Myelomeningocele, the Result of Rupture of the Embryonic Neural Tube
The IV stumbling blocks to truth:
The influence of fragile or unworthy authority.
The imperfection of the undisciplined senses.
Concealment of ignorance by ostentation of seeming wisdom.
SINCE the days of Von Recklinghausen1 it has been recognized that myeloschisis (an open portion of the neural tube) is the embryonic forerunner and basic lesion in the common form of myelomeningocele.2 The closed portion of the neural tube, particularly above the myelomeningocele, is dilated (hydromyelia). In many infants, this dilatation of the central canal increases as it passes toward the lesion, and there is progressive attenuation first of the roof plate, then of the floor plate, until the cord bifurcates into two imperfect cords3,4 (diastematomyelia) each with a dilated central canal. Each cord is rotated 90 degrees so that the anterior fissures face each other in the mid-line.5 The dilated central canal of each cord as it enters the myelomeningocele opens onto a flat mass of neural tissue representing “an exposed unclosed neural plate divided in half down the midline.”6 Caudal to the myelomeningocele these two plates come together again to form a spinal cord.
Solely on the basis of appearance, it has been assumed that the open, everted neural tube of the myeloschisis represents a failure of the tube to close.1,2 Morgagni,7 however, believed that “these watery tumors of the vertebrae” represented a disruption resulting from the pressure of fluid “descending in the tube of the spine” from the hydrocephalic head. Von Recklinghausen1 discredited Morgagni's hydromyelic theory. He refused to believe that hydrostatic pressure could accomplish such disruption, and because the neural tube was open, he asserted that it had failed to close.
Recently Patten,8 in a study . . .