Editors' Note: Association of Amount of Weight Lost After Bariatric Surgery With Intracranial Pressure in Women With Idiopathic Intracranial Hypertension

In their multicenter randomized controlled clinical trial of patients with idiopathic intracranial hypertension (IIH), Mollan et al. sought to determine the amount of weight loss necessary to achieve physiologic remission (intracranial pressure [ICP] ≤25 cm CSF). The investigators not only found that greater weight loss was achieved with bariatric surgery over community weight management but patients who underwent surgery experienced greater and more rapid reduction in ICP. Furthermore, only patients in the surgical arm achieved a fall in ICP to ≤25 cm, which was associated with a mean weight loss of approximately 24% from their baseline weight. Dr. Ramsamy and colleagues highlight that surgery was not associated with statistically significant improvement in visual outcomes or headache, which are the most disabling symptoms of IIH. In response, Dr. Mollan and their coinvestigators note the study was powered to demonstrate a treatment effect for the primary outcome of ICP reduction (as a biomarker of disease remission), rather than for secondary outcomes regarding visual or other symptoms of IIH. That said, the investigators admit there remains no consensus definition for clinical remission in IIH. Dr. Brenner also comments on the potential adjuvant use of caffeine in weight loss for patients with IIH and the benefits of optic nerve sheath fenestration when vision loss occurs. The investigators cite their original manuscript (published in JAMA Neurology), which reported a rapid and significant fall in ICP within 2 weeks of bariatric surgery. It is possible that acute hormonal changes after surgery such as a rapid rise in gut neuropeptide glucagon-like peptide-1 may have played a larger role in ICP reduction than weight loss alone.