New perspectives in the microscopic structure of human dura mater in the dorsolumbar region.

BACKGROUND AND OBJECTIVES

The object of this study was to describe the three-dimensional structure of the dura mater by use of scanning electron microscopy.

METHODS

Microscopic dissection of the dura mater from four fresh cadavers (aged 70, 75, 76, and 80 years) 8-12 hours after death were investigated in three different planes (longitudinal, tangential, and transverse).

RESULTS

The external surface of the dura mater, facing the epidural space, consisted of a network of randomly oriented fine collagen fibers. The thicker elastic fibers (2 microns in diameter) were observed on the surface of the dura. In the inner part of the dura mater, there were very fine lamellae of collagen fibers, which were bundled into thicker (4-5 microns) layers. The dura mater consisted of 78-82 layers, each layer including 8-12 very fine lamellae.

CONCLUSIONS

The fibers of the dura mater do not run in a longitudinal direction and are not arranged in a parallel fashion. Cytoarchitecturally the dura mater is a laminated structure built up from well-defined layers oriented concentrically around the medulla spinalis.