Microcephaly with a simplified gyral pattern
Updates to Article Attributes
Microcephaly with a simplified gyral pattern (MSG(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; the brain never forms normallycould 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 microcephaliessome show an abnormally simplified gyral pattern without thickening of the cerebral cortex, this is known as(microcephalymicrocephaly with a simplified gyral pattern (MSG))
secondary microcephaly: normal continued brain development is arrested by some defined insult such as a hypoxic-ischaemic insult, TORCH infection, or metabolic disease
Epidemiology
Associations
reduced white matter volume
developmental brain anomalies: e.g.corpus callosal hypogenesis and hypoplasia, periventricular heterotopia
delayed myelination
Clinical presentation
patientsPatients with MSGmicrocephaly with a simplified gyral pattern 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, andor cortical organisation stage. Microcephaly is classified as a disorder of cell proliferation1.
Radiographic features
GradingThe 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
AThere is a strong correlation between the degree of microcephaly, the volume of white matter, and the presence of a simplified gyral pattern 1.
Differential diagnosis
Corticalcortical migrational disorders such as pachygyria and lissencephaly in which the cortex is thickenedSecondarysecondary microcephaly occurring secondary to a brain insultsuch as that associated with(including hypoxic ischaemicinsultinjury, TORCHinfections orinfection, 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 <a href="/articles/microcephaly" title="Microcephaly">microcephaly</a> 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><strong>primary (genetic) microcephaly:</strong> small but architecturally normal brain; the brain never forms normally</p>
- +<ul>
- +<li><p>could be familial (autosomal dominant or recessive) or syndromic (e.g. Edward or Down)</p></li>
- +<li><p>some show an abnormally simplified gyral pattern without thickening of the cerebral cortex, this is known as microcephaly with a simplified gyral pattern (MSG)</p></li>
- +</ul>
- +</li>
- +<li><p><strong>secondary microcephaly:</strong> normal continued brain development is arrested by some defined insult such as a hypoxic-ischaemic insult, TORCH infection, or metabolic disease</p></li>
- +</ul><h4>Epidemiology</h4><h5>Associations</h5><ul>
- +<li><p>reduced white matter volume</p></li>
- +<li><p>developmental brain anomalies: e.g. <a href="/articles/dysgenesis-of-the-corpus-callosum" title="Corpus callosum agenesis">corpus callosal hypogenesis and hypoplasia</a>, <a href="/articles/subependymal-grey-matter-heterotopia-1" title="Periventricular nodular heterotopia">periventricular heterotopia</a></p></li>
- +<li><p>delayed myelination</p></li>
- +</ul><h4>Clinical presentation</h4><p>Patients with microcephaly with a simplified gyral pattern may have variable degrees of mental retardation and neurodevelopmental delay.</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, or cortical organisation stage. Microcephaly is classified as a disorder of cell proliferation <sup>1</sup>.</p><h4>Radiographic features</h4><p>The 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>There is 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 a brain insult (including <a href="/articles/anoxic-brain-injury" title="Hypoxic-ischemic injury">hypoxic ischaemic</a> injury, <a href="/articles/congenital-infections-mnemonic" title="TORCH infection">TORCH </a>infection, metabolic diseases) in which the brain parenchymal architecture is abnormal</p></li>
Image 1 MRI (T1) ( update )
Image 3 CT (non-contrast) ( update )
Image 5 MRI (T2) ( update )
Image 7 CT (non-contrast) ( update )
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