New histopathological evidence for the relationship between hydromyelia and hydrocephalus following subarachnoid hemorrhage: An experimental study.

OBJECTIVES

Subarachnoid hemorrhage (SAH) is a serious pathology with a high death and morbidity rate. There can be a relationship between hydromyelia and hydrocephalus following SAH; however, this subject has not been well investigated.

MATERIALS AND METHODS

Twenty-four rabbits (3 ± 0.4 years old; 4.4 ± 0.5 kg) were used in this study. Five of them were used as the control, and five of them as the SHAM group. The remaining animals ( = 14) had been used as the study group. The central canal volume values at the C1-C2 levels, ependymal cells, numbers of central canal surfaces, and Evans index values of the lateral ventricles were assessed and compared.

RESULTS

Choroid plexus edema and increased water vesicles were observed in animals with central canal dilatation. The Evans index of the brain ventricles was 0.33 ± 0.05, the mean volume of the central canal was 1.431 ± 0.043 mm, and ependymal cells density was 5.420 ± 879/mm in the control group animals ( = 5); 0.35 ± 0.17, 1.190 ± 0.114 mm, and 4.135 ± 612/mm in the SHAM group animals ( = 5); and 0.44 ± 0.68, 1.814 ± 0.139 mm, and 2.512 ± 11/mm in the study group ( = 14). The relationship between the Evans index values, the central canal volumes, and degenerated ependymal cell densities was statistically significant ( < 0.05).

CONCLUSIONS

This study showed that hydromyelia occurs following SAH-induced experimental hydrocephalus. Desquamation of ependymal cells and increased cerebrospinal fluid secretion may be responsible factors in the development of hydromyelia.