Lissencephaly-pachygyria spectrum
Updates to Article Attributes
The lissencephaly-pachygyria spectrum is useful in describing the spectrum of diseases that cause relative smoothness of the brain surface and includes:
- agyria: no gyri
- pachygyria: broad gyri
- lissencephaly: smooth brain surface
It is a basket term for a number of congenital cortical malformations characterised by absent or minimal sulcation.
Lissencephaly-pachygyria can be further divided into types I (classic) and type II, which differ in clinical presentation, underlying genetic abnormalities, and both microscopic and macroscopic (including imaging) appearances 2,6. They themselves represent a heterogeneous group of disorders. This article highlights a few generalities and outlines the differences between the two types, which are otherwise discussed separately:
Clinical presentation
Type I (classic) lissencephaly typically presents with marked hypotonia and paucity of movement.
Type II lissencephaly is associated with muscular dystrophy-like syndromes and includes Walker-Warburg syndrome, Fukuyama syndrome, and muscle-eye-brain (MEB) disease 2,6.
Radiographic features
Although lissencephaly can be identified on all cross-sectional modalities (antenatal and neonatal ultrasound, CT and MRI), MRI is the modality of choice to fully characterise the abnormalities.
MRI
Type I and type II lissencephaly demonstrate vaguely similar appearances (thus the common term lissencephaly) but different macroscopic and imaging appearances are visible.
Type I (classic) lissencephaly can appear as the classic hour glass or figure-8 appearance or with a few poorly formed gyri (pachygyria) and a smooth outer surface. It is usually associated with band heterotopia.
Type II lissencephaly on the other hand has a microlobulated surface referred to as a cobblestone complex. Band heterotopia is not evident and the cortex is thinner than in type I.
History and etymology
Lissencephaly is derived from the Greek word λισσος (lissos), meaning smooth 7.
See also
-</ul><h4>Clinical presentation</h4><p>Type I (classic) lissencephaly typically presents with marked hypotonia and paucity of movement.</p><p>Type II lissencephaly is associated with muscular dystrophy-like syndromes and includes <a href="/articles/walker-warburg-syndrome-1">Walker-Warburg syndrome</a>, <a href="/articles/fukuyama-syndrome">Fukuyama syndrome</a>, and <a href="/articles/muscle-eye-brain-meb-disease">muscle-eye-brain (MEB) disease</a> <sup>2,6</sup>.</p><h4>Radiographic features</h4><p>Although lissencephaly can be identified on all cross-sectional modalities (antenatal and neonatal ultrasound, CT and MRI), MRI is the modality of choice to fully characterise the abnormalities.</p><h5>MRI </h5><p>Type I and type II lissencephaly demonstrate vaguely similar appearances (thus the common term lissencephaly) but different macroscopic and imaging appearances are visible.</p><p>Type I (classic) lissencephaly can appear as the classic <a href="/articles/hour-glass-brain">hour glass</a> or <a href="/articles/figure-8-brain">figure-8</a> appearance or with a few poorly formed gyri (pachygyria) and a smooth outer surface. It is usually associated with <a href="/articles/band-heterotopia">band heterotopia</a>.</p><p>Type II lissencephaly on the other hand has a microlobulated surface referred to as a cobblestone complex. Band heterotopia is not evident and the cortex is thinner than in type I.</p><h4>See also</h4><ul>- +</ul><h4>Clinical presentation</h4><p>Type I (classic) lissencephaly typically presents with marked hypotonia and paucity of movement.</p><p>Type II lissencephaly is associated with muscular dystrophy-like syndromes and includes <a href="/articles/walker-warburg-syndrome-1">Walker-Warburg syndrome</a>, <a href="/articles/fukuyama-syndrome">Fukuyama syndrome</a>, and <a href="/articles/muscle-eye-brain-meb-disease">muscle-eye-brain (MEB) disease</a> <sup>2,6</sup>.</p><h4>Radiographic features</h4><p>Although lissencephaly can be identified on all cross-sectional modalities (antenatal and neonatal ultrasound, CT and MRI), MRI is the modality of choice to fully characterise the abnormalities.</p><h5>MRI </h5><p>Type I and type II lissencephaly demonstrate vaguely similar appearances (thus the common term lissencephaly) but different macroscopic and imaging appearances are visible.</p><p>Type I (classic) lissencephaly can appear as the classic <a href="/articles/hour-glass-brain">hour glass</a> or <a href="/articles/figure-8-brain">figure-8</a> appearance or with a few poorly formed gyri (pachygyria) and a smooth outer surface. It is usually associated with <a href="/articles/band-heterotopia">band heterotopia</a>.</p><p>Type II lissencephaly on the other hand has a microlobulated surface referred to as a cobblestone complex. Band heterotopia is not evident and the cortex is thinner than in type I.</p><h4>History and etymology</h4><p>Lissencephaly is derived from the Greek word λισσος (lissos), meaning smooth <sup>7</sup>. </p><h4>See also</h4><ul>
References changed:
- 7. Ian Brookes. The Chambers Dictionary. (2018) <a href="https://books.google.co.uk/books?vid=ISBN9780550101853">ISBN: 9780550101853</a><span class="ref_v4"></span>
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