by David Douglas

Last Updated: 2008-06-20 17:48:30 -0400 (Reuters Health)

NEW YORK (Reuters Health) – Overweight patients with chronic migraine appear to be at increased risk of idiopathic intracranial hypertension, Brazilian researchers report in the June issue of Cephalalgia.

"Our study is important," senior investigator Dr. Mario F. P. Peres told Reuters Health, "because a small but significant number of patients with chronic migraine had an increase in intracranial pressure. Obesity was a factor related to this finding."

Dr. Peres of Hospital Israelita Albert Einstein, Sao Paulo and colleagues note that chronic daily headache is associated with intracranial hypertension. However, most studies of headache and intracranial hypertension have involved refractory patients at tertiary headache centers.

In the current study, the researchers prospectively evaluated 61 treatment-naïve patients with chronic migraine. All of the patients met International Headache Society criteria for chronic migraine, and underwent cerebral magnetic resonance venography and lumbar puncture.

Overall, seven patients had intracranial hypertension. One patient had papilledema, while the other six patients did not, and was therefore excluded.

Of this group, only one subject had a normal body mass index, two were overweight and three were obese. All patients experienced significant relief of headache immediately following lumbar puncture that was sustained for a least 1 week.

After 1 month, three of the six patients had an increase in headache frequency and on re-examination, their cerebrospinal fluid (CSF) open pressure was elevated to previous levels.

Overall, the researchers found that BMI and CSF open pressure were significantly correlated. Moreover, more than half of all of the patients (55%) were overweight or obese.

Given this high prevalence of intracranial hypertension, similar to that seen in refractory patients, Dr. Peres said that "if a patient presents with a daily headache and is overweight or obese, we suggest a specific diagnostic evaluation with neuroimaging, and measurement of the cerebrospinal fluid pressure via a lumbar puncture should be performed."

Cephalalgia 2008;28:609-613.

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