Temporary Lumbar Drain as Treatment for Pediatric Fulminant Idiopathic Intracranial Hypertension: Comment
We believe that a lumbar drain could become the interventional treatment of choice in patients with IIH. In general, cerebrospinal fluid (CSF) is produced at the rate of 15 mL/hr. Dr. Jiramongkolchai et al drained the first patient at the rate of 15 mL CSF/hr for 8 days; this was followed by 5 mL CSF/hr for 1 day and 3 mL CSF/hr for 1 day, for a total of 10 days. The first patient in their study was cured with a lumbar drain; resolution was confirmed by clamping the drain for a period of 24 hours and then measuring the pressure. Our observations are that patients who develop low-pressure headache in the setting of IIH also experience resolution of their IIH. The shortest duration of this headache was 48 hour, so it may be possible to drain patients for a shorter period of time than their first patient, which was 10 days. Importantly, they clamped the drain for 1 day and then measured pressure confirming that the pressure had returned to normal. Their second patient was not cured. The rate of drainage was only 11.1 mL CSF/hr for 4 days. We suspect that the explanation for failure of the lumbar drain in this patient was the fact that the CSF was not drained at a rate greater than it is produced.
In our report, we proposed that a database be created where patients with IIH subjected to lumbar drainage could be documented. In this way, we could establish the average duration of drainage of CSF at a rate greater than 15 mL CSF/hr that leads to resolution of the IIH. We suggested initially draining for a 24-hour period at a rate of at least 15 mL CSF/hr and then clamping the drain for a period of 12 hours and then measuring the CSF pressure. If it remains elevated, we advocated a further period of drainage for a more prolonged period of time. When the CSF pressure returns to normal, the lumbar drain could be removed. Our cohort of patients consisted of those treated with a lumbar drain and those who developed a low-pressure headache after a lumbar puncture or in the setting of a lumboperitoneal shunt. Twenty-nine of our 31 patients remained free of symptoms for up to 10 years (mean: 3.5 years). One patient had a recurrence at 4 months, whereas a second patient had a recurrence 5 years later.