Lissencephaly-pachygyria spectrum
Updates to Article Attributes
The lissencephaly-pachygyria spectrum is a useful way to describe the spectrum of diseases that cause relative smoothness of the brain surface and includes 1:
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.
Types
Lissencephaly-pachygyria can be further divided into types I (classic) and type II (cobblestone). They differ in clinical presentation, underlying genetic abnormalities, as well as 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 1:
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 hourglass 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
classification system for malformations of cortical development
lissencephaly type I - subcortical band heterotopia spectrum
DifferntialDifferential diagnosis
Microcephaly with a simplified gyral pattern which describedescribes a reduced number of gyri and shallow sulci with a normal cortical thickness and architecture.
-</ul><h4>Differntial diagnosis</h4><p><a href="/articles/microcephaly-with-a-simplified-gyral-pattern" title="Microcephaly with a simplified gyral pattern">Microcephaly with a simplified gyral pattern</a> which describe a reduced number of gyri and shallow sulci with a normal cortical thickness and architecture</p>- +</ul><h4>Differential diagnosis</h4><p><a href="/articles/microcephaly-with-a-simplified-gyral-pattern" title="Microcephaly with a simplified gyral pattern">Microcephaly with a simplified gyral pattern</a> which describes a reduced number of gyri and shallow sulci with a normal cortical thickness and architecture.</p>
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