New Study Links Headaches to Bariatric Surgery
More than one-third of US adults (78.6 million people) are obese, according to the Centers for Disease Control and Prevention.1 In addition to heart disease, stroke, and type 2 diabetes, obesity is also a risk factor for certain types of headaches. In addition, obese individuals are much harder to treat successfully for their migraines and headaches globally.
With the rise of obesity around the world, bariatric weight-loss surgeries are becoming an increasingly common treatment option.2-5 However, researchers are just beginning to investigate the long-term side effects of these procedures.6 Know adverse effects include gastric dumping, surgical complications, and malnutrition.
Headaches: New Risk Factor
Published in Neurology, a team of doctors at Cedars-Sinai Medical Center in Los Angeles, California, reviewed records of patients being treated for spontaneous intracranial hypotension (SIH), a known cause of orthostatic headaches.7 These headaches occur when a patient is vertical, with the pain being relieved by lying down in a horizontal position.
SIH can occur for various reasons, the most common being a leakage of cerebral spinal fluid (CSF) at the level of the spine.8,9 Body weight is known to play a role in CSF pressure,10 and when the team discovered a group of SIH patients with histories of having weight loss surgery, they decided to investigate.
The doctors looked at the medical records of 338 SIH patients who had been treated over the last decade to see which patients had histories of weight loss surgery. They also looked at 245 patients with intracranial aneurysms, who were used as a control group.
They discovered that 11 SIH patients, or 3.3%, had had a bariatric surgery before suffering from SIH—7 had undergone a Roux-en-Y gastric bypass and 4 had been given a gastric banding procedure.
According to lead author Wouter I. Schievink, MD, the director of Microvascular Neurosurgery at Cedars-Sinai, these findings suggest that bariatric surgery could be a risk factor for developing SIH, "a previously unreported association."
"Although the mechanism for this association remains to be determined, there are several lines of evidence that possibly link bariatric surgery and SIH," wrote Dr. Schievink and colleagues.
Dr. Schievink and his team believe that weight loss after these procedures might partially explain the incidence of SIH in postoperative bariatric patients.
Body Weight and Cerebral Spinal Fluid
Previous studies have found evidence of a relationship between body weight, CSF pressure, and spinal CSF leaks. For instance, obese patients can suffer from idiopathic intracranial hypertension11 and decreases in craniospinal venous outflow. Doctors now know that body mass index (BMI) could have a small, yet significant relationship with opening pressure of CSF.12-14
According to Dr. Schievink, as obese patients suffer from chronic elevations in CSF pressure, the spinal dura could become attenuated, leading to an increased risk of spontaneous spinal CSF leakage. After bariatric surgery, a lack of epidural fat could cause a paucity of necessary blockage that would otherwise prevent this leakage from occurring.
The causes of SIH incidence could be more complex, though, with various pathophysiologic mechanisms playing different roles. This speculation seems possible especially for the 11 patients, whose given quantities of weight loss and postoperative time periods before SIH diagnosis were highly variable.
Weight loss after the procedure was from 25 to 98 kilograms (55 to 216 pounds) with a mean weight loss of 52.5 kg (116 lb). Time between surgery and SIH symptoms ranged from 3 months to as long as 241 months. A majority of the patients were under 50 months—the mean time interval being 56.5 months.
There are other explanations to consider, as well, such as the effects of malnutrition, a noted bariatric complication.15 Deficiencies in nutrients like Vitamins A and D could have an effect on CSF absorption, dural integrity, or even the regulation of CSF pressure, the researchers said. It should be noted that all but one of the patients in Dr. Schievink's study were given some form of multivitamin preparation after their respective surgeries.
There are also limitations in the study to consider. While the female preponderance of bariatric surgeries was represented well, the control group was approximately 8 years older. And the study group didn't reflect the greater population of bariatric patients, which range widely from 18 to 54 years of age.16 Another problem could be the fact that patients requiring CSF leak repairs were overrepresented, which may mean that the observed association is actually between bariatric surgery and CSF leaks rather than SIH.
"Further studies are necessary to help elucidate this relationship and find means of preventing the development of spontaneous intracranial hypotension after bariatric surgery. This would be of benefit to all patients with spontaneous intracranial hypotension, regardless of BMI."
There was no targeted funding for this study and the authors reported no conflicts of interest.