Malformations of cortical development. Clinical and imaging findings.

Transcription

1 Malformations of cortical development. Clinical and imaging findings. Poster No.: C-2086 Congress: ECR 2012 Type: Educational Exhibit Authors: I. Alba de Caceres, B. García-Castaño, L. Ibañez, E. Roa, A Paniagua, M. Andreu ; San Sebastian de los Reyes, Madrid/ES, Madrid/ES, San Sebastián de los Reyes/ES, madrid/es Keywords: Computer Applications-Detection, diagnosis, MR, CT, Neuroradiology brain, Congenital DOI: /ecr2012/C-2086 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 27

2 Learning objectives Know the different types malformations of cortical development and radiological manifestations. Show the clinical symptoms which led to the request for the imaging, as well as the variety and type of malformations most frequently found in our series of patients Background Malformations of cortical development cover a wide spectrum of disorders that depend on the time of neuronal inhibition takes place, which may be during the stages of neuronal proliferation, migration and organization. The etiologic agents are varied, and clinical manifestations as well. Most of the time are associated with epilepsy, but other forms of presentation have been described. Knowing the imaging findings is crucial, because subtle changes may go unnoticed. Imaging findings OR Procedure details NEURONAL DEVELOPMENT AND CAUSES THAT INHIBIT IT The germinal matrix forms in the subependymal layer of the walls of the lateral ventricles, in the seventh week of gestation, producing neurons and glial cells.this is the first step of cortical development named proliferative stage. Roughly the twelfth week of gestation, begins the neuronal migration stage, from the germinal matrix to the cortex and during this time, glial cells form bundles to determine the migration pathway. There are neurons that migrate parallel to the wall of the ventricle, forming the gray nuclei of the base of the brain. Page 2 of 27

3 The process of neuronal organization is located in the cortex, where neurons are distributed in cells layers form synapses with local and distal neurons.this stage starts at 22 weeks of fetal gestation. During development of the brain, interruption of neuroblast proliferation- differentiation, neuroblast migration or cortical organization may end up in malformations of cortical development. The causes that disrupt this process are varied, ranging from chromosomal malformations, congenital infections during pregnancy, prenatal ischemic injury, exogenous toxins and metabolic disorders. CLASSIFICATION OF DEVELOPMENTAL MALFORMATIONS Fig. 1: CLASSIFICATION SCHEME Page 3 of 27

4 The classification of developmental malformations are based on the first classification of Barkovich et al in The division is made according to time of embryological development in which neuronal alteration and secondary phenotypic expression occurs. However, it is an evolutionary process, continuous and dynamic. No separate or independent in the three stages in which it is classified. " Proliferation continues after migration begins, and migration continues as organization commences" (Barkovich et al, Neurology, : ). It is in this latest revision which is a modification based on the genetic causes rather than on phenotypic alterations, which mainly affects the anomalies of neuronal migration. Fig. 3: ABNORMAL PROLIFERATION I Microcephaly - This is a decrease head circumference, in the moment of birth, intrauterine undamaged. Page 4 of 27

5 Microlissencephaly - Microcephaly with smooth cortical surface and thickened cortex ( more tan 3 mm). It is the severe form, and usually coexists with other anomalies. Fig. 2: ABNORMAL NEURONAL PROLIFERATION II Tuberous sclerosis complex ( Bourneville-Pringle syndrome) - It is an inherited tumor disorder with multiorgan hamartomas. CNS hamartomas, all contain giant ballon cells. Cortical anomalies are the cortical/subcortical tubers, wich are WM lesions with thickened cortex and enlarged gyri. More tuber means more neurological syntoms. Also, there are white matter lesions along lines of neuronal migration. Almost 100% has SEN s ( calcified subependymal nodules) Page 5 of 27

