Spina Bifida: The Significance of the Level and Extent of the Defect to the Morphogenesis

Abstract

SUMMARY From a radiographic study of 601 infants with spina bifida, the author makes several important observations on the significance of the level and extent of the defect to the morphogenesis. The significance of the involvement of the thoraco‐lumbar junction is discussed. The author concludes that the site at which the bony laminar and pedicular malformations occur largely determines the extent of the dysraphia and, consequently, the degree of neurological damage and the ultimate prognosis. RÉSUMÉ Spina bifida: Signification du niveau et de Vextension des alterations pour la morphogenese D'après l'étude radiographique de 601 enfants atteints de spina‐bifida, l'auteur fait plusieurs remarques sur la signification du niveau et de I'extension des altérations pour la morphogénèse. La signification de l'implication de la malformation de la jonction dorso‐lombaire est discutée. Le lieu où se produisent les malformations osseuses des lames et des pédicules conditionne largement l'étendue de la malformation et par conséquent, le degré d'atteinte neurologique et le pronostic définitif. ZUSAMMENFASSUNG Spina bifida: die Bedeutung der Höhe und das Ausmass des Defektes aufdie Morphogenese Aus einer röntgenologischen Studie von 601 Kindern mit Spina bifida leitet der Autor mehrere Beobachtungen über die Bedeutung ab, welche die Höhe und das Ausmaß des Defektes aufdie Morphogenese haben. Die Bedeutung einer Beteiligung der thorakolumbaren Verbindung wird diskutiert. Die Stelle, an welcher die knöchernen laminären und pedicu‐lären Mißbildungen auftreten, bestimmt weitgehend das Ausmaß der Dysraphie und in der Folge den Schäeregrad der neurologischen Schädigung und schließlich die Prognose. RESUMEN Espina bifida: Significado del nivel y extensión del defecto sobre la morfogénesis Partiendo del estudio radiográfico de 601 niños con espina bífida, el autor hace varias observaciones sobre el significado del nivel y la extensión del defecto sobre la morfogénesis. Se discute el significado de la afectación de la articulacyón tóraco‐lumbar. La zona donde tiene lugar mayormente la malformación de láminas y pedículos, determina la extensión de la disrafia y, por consiguiente, el grado de lesión neurológica y en definitiva el pronóstico.

The dysraphic levels of skin and vertebrae are different in mouse fetuses and neonates with myelomeningocele

“…Also, the functional levels are mostly located within the lesion area and do not regularly coincide with the radiologic (skeletal) or with the anatomical (skin) defect. Similar observations are cited in the literature [13,[20][21][22][23][24]. For instance, Hunt et al [13,23] found the sensory level present at birth being the best predictive factor for long-term outcome in terms of mobility, continence, and overall disability rather than radiologic (skeletal), cutaneous, or motor activity level at birth.…”

Cervical Spinal Dysraphism

“…A spinal dysraphism commonly occurs at the thoracolumbar and lumbosacral levels, and should be investigated in two groups, designated as spina bifida occulta and spina bifida aperta [2]. A cervical myelomeningocele inside spina bifida aperta is a very rare condition; nevertheless, the results obtained from therapy appear to be better when compared to the results obtained from other spinal neural tube defects.…”

Comparative prenatal development of the spinal cord in normal and dysraphic dogs

“…This would appear as an abnormally different growth rate with the neuro ectoderm causing a thickening of the floor plate of the neural groove as reported by Patten (1953) and Barson (1970) when, instead, neuroepithelial cells are being drawn towards the midline with no increase in numbers.…”

“…A second theory on the development of NSD has been postulated by Patten (1953) and Barson (1970). They suggested that the morphologic changes observed in NSD may be attributed to abnormally different growth rates between the neuroectoderm and the mesoderm.…”

“…Another aspect of different growth rates concerns the formation of the head and tail folds (Barson, 1970). Disparities in the growth rates between neuroectoderm and mesoderm result in the formation of the head and tail folds during normal neurulation (Arey, 1965).…”