Gastric surgery for pseudotumor cerebri associated with severe obesity

Abstract

Objective: To study the efficacy of gastric surgery-induced weight loss for the treatment of pseudotumor cerebri (PTC).

Summary background data: Pseudotumor cerebri (also called idiopathic intracranial hypertension), a known complication of severe obesity, is associated with severe headaches, pulsatile tinnitus, elevated cerebrospinal fluid (CSF) pressures, and normal brain imaging. The authors have found in previous clinical and animal studies that PTC in obese persons is probably secondary to a chronic increase in intraabdominal pressure leading to increased intrathoracic pressure. CSF-peritoneal shunts have a high failure rate, probably because they involve shunting from a high-pressure system to another high-pressure zone. In an earlier study of gastric bypass surgery in eight patients, CSF pressure decreased from 353+/-35 to 168+/-12 mm H2O at 34+/-8 months after surgery, with resolution of headaches in all.

Methods: Twenty-four severely obese women underwent bariatric surgery--23 gastric bypasses and one laparoscopic adjustable gastric banding--62+/-52 months ago for the control of severe obesity associated with PTC. CSF pressures were 324+/-83 mm H2O. Additional PTC central nervous system and cranial nerve problems included peripheral visual field loss, trigeminal neuralgia, recurrent Bell's palsy, and pulsatile tinnitus. Spontaneous CSF rhinorrhea occurred in one patient, and hemiplegia with homonymous hemianopsia developed as a complication of ventriculoperitoneal shunt placement in another. There were two occluded lumboperitoneal shunts and another functional but ineffective lumboperitoneal shunt. Additional obesity comorbidity in these patients included degenerative joint disease, gastroesophageal reflux disease, hypertension, urinary stress incontinence, sleep apnea, obesity hypoventilation, and type II diabetes mellitus.

Results: At 1 year after bariatric surgery, 19 patients lost an average of 45+/-12 kg, which was 71+/-18% of their excess weight. Their body mass index and percentage of ideal body weight had fallen to 30+/-5 kg/m2 and 133+/-22%, respectively. In four patients, less than 1 year had elapsed since surgery. Five patients were lost to follow-up. Surgically induced weight loss was associated with resolution of headache and pulsatile tinnitus in all but one patient within 4 months of the procedure. The cranial nerve dysfunctions resolved in all patients. The patient with CSF rhinorrhea had resolution within 4 weeks of gastric bypass. Of the 19 patients not lost to follow-up, 2 regained weight, with recurrence of headache and pulsatile tinnitus. Additional resolved associated comorbidities were 6/14 degenerative joint disease, 9/10 gastroesophageal reflux disorder, 2/6 hypertension, and all with sleep apnea, hypoventilation, type II diabetes mellitus, and urinary incontinence.

Conclusions: Bariatric surgery is the long-term procedure of choice for severely obese patients with PTC and is shown to have a much higher rate of success than CSF-peritoneal shunting reported in the literature, as well as providing resolution of additional obesity comorbidity. Increased intraabdominal pressure associated with central obesity is the probable etiology of PTC, a condition that should no longer be considered idiopathic.

Figure 1. Mean cerebrospinal fluid pressure and weight before and 34 ± 8 months after surgically induced weight loss (p < 0.001, postoperative weight and cerebrospinal fluid pressure vs. preoperative values. (Reprinted with permission from Sugerman HJ, Felton WL III, Salvant JB Jr, Sismanis MD, Kellum JM. Effects of surgically induced weight loss on idiopathic intracranial hypertension in morbid obesity. Neurology 1995; 45:1655–1659.)

Figure 2. Correlation between urinary bladder pressure and sagittal abdominal diameter in 84 morbidly obese patients (filled square, men; filled circle, women) and 5 control nonobese patients (open square, men; open circle, women) with ulcerative colitis (r = 0.67, p < 0.0001). (Reprinted with permission from Sugerman HJ, Windsor ACJ, Bessos MK, Wolfe L. Abdominal pressure, sagittal abdominal diameter and obesity co-morbidity. J Int Med 1997; 241:71–79.)

Figure 3. Increased intracranial pressure secondary to increased intraabdominal pressure in an acute porcine model with the intraabdominal instillation of isosmotic polyethylene glycol and prevention of the increased intracranial pressure with median sternotomy and pleuropericardiotomy. (Reprinted with permission from Bloomfield GL, Ridings PC, Blocher CR, Sugerman HJ. Increased pleural pressure mediates the effects of elevated intra-abdominal pressure upon the central nervous and cardiovascular systems. Crit Care Med 1997; 25:496–503.)