Clinicians will subjectively determine the malformation based on the degree of malposition and the extent of thickened abnormal grey differentiation present.
[2] Pachygyria is caused by a breakdown in the fetal neuronal migration process due to genetic or possibly environmental influences.
One of the best known and most common types of neuronal migration disorders is lissencephaly, a diffuse cortical malformation relating directly to agyria and pachygyria.
[4] The abnormal migration of the neurons causes them to not reach their proper final destinations, which results in failure of the sulci and gyri to form.
[3] Below, the mutations of LIS1 or DCX genes are discussed as they are most commonly linked to neuronal migration disorders including lissencephaly-pachygyria and subcortical band heterotopia.
The protein is highly conserved and studies have shown that it participates in cytoplasmic dynein-mediated nucleokinesis, somal translocation, cell motility, mitosis, and chromosome segregation.
Studies have shown that addition of PAF or inhibition of platelet-activating factor acetylhydrolase (PAF-AH) decreases cerebellar granule cell migration in vitro.
Patients with missense mutations tend to have less severe symptoms, pachygyria, and rare cases of subcortical band heterotopia.
Generally, injury to muscle-nerves controlled by the brain's left side will cause a right body deficit, and vice versa.
Some children with quadriplegia also have hemiparetic tremors, an uncontrollable shaking that affects the limbs on one side of the body and impairs normal movement.
[citation needed] Pachygyria, lissencephaly (smooth brain), and polymicrogyria (multiple small gyri) are all the results of abnormal cell migration.
The abnormal migration is typically associated with a disorganized cellular architecture, failure to form six layers of cortical neurons (a four-layer cortex is common), and functional problems.
[citation needed] Normally, the brain cells begin to develop in the periventricular region (germinal matrix) and then migrate from medial to lateral, to form the cerebral cortex.
[7] Diffuse pachygyria (a mild form of lissencephaly) can be seen on an MRI as thickened cerebral cortices with few and large gyri and incomplete development of the Sylvian fissures.
Grade 2 is observed in children with Miller–Dieker syndrome (a combination of lissencephaly with dysmorphic facial features, visceral abnormalities, and polydactyly).
Polymicrogyria is characterized by many small gyri separated by shallow sulci, slightly thin cortex, neuronal heterotopia and enlarged ventricle and is often superimposed on pachygyria.
Another common treatment is a gastrostomy (insertion of a feeding tube) to reduce possible poor nutrition and repeated aspiration pneumonia.
[4] Microcephalic osteodysplastic primordial dwarfism (MOPD) type II is an autosomal multisystem disorder including severe pre- and post-natal growth retardation, microcephaly with Seckel syndrome–like facial appearance, and distinctive skeletal alterations.