Bariatric surgery can improve migraines, but can also cause a new type of headaches.

While being overweight doese not cause migraines, in those who do suffer with migraines there is an inverse relationship between person’s weight and the frequency and severity of migraine headaches. Weight loss, including that due to weight loss (bariatric) surgery, has been reported to reduce the frequency of migraine headaches and migraine-related disability. Obesity is also associated with headaches due to increased intracranial pressure (also called pseudotumor cerebri) and losing weight improves such headaches as well.

However, while bariatric surgery may improve migraines, in a small number of people it can cause a different type of headaches. This rare type of headache is caused by a spontaneous leak of cerebro-spinal fluid (CSF), the fluid which surrounds the brain and the spinal cord. Such leaks are common after a spinal tap or can be a complication of epidural anesthesia. Loss of CSF can cause severe headaches, which are strictly positional. They are severe in the upright position, sitting or standing, but quickly improve upon lying down.

A study of 338 patients who underwent bariatric surgery at the Cedars-Sinai Medical Center in Los Angeles detected 11 patients who developed a spontaneous CSF leak with severe headaches. Headaches started anywhere within three months and 20 years after surgery. Clearly, headaches starting 20 years later are not likely to be related to surgery, which suggests that this link between bariatric surgery and headaches is far from proven. Of these 11 patients, 9 improved with treatment. The typical treatment for a CSF leak is a “blood patch” procedure, which involves taking blood from the patient’s vein and injecting it into the area of the leak. When blood clots, it usually seals the leak and the headache improves within hours.