Anomalies of transverse and sigmoid sinuses associated with contracted jugular foramina.

Variations of the durai venous sinuses may present puzzling diagnostic and operative problems in the presence of thrombophlebitis. Such variations in sinuses of the posterior cranial fossa are usually associated with contracted jugular foramina and a small internal jugular vein. In the present study 214 sides of the bases of the macerated skulls were examined for the contracted jugular foramen and associated anomalies of the durai venous sinuses. In ten sides (4.67%) out of these an anomaly of the durai sinus of the posterior cranial fossa was found (two of right side and eight of left side). Out of these one case of right side was associated with the absence of groove for both transverse and sigmoid sinuses. All other cases were associated with the absence of groove for transverse sinus alone on the abnormal side. In seven cases out of these the jugular foramen was contracted on the abnormal side. The embryological basis and clinical significance of the anomalies of transverse and sigmoid sinuses is discussed here.