Foramen magnum syndrome after iatrogenic cerebrospinal fluid leak during lumbar spine surgery: A series of two cases

Abstract

Foramen magnum syndrome (FMS) is a rare complication from lumbar spine surgery. Cerebrospinal fluid (CSF) leaks can be difficult to treat. FMS is a dangerous complication due to excessive distal CSF drainage from a dural tear or secondary to a “controlled” lumbar drainage. We present two cases of FMS after iatrogenic CSF leaks. Both patients underwent decompressive laminectomy as a part of the index surgery. Intraoperative dural tear was not identified in either case. A postoperative computed tomography (CT) myelogram ordered in view of the positional headaches indicated a CSF leak. A lumbar drain was placed, but both the patients worsened symptomatically. CT head in Case 1 indicated tonsillar ectopia within the foramen magnum, while that in Case 2 revealed a posterior fossa hemorrhage with fullness of the foramen magnum and profound hydrocephalus. Both patients were treated surgically. Additional corrective measures were also initiated to reverse the pathology. Both patients made a good recovery with resolution of symptoms. Development of neurological changes in a patient with CSF leak may indicate an acute intracranial process. Treatment of foramen magnum syndrome requires prompt realization of the underlying pathology and measures to cease or modulate the CSF drainage. The dangers of excessive distal CSF drainage, whether it is from a dural tear or from “controlled” lumbar drainage, should be considered.