6 Fig. 4: Tuberous complex case 1 Page 6 of 27

7 Fig. 5: Tuberous complex, case 2 Page 7 of 27

8 Fig. 6: Tuberous complex case 3 Focal cortical dysplasia of Taylor (FCDT)- Consists of cytoarchitectural disarray of the cortex caused by bizarre and disoriented neurons with of balloon cells in the subcortical white matter and cortex ( disorder has a histologic similar to tuberous sclerosis). MR i findings are usually cortical thickening, indistinctness of the cortical-medullary junction, and macrogyria.in the FCD with balloon cells, focal hyperintensity within the subcortical white matter can be seen on FSET2 and FLAIR MR i. It is important to make this distinction with neoplastic process, but findings as associated gray matter thickening or frontal location,support the diagnosis of FCD. Page 8 of 27

9 Fig. 7: Focal cortical dysplasia case1 Page 9 of 27

10 Fig. 8: Focal cortical dysplasia case2 Page 10 of 27

11 Fig. 9: Focal cortical dysplasia case 3 Hemimegalencephaly - It is a moderate or great enlargement, of part or entire whole cerebral hemisphere, which can be associated or not to increase the size of the cerebellum and brainstem ipsilateral. Cerebral cortex may be normal or dysplastic ( polymicrogyria, lissencephaly or heterotopia). Moreover, it can be isolated or be an alteration in the context of a syndrome (such as NF I). Ganglioglioma - Is an uncommon primary lesion of the CNS, are tumors of glial and neuronal elements that tend to grow slowly and produce focal symptoms, usually from expansion of the mass. If glial elements predominate the lesion is called ganglioglioma, but if neuronal elements predominate is called gangliocytoma. Page 11 of 27

12 They are most commonly seen in children and young adults and there is no gender preponderance. The common location is the temporal lobe, and other locations are the frontal, parietal, and occipital lobes. Fig. 10: Ganglioglioma Page 12 of 27

13 Fig. 11: ABNORMAL NEURONAL MIGRATION Neuronal migration goes from germinal matrices along radial glial fibers and axons to the cerebral cortex to begin the cortical organization. Lissencephaly has a lot subtypes based on the underlying genetic abnormality. MR findings are: thick cortex, subcortical WM thin, not gray-white matter interdigitation. Also, and as predominant finding there are smooth brain surface with agyria, but in the incomplete forms may be found some gyral along temporal and frontal lobe and pachygyria. Cobblestone Complex (Congenital Muscular Dystrophy) Page 13 of 27

14 MR i features in Cobblestone lissencephaly are, mainly ; irregular nodular brain surface with hypomielinitation of white matter, in children with ocular anomalies, and congenital muscular disorders. It results from overmigration external glial limitations, into the subarachnoid space. There are three syndromes: Walker-Warburg syndrome (WWS) (most severe),fukuyama congenital muscular dystrophy (FCMD) (mildest); and muscle-eye-brain (MEB) (intermediate). Heterotopias They are groups of normal neurons in atipic locations, located from the subependymal area to the cerebral cortex, where cells stop their way in the migration. Heterotopias are clasiffied depending on where it is located and where therefore the stop occurs in the pathway of migration. Periventricular or subependymal heterotopias (PVH) are located in close proximity to the ventricular wall. They are commonly seen in the region of the trigone and occipital horns of the lateral ventricles as round nodules isointenses togray matter. Page 14 of 27

15 Fig. 12: Periventricular subependymal heterotopias Page 15 of 27

16 Fig. 13: Subependymal heterotopias Subcortical Heterotopias (SCH) are located in the subcortical area or in deep white matter. The affected hemisphere may decrease in size as a result of the decreased volumen of the neurons. Page 16 of 27

17 Fig. 14: Subcortical heterotopia and decrease size hemisphere Page 17 of 27

18 Fig. 15: Subcortical heterotopia and hypoplasia corpus callosum I Page 18 of 27

19 Fig. 16: Subcortical heterotopia and hypoplasia corpus callosum II Page 19 of 27

20 Fig. 17: ABNORMAL NEURONAL ORGANIZATION Polymicrogyria- The imaging findings are ; many small prominent convolutions separated by shallow sulci with an irregular appearance of the cortical surface and cortical white matter. It may be uni or bilateral,more small or more large,and symmetric or asymmetric. Syndromes affect the cognitive regions and use to be bilateral. It presents with epilepsy and cognitive delay. Page 20 of 27

