Rapidly Injecting 10 MG of Intrathecal Fluorescein Caused No Neurologic Complications

Document Type

Conference Proceeding

Publication Date


Publication Title

J Neurol Surg B Skull Base


Background: Intrathecal fluorescein (ITF) is often effective in localizing nasal cerebrospinal fluid (CSF) leaks along the skull base under nasal endoscopy. Previous reports of seizures and paralysis have led to administration practices aimed at minimizing the risk of these potentially catastrophic neurologic complications. Since these early reports, surgeons have often reported injecting ITF slowly over a variable number of minutes, and that it should be diluted either in saline or patients' CSF. However, no study has assessed whether ITF administration duration or dilution alters the risks of these neurologic complications.

Methods: From September 2015 through August 2022, all patients undergoing ITF injection through lumbar drains for localization of possible or confirmed nasal CSF leaks were included. All patients had ITF administered by mixing 0.1 mL of 10% fluorescein (10 mg) with 3 to 5 mL of CSF, with no additional fluorescein dilution. The solutions were then injected through lumbar drains rapidly over 1 to 2 seconds. Patient demographics, CSF leak etiologies, and histories of seizures or cerebrovascular accidents were recorded.

Results: Sixty-one patients were included, mean age was 56.3 ± 15.6 years, and 82% were female. Fifty patients had CSF leaks repaired successfully, and 11 patients had negative explorations. CSF leaks were due to the following etiologies: idiopathic intracranial hypertension (76%), skull base tumors (10%), accidental trauma (8%), and surgical trauma (6%). Four patients had histories of seizure disorders, and five patients had remote histories of prior cerebrovascular accidents. There were no intraoperative or postoperative episodes of seizure, paralysis, or other neurologic complications.

Conclusion: Injecting 10 mg of ITF through lumbar drains rapidly and without true dilution resulted in no seizures, paralysis, or other neurologic complications in patients undergoing endoscopic exploration with or without nasal CSF leak repair.