Keeping men with intracranial hypertension in your sights

Greater vision loss from the disorder found in men

A new study shows that men are more likely to lose vision as a result of intracranial hypertension, or increased pressure in the brain, than women with the condition. Idiopathic intracranial hypertension (IIH) is a neurological disorder involving too much cerebrospinal fluid pressure, resulting in severe headaches, swelling of the optic nerves, vision loss, double vision, and a whooshing noise in the ears, according to Beau B. Bruce, M.D., assistant professor of ophthalmology and neurology, Emory University, Atlanta
The study, published in the October 15, 2008, issue of Neurology, found that men with the condition were twice as likely to experience vision loss as women. The condition itself is actually much more prevalent in women. “Ninety percent of cases occur in women,” Dr. Bruce said. “So men are somehow unusual. Why certain men would get this disorder isn’t clear because primarily it affects young, obese women.” With earlier studies suggesting that men don’t fare as well as women visually, investigators here wanted to take a closer look. “We had this very large database of patients that we’d collected over a 17-year period, so we thought we had enough patients to look closely at this,” Dr. Bruce said.

Symptomatic differences

Included in the retrospective study were 721 consecutive patients from Emory University, Wayne State University (Detroit), and Mississippi State University (Jackson, MS). Of these patients just 9% were men. When investigators reviewed the data they found that there were symptomatic differences between men and women with IIH. “Men tended to be less likely to present with a complaint of headache and more likely to initially complain of visual problems,” Dr. Bruce said. Just 55% of men initially complained of headaches versus 75% of women.
The results showed that 35% of men reported visual difficulties as their first symptom versus just 20% of women. Initial neuro-ophthalmological assessment showed that just 79% of men complained of headaches compared with 89% of women. Also, by last follow-up the vision assessment for men was considerably worse than for women, with the males twice as likely to have severe vision loss.
Investigators theorize that there may be differences in pain threshold between men and women, resulting in fewer reports of headaches from males than from their female counterparts. “This may lead into why men have worse visual outcomes if there really are these differences in symptoms,” Dr. Bruce said. “They don’t present as early or they don’t have typical symptoms as early to bring them to medical attention.” As a result, men may be at a later stage in the disease by the time they realize that there is a problem. “Papilledema causes insidious visual loss kind of like glaucoma does,” Dr. Bruce said. “So by the time the patient says, ‘Something isn’t right with my vision,’ typically he or she has experienced a significant amount of visual loss.”
These symptomatic differences may also keep men with IIH from seeking follow up. Dr. Bruce sees this as putting the onus on practitioners to follow these men more carefully. “If men really aren’t having headaches, then we need to keep following them carefully because they aren’t going to call you up with headache complaints like a lot of the women, who tend to have more symptoms,” he said. “There are some women that are the same way. They don’t get headaches for whatever reason and you have to be more careful with those patients as well.”

Making the apnea connection

Also important to look for in IIH patients is sleep apnea. There were difference between men and women here as well. Study results indicated that women were much less likely to have sleep apnea, with just 4% having this diagnosis versus 24% of men.
Investigators are unsure of what, if any, relationship there is between IIH and sleep apnea. “If IIH is a disease of people who are overweight, certainly sleep apnea is also a disease of people who are overweight,” Dr. Bruce said. “So maybe these diseases just keep each other company.” At the same time, he sees it as important to keep the specter of sleep apnea on the radar in these patients since it can portend poorer outcomes. “Sleep apnea can be a risk factor for worse outcomes because from a mechanistic standpoint, sleep apnea can cause increased intracranial pressure, especially when a person is asleep,” Dr. Bruce said.
There is also some thinking that sleep apnea in women may be under diagnosed. “In studies of how many men versus women in the general population have sleep apnea it’s usually about 50/50,” Dr. Bruce said. “So it could be that a lot of women in this study and a lot more of the men, too, had sleep apnea that was never diagnosed—that’s the problem with a retrospective study.”
Overall, since men with IIH are at higher risk for vision loss and do not usually have classic symptoms, Dr. Bruce recommends keeping a closer eye on them. “There’s no harm, no foul in carefully watching men with this disease because we’re worried about them,” he said. “There’s also nothing wrong with getting sleep studies on these patients because, quite frankly, they’re at risk for sleep apnea and it could make the disease worse.”

Editors’ note: Dr. Bruce has no financial interests related to his comments.

Contact information

Bruce: 404-778-5360, Bbbruce@emory.edu