Radiologic demonstration of syringobulbia. Report of 8 cases

Out of 75 syringomyelia cases, 8 had a syringobulbic extension. The cavity was demonstrated by magnetic resonance imaging (3 cases), syringography (3 cases), ventriculography (2 cases), and myelo-CT (2 cases). The cavities could be separated into 2 groups. In the first (5 cases) the cavity extended from the floor of the fourth ventricle, anterolaterally (3 cases) or anteriorly in the midline (2 cases). The communication with the fourth ventricle was usually wide. In the second group (3 cases), the syringobulbic cavity was located anteriorly; 2 of the 3 had no communication with the fourth ventricle and had an exceptional cranial extension (syringocephalia). In selected cases, invasive studies may help to recognize the connections of the cavities, and thus be useful in planning the surgical treatment.