Increased intracranial pressure is the current focus in the assessment and management of spontaneous CSF leaks, said Richard Lebowitz, MD, a sinus specialist and Assistant Professor of Otolaryngology at New York University Medical Center. Otolaryngologists need to recognize that a patient with a spontaneous CSF leak often has increased intracranial pressure and is very different from a patient with a leak due to an injury, he continued.
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May 2008Risk Factors
Certain patients are at increased risk of such leaks, said Dr. Lebowitz. The typical patient is an obese, middle-aged woman, he said. If you see a patient with those characteristics and clear fluid coming out of her nose, you would have a higher index of suspicion for a spontaneous CSF leak than you would with a patient with clear nasal drainage without those risk factors. The risk is further increased in patients who have a history of head trauma or prior sinus surgery, he said.
The endoscopic approach used in the study is the most appropriate in most cases. This is generally a more effective and less morbid surgical approach than repair via a craniotomy, Dr. Lebowitz said. Spontaneous leaks have a slightly greater recurrence rate for a good reason-the increased intracranial pressure. You have to reduce the pressure to prevent recurrence.
The fact that patients who have spontaneous leaks are more likely to have underlying elevated intracranial pressure necessitates that the otolaryngologist evaluate and potentially treat such patients in conjunction with a neurosurgeon, he said.
Leaks Not Confined to Nose
Otolaryngologists need to know that there are different types of CSF leaks, primarily spontaneous leaks and those that occur following a traumatic event such as sinus surgery, said Todd Kingdom, MD, Associate Professor of Otolaryngology and Director of Rhinology and Sinus Surgery at the University of Colorado Health Sciences Center in Denver, who was not involved in the study. They also should know that CSF can leak into the temporal bone or ear as well as the nose.
Dr. Kingdom agreed with Dr. Lebowitz about the risk factors associated with spontaneous leaks. Why that occurs isn’t entirely clear, he said. We know that intracranial hypertension can weaken bone and membranes that are already thin, and that this condition is more associated with obesity. The persistent elevated pressure can thin the bone of the skull base even further.
Approaches in Postoperative Shunts
Dr. Kingdom agreed with the investigators that a spontaneous CSF leak needs to have sound repair, including both accurate location of the defect and the steps involved in repairing it. Noting that the investigators discussed medical therapy and the use of shunts as ways to reduce intracranial pressure, Dr. Kingdom stressed that there are several methods of shunting. The most direct is the use of a lumbar drain for three to five days after surgery. A more permanent approach is a ventriculoperitoneal shunt. It’s the most invasive, but it’s the most definitive.