21 Fig. 18: BILATERAL POLYMICROGYRIA Schizcencephaly Anomaly that happens during cortical organization, we can see a cleft lined with gray matter in hemispheres, connecting subarachnoid space with ventricular system ( lateral ventricle). Cleft may be uni or bilateral. This anomaly may be of the open-lip or closed-lip type. And, might be associated with septo-optic displasia, absence of septum pellucidum, pachygyria, polymicrogyria and heterotopias. Page 21 of 27

22 Fig. 19: CLOSED LIP SCHIZENCEPHALY Page 22 of 27

23 Fig. 20: BILATERAL SCHIZENCEPHALY Page 23 of 27

24 Fig. 21: CLOSED LIP SCHYZENCEPHALY II Cortical dysplasia without ballon cells -It is a cortical dysplasia without abnormal cells. MR diagnosis is difficult and also there is a blurring at the junction of the gray-white with thickened gyrus. NEUROLOGICAL FINDINGS There are a variety of neurologic problems referred malformation cortical development. Thanks to MR image, these anomalys are increasing frequency diagnosed, and may be associated with differents symtoms and clinical features. Seizures are the clinical cause more often associated with developmental malformations. In our series appears in 61% of cases, of which 72% were generalized tonic-clonic seizures, and 18% were complex partial seizures. Page 24 of 27

25 Psychomotor delay appears in 16 %, one case associated epileptic seizures. Attention-deficit/hiperactivity disorder has been found in 11%, as primary symptom. Migraine headaches appears in 11% as well. Only one case had hemiparesis with no more clinical alterations. In one case with seizure, cortical visual impairment was found. There are many other symptoms founded in cortical disorders as for example ; generalized hypotonia, nystagmus, ataxia However, the two most common symptoms are seizures isolated or associated with psychomotor retardation Conclusion Become familiar with the diverse findings that are seen in cortical development malfomations,because there are very subtle findings that may be overlooked or confused with other injuries. Also, knowing the correct classification based on the different stages of development is important for assessing associated anomalies, because the classification is based on the earliest abnormal step. In our serie, the 20 patients ranged in age from 4 years to 50 years, with a mean age of 25 years and a median age of 25 years, as well. There were 12 female and 8 male patients. Focal cortical dysplasia, has been most frequently founded in our serie, about 28%, followed by esquizencephaly, also at 28 % considering that a case was associated with heterotopias. Heterotopias in 22%. Cortical tubers (tuberous sclerosis complex) in 16%. PMG and Ganglioglioma in 5 %. Knowing the symptoms is crucial, and although the epilepsy is often the initial reason for which imaging are performed, there are other clinical symtoms associated with them; as has been previously referred. Personal Information Page 25 of 27

26 IGNACIO ALBA DE CACERES U.C.R., HOSPITAL INFANTA SOFIA, SAN SEBASTIAN DE LOS REYES, MADRID, SPAIN References Disorders of Cortical Formation: MR Imaging Features Abdel Razek, A.Y. Kandell, L.G. Elsorogy, A. Elmongy, and A.A. Basett AJNR Am J Neuroradiol January : 4-11 Clinical and imaging features of cortical malformations in childhood R.J. Leventer, E.M. Phelan, L.T. Coleman, M.J. Kean, G.D. Jackson Neurology September 1, :715. A developmental and genetic classification for malformations of cortical development J. Barkovich, R. I. Kuzniecky, G. D. Jackson, R. Guerrini, and W. B. Neurology December 27, : Classification system for malformations of cortical development: Update 2001.Neurology, December 26, : J. Barkovich, R. I. Kuzniecky, G. D. Jackson, R. Guerrini, Adult-Onset Neurologic Dysfunction Associated with Cortical Malformations Woo Ho Cho, David Seidenwurm, and A. James Barkovich AJNR Am J Neuroradiol 20: , June/July 1999 Morphologic Characteristics of Subcortical Heterotopia: MR Imaging Study James Barkovich Page 26 of 27

27 AJNR Am J Neuroradiol 21: , February 2000 Page 27 of 27