Congenital Brainstem Disconnection Associated with a Syrinx of the Brainstem

Abstract

We report a case of congenital brainstem disconnection including the second detailed autopsy. A full-term newborn presented with irreversible apnoea and died on the fifth day. MRI revealed disconnection of the brainstem. The autopsy included a series of transverse sections of the mesencephalon, medulla oblongata and bridging tissue fragments. A fragile tube walled by mature brainstem tissue could be reconstructed. It enveloped a cylinder of fluid within the ventral pons extending to the mesencephalon and the lower brainstem. The aqueduct was patent and outside the lesion. The basilar artery was represented by a tiny median vessel. The ventral and lateral parts of the posterior brainstem were surrounded by heterotopic glial tissue. The olivary nucleus was absent and the cerebellar dentate nucleus was dysplastic. Considering the maturity of the remaining parts of the pons, the onset of structural decline is likely to be close to the time of birth. Probable causes are progressively insufficient perfusion through an hypoplastic basilar artery, and obstructed venous drainage through an abnormal glial barrier surrounding the posterior brainstem. The morphological findings can be characterized as a syrinx, known from disorders in which brainstem or spinal cord are damaged by a combination of mechanical and circulatory factors.

Key words

brainstem disconnection - neonate - central cerebellar nuclei - basilar artery

References

• 1 Bednarek N, Scavarda D, Mesmin F, Sabouraud P, Motte J, Morville P. Midbrain disconnection: an aetiology of severe central neonatal hypotonia.  Eur J Paediatr Neurol. 2005;  9 419-422
• 2 Fink AJ, Englund C, Daza RA, Pham D, Lau C, Nivison M. et al . Development of the deep cerebellar nuclei: transcription factors and cellmigration from the rhombic lip.  J Neurosci. 2006;  26 3066-4076
• 3 Greitz D. Unraveling the riddle of syringomyelia.  Neurosurg Rev. 2006;  29 251-253
• 4 Harding BN, Boyd SG. Intractable seizures from infancy can be associated with dentato-olivary dysplasia.  J Neurol Sci. 1991;  104 157-165
• 5 Kobori JA, Herrick MK, Urich H. Arhinencephaly. The spectrum of associated malformations.  Brain. 1987;  110 ((Pt 1)) 237-260
• 6 Mamourian AC, Miller G. Neonatal pontomedullary disconnection with aplasia or destruction of the lower brain stem: a case of pontoneocerebellar hypoplasia?.  Am J Neuroradiol. 1994;  15 1483-1485
• 7 Martland T, Harding BN, Morton RE, Young I. Dentato-olivary dysplasia in sibs: an autosomal recessive disorder?.  J Med Genet. 1997;  34 1021-1023
• 8 MacCann E, Pilling D, Hesseling M, Roberts D, Subhedar N, Sweeney E. Pontomedullary disconnection: fetal and neonatal considerations.  Pediatr Radiol. 2005;  35 812-814
• 9 Milhorat ThH, Capocelli AL, Anzil AP, Kotzen RM, Milhorat RH. Pathological basis of spinal cord cavitation in syringomyelia: analysis of 105 autopsy cses.  J Neurosurg. 1995;  82 802-812
• 10 Murofushi K. Normalentwicklung und Dysgenesien von Dentatum und Oliva Inferior.  Acta Neuropathol (Berl). 1974;  27 317-328
• 11 Poretti A, Boltshauser E, Plecko B. Brainstem disconnection: case report and review of the literature.  Neuropediatrics. 2007;  38 210-212
• 12 Raspall M, Ortega-Aznar A, del Toro M, Roig M, Macaya A. Neonatal rigid-akinetic syndrome and dentato-olivary dysplasia.  Pediatr Neurol. 2006;  34 132-134
• 13 Robain O, Dulac O. Early epileptic encephalopathy with suppres-sion bursts and olivary-dentatedysplasia.  Neuropediatrics. 1992;  23 162-164
• 14 Saito Y, Kobayashi M, Itoh M, Saito K, Mizuguchi M, Sasaki H. et al . Aberrant neuronal migration in the brainstem of fukuyama-type congenital muscular dystrophy.  J Neuropathol Exp Neurol. 2003;  62 497-508
• 15 Saito Y, Hayashi M, Miyazono Y, Shimogama T, Ohno K. Arthrogryposis multiplex congenita with callosal agenesis and dentato-olivarydysplasia.  Brain Dev. 2006;  28 261-264
• 16 Sarnat HB, Benjamin DR, Siebert JR, Kletter GB, Cheyette SR. Agenesis of the mesencephalon and metencephalon with cerebellar hypoplasia: putative mutation in the EN2 gene - report of 2 cases in early infancy.  Pediatr Dev Pathol. 2002;  5 54-68
• 17 Singh V, Boesel CP, Baker P. Septo-optic dysplasia and dentato-olivary dysplasia in a case of 18q deletion/3p trisomy.  Clin Neuropathol. 2004;  23 28-33
• 18 Trinka E, Rauscher C, Nagler M, Moroder T, Ladurner G, Irnberger E. et al . A case of Ohtahara syndrome with olivary-dentate dysplasia and agenesis of mamillary bodies.  Epilepsia. 2001;  42 950-953

Correspondence