Advanced

AJNR - American Journal of Neuroradiology

Published ahead of print on October 8, 2008
doi: 10.3174/ajnr.A1305

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: ajnr.A1305v1 ajnr.A1305v2 30/1/113    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Jissendi-Tchofo, P. Articles by Barkovich, A.J. Search for Related Content PubMed PubMed Citation Articles by Jissendi-Tchofo, P. Articles by Barkovich, A.J.

American Journal of Neuroradiology 30:113-119, January 2009
© 2009 American Society of Neuroradiology

PEDIATRICS

Pontine Tegmental Cap Dysplasia: MR Imaging and Diffusion Tensor Imaging Features of Impaired Axonal Navigation

P. Jissendi-Tchofo^a,b,c, D. Doherty^d, G. McGillivray^e, R. Hevner^f, D. Shaw^g, G. Ishak^g, R. Leventer^h and A.J. Barkovich^a

^a Neuroradiology section, Department of Radiology, University of California, San Francisco, Calif
^b Service de Neuroradiologie, Hôpital Salengro, CHRU Lille, Lille, France
^c Neuroradiology section, Department of Radiology, Erasme Hospital, Brussels, Belgium
^d Division of Genetics and Developmental Medicine, University of Washington, Children's Hospital and Medical Center, Seattle, Wash
^e Genetic Health Services, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Australia
^f Neurological Surgery/Neuropathology, University of Washington School of Medicine, Seattle Children's Hospital Research Institute, Seattle, Wash
^g Department of Radiology, Children's Hospital and Medical Center, Seattle, Wash
^h Department of Child Neurology, Royal Children's Hospital, Parkville, Australia

Please address correspondence to Patrice Jissendi, MD, Radiology Department, Erasme Hospital, Route de Lennik 808, B-1070 Brussels, Belgium; e-mail: jissendi{at}gmail.com

BACKGROUND AND PURPOSE: Malformations of the brain stem are uncommon. We present MR imaging and diffusion tensor imaging (DTI) features of 6 patients with pontine tegmental cap dysplasia, characterized by ventral pontine hypoplasia and a dorsal "bump," and speculate on potential mechanisms by which it forms.

MATERIALS AND METHODS: Birth and developmental records of 6 patients were reviewed. We reviewed MR imaging studies of all patients and DTIs of patient 3. Potential developmental causes were evaluated.

RESULTS: All patients were born uneventfully after normal pregnancies except patient 6 (in utero growth retardation). They presented with multiple cranial neuropathies and evidence of cerebellar dysfunction. Variable hypotonia and motor dysfunction were present. Imaging revealed ventral pontine hypoplasia and mild cerebellar vermian hypoplasia, in addition to an unusual rounded to beaklike "bump" on the dorsal surface of the pons, extending into the fourth ventricle. Color fractional anisotropy maps showed the bump to consist of a bundle of axons directed horizontally (left-right). The bump appeared, on morphologic images, to be continuous with the middle cerebellar peduncles (MCPs), which were slightly diminished in size compared with those in healthy infants. Analysis of the DTI was, however, inconclusive regarding the connections of these axons. The decussation of the MCPs, transverse pontine fibers, and longitudinal brain stem axonal pathways was also abnormal.

CONCLUSIONS: Our data suggest that the dorsal transverse axonal band in these disorders results from abnormal axonal pathfinding, abnormal neuronal migration, or a combination of the 2 processes.

This article has been cited by other articles:

				A. J. Barkovich, K. J. Millen, and W. B. Dobyns A developmental and genetic classification for midbrain-hindbrain malformations Brain, December 1, 2009; 132(12): 3199 - 3230. [Abstract] [Full Text] [PDF]