturally normal brain. Primary microcephaly could be familial (autosomal dominant or recessive) or syndromic (e.g. Edward or Down).</p></li>-<li><p>secondary microcephaly which occurs secondary to brain insults such as that associated with hypoxic-ischaemic insult, TORCH infections, or metabolic disease.</p></li>-</ul><p>Some primary microcephalies show an abnormally simplified gyral pattern without thickening of the cerebral cortex, this is known as (microcephaly with a simplified gyral pattern (MSG)).</p><h4>Clinical presentation</h4><p>patients with MSG may have variable degrees of mental retardation and neurodevelopmental delay</p><h4>Associations</h4><p>Reduced white matter volume</p><p>developmental brain anomalies, such as corpus callosal hypogenesis and hypoplasia, periventricular nodular heterotopia</p><p>delayed myelination</p><h4>Pathology</h4><p>Numerous genes have been found to be associated with simplified gyral pattern, however, the pathophysiology is still not completely understood</p><p>Malformations of cortical development are classified depending on the stage at which the developmental process was disturbed, either at cell proliferation/apoptosis stage, neuronal migration stage, and cortical organisation stage. Microcephaly is classified as a disorder of cell proliferation<sup>1</sup></p><h4>Radiographic features</h4><p>Grading system for sulcation includes</p><ul>-<li><p>mildly simplified gyral pattern: width of gyri < depth of sulci</p></li>-<li><p>moderately simplified: width of gyri = depth of sulci</p></li>-<li><p>severely simplified: width of gyri > depth of sulci</p></li>-</ul><p>A strong correlation between the degree of microcephaly, the volume of white matter, and the presence of a simplified gyral pattern <sup>1</sup></p><h4>Differential diagnosis</h4><ul>-<li><p>Cortical migrational disorders such as pachygyria and <a href="/articles/lissencephaly-pachygyria-spectrum-2" title="Lissencephaly-pachygyria spectrum">lissencephaly</a> in which the cortex is thickened</p></li>-<li><p>Secondary microcephaly occurring secondary to brain insult such as that associated with <a href="/articles/anoxic-brain-injury" title="Hypoxic-ischemic injury">hypoxic ischaemic</a> insult, <a href="/articles/congenital-infections-mnemonic" title="TORCH infection">TORCH </a>infections or metabolic diseases in which the brain parenchymal architecture is abnormal</p></li>- +<p><strong>Microcephaly with a simplified gyral pattern</strong> (<strong>MSG</strong>) is a congenital malformation characterised by microcephaly, accompanied by a simplified gyral pattern. The term “simplified gyral pattern” is often used to describe a reduced number of gyri and shallow sulci with a normal cortical thickness and architecture.</p><h4>Terminology</h4><p>Congenital <a href="/articles/microcephaly" title="Microcephaly">microcephaly</a> is divided into two main types:</p><ul>
- +<li><p>primary (genetic) microcephaly in which the patient usually has a small but architecturally normal brain. Primary microcephaly could be familial (autosomal dominant or recessive) or syndromic (e.g. Edward or Down).</p></li>
- +<li><p>secondary microcephaly which occurs secondary to brain insults such as that associated with hypoxic-ischaemic insult, TORCH infections, or metabolic disease.</p></li>
- +</ul><p>Some primary microcephalies show an abnormally simplified gyral pattern without thickening of the cerebral cortex, this is known as (microcephaly with a simplified gyral pattern (MSG)).</p><h4>Clinical presentation</h4><p>patients with MSG may have variable degrees of mental retardation and neurodevelopmental delay</p><h4>Associations</h4><p>Reduced white matter volume</p><p>developmental brain anomalies, such as corpus callosal hypogenesis and hypoplasia, periventricular nodular heterotopia</p><p>delayed myelination</p><h4>Pathology</h4><p>Numerous genes have been found to be associated with simplified gyral pattern, however, the pathophysiology is still not completely understood</p><p>Malformations of cortical development are classified depending on the stage at which the developmental process was disturbed, either at cell proliferation/apoptosis stage, neuronal migration stage, and cortical organisation stage. Microcephaly is classified as a disorder of cell proliferation<sup>1</sup></p><h4>Radiographic features</h4><p>Grading system for sulcation includes</p><ul>
- +<li><p>mildly simplified gyral pattern: width of gyri < depth of sulci</p></li>
- +<li><p>moderately simplified: width of gyri = depth of sulci</p></li>
- +<li><p>severely simplified: width of gyri > depth of sulci</p></li>
- +</ul><p>A strong correlation between the degree of microcephaly, the volume of white matter, and the presence of a simplified gyral pattern <sup>1</sup></p><h4>Differential diagnosis</h4><ul>
- +<li><p>Cortical migrational disorders such as pachygyria and <a href="/articles/lissencephaly-pachygyria-spectrum-2" title="Lissencephaly-pachygyria spectrum">lissencephaly</a> in which the cortex is thickened</p></li>
- +<li><p>Secondary microcephaly occurring secondary to brain insult such as that associated with <a href="/articles/anoxic-brain-injury" title="Hypoxic-ischemic injury">hypoxic ischaemic</a> insult, <a href="/articles/congenital-infections-mnemonic" title="TORCH infection">TORCH </a>infections or metabolic diseases in which the brain parenchymal architecture is abnormal</p></li>
Image 9 MRI (T2) ( create )
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