Radiology Teaching Files > Case 273885

Contributed by: Faculty and residents Children's Hospital, Radiologist, Children's Health System, Birmingham, Alabama., USA.
Patient: 7 month old male
History: developmental delay

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Fig. 9: Normal gyral/sulcal pattern of a 2 month old child

Fig. 10: Normal gyral/sulcal pattern of a two month old child

US- Smooth brain with lack of normal sulcal/gyral pattern. No intraventricular hemorrhage is evident.

MRI- Smooth brain, ventriculomegaly, white matter hypoplasia, poor gray-white differentiation, wide sylvian fissures, and wide central sulci. Thick and flat cortex.

Diagnosis: Agyria/Pachygyria Complex

Agyria-pachygyria is a disease of neuronal migration characterized by total or partial absence of sulci and thickened cortical mantle[1-4]. Pachygyria was considered as a less severe form of agyria-pachygyria complex and had a broader spectrum of clinical features than agyria. In many cases, agyria and pachygyria coexist in the same patient[1]. Although some of these disorders have a genetic basis, the cause of the migrational arrest is still unknown. Seizure and development delay are the most common presentations. These patients are always retarded in motor or intellectual function.

The advent of CT and MRI have made the diagnosis of agyria-pachygyria during life possible. In addition to neuroimaging studies, EEG abnormalities are also helpful in the diagnosis of agyria-pachygyria[5-7]. These abnormalities in agyria-pachygyria described previously including generalized high amplitude fast activity, high amplitude sharp- and slow-wave complexes and an alternating pattern consisting of bursts of sharp waves alternating with periods of electrocerebral depression.

Agyria is often associated with dysgenetic syndromes such as Miller-Dieker (A developmental defect of the brain caused by incomplete neuronal migration and characterized by smoothness of the surface of the brain (lissencephaly) occurring in association with absence of the sulci and gyri (agyria) and thickening of the cerebral cortex with four rather than six layers (pachygyria), microcephaly, characteristic facial appearance, retarded growth and mental development, neurological complications, and multiple abnormalities of the brain, kidneys, heart, gastrointestinal tract, and other organs.) and Walker-Warburg (cobblestone lissencephaly II).



1. Kuzniecky R.I. Magnetic resonance imaging in developmental disorders of the cerebral cortex. Epilepsia. 1994;35 (suppl. 6) S44-56.

2. Andel JFR, Arts WFM, Weerd AW. EEG and evoked potentials in a series of 21 patients with lissencephaly type 1. Neuropediatrics 1992; 23, 4-9.

3. Andel JFR, Arts WFM, Barth PG, Loonen MCB. Diagnostic features and clinical signs in 21 patients with lissencephaly type 1. Dev. Med. Child Neurol. 1990;32,707-17.

4. Aicardi J. The agyria-pachygyria complex: a spectrum of cortical malformations. Brain Dev 1991;13:1-8.

5. Hakada S.,Watanabe K., Hara K., Miyazaki S. The evolution of electroencephalographic features in lissencephalic syndrome. Brain Dev 1979;1:277-83

6. Gastaut H., Pinsard N, Raybaud C., Aicardi J. Zifkin B. Lissencephaly (agyria-pachygyria): clinical findings and serial EEG studies. Dev. Med. Child Neuro. 1987;29:167-80.

7. Kriss A., Boyd S., Thompson D., Harris C.M. A study of EEG, electroretinogram, visual evoked potential, and eye movements in classical lissencephaly. Dev. Med. Child Neuro. 2000;42:48-52.

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Additional Details:

Case Number: 273885Last Updated: 01-05-2004
Anatomy: Cranium and Contents   Pathology: Congenital
Modality: MR, USExam Date: Access Level: Readable by all users
Keywords: joel mixon

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