High pressure in skull may be rare sign of Ehlers-Danlos
IIH, condition marked by pressure buildup, reported in 3 US patients
A possible link has been suggested between Ehlers-Danlos syndrome (EDS) and idiopathic intracranial hypertension (IIH), a condition in which pressure builds up in the skull without an obvious cause.
In a case series, a team of U.S. researchers described three women with EDS who showed signs of elevated intracranial pressure, even though none had the typical swelling of the optic nerve — the nerve that carries visual information from the eye to the brain — that’s a hallmark of IIH.
These findings suggest that “IIH may be considered one of the rare manifestations of EDS,” the researchers wrote. The team noted that, while covering just three patients, “this is the largest series of cases linking IIH to EDS.”
Their report, titled “Idiopathic intracranial hypertension and Ehlers-Danlos syndrome: a case series,” was published in the Journal of Neurology.
EDS is a group of connective tissue disorders that cause overly flexible joints and fragile, stretchy skin that’s easily damaged. The condition can also affect bones, internal organs, and blood vessels, with symptoms varying widely by disease type. There are 13 types of EDS.
IIH, meanwhile, occurs when the cerebrospinal fluid (CSF) — the clear liquid that surrounds the brain and spinal cord— builds up, with the resulting pressure causing severe headaches, nausea, vision problems, and ringing in the ears.
Although headaches are common among people with EDS, those “attributable to IIH [are] exceedingly rare and reported only in a single case thus far,” the researchers wrote.
High pressure in skull found for 3 women of different ages
In this report, the trio of scientists, from institutions in Massachusetts and Pennsylvania, described three women with an EDS diagnosis who also showed features of IIH, pointing to a possible association between the two conditions.
The first woman, age 23, experienced persistent headaches that did not respond to standard treatments. Lumbar punctures, a procedure in which a small amount of spinal fluid is removed from the lower back to measure and relieve pressure, were conducted to treat her migraine. While this procedure brought relief, her symptoms kept returning until doctors placed a shunt to continuously drain excess CSF from her brain.
After that, her vision and optic nerves appeared normal, with no signs of raised pressure in her skull, according to the team.
The second woman, age 38, reported symptoms of worsening headaches, joint issues affecting her pelvis and shoulders, and sleep apnea — a condition that causes brief pauses in breathing during sleep and is known to increase the risk of IIH. This patient had undergone repeated lumbar punctures for headache relief.
Scans revealed several signs of IIH, including flattening of the nerve layers at the back of the left eye and narrowing of the veins that drain blood from the brain. Her vision and optic nerves appeared normal, although imaging revealed nerve cell loss, likely caused by long-term high pressure inside her skull, per the report.
The third woman, age 55, had lived with IIH for more than 30 years. She also had polycystic ovarian disease, a hormonal condition that has been associated with IIH.
Despite treatment, she developed vision problems, including reduced sight, narrowed visual fields, and decreased color perception. Eye imaging revealed thinning of the nerve layers at the back of the eye.
No swelling of optic nerve, a hallmark feature, seen in patients
The scientists noted a surprising absence of papilledema, or swelling of the optic nerve, that’s a hallmark feature of IIH.
“Interestingly, we did not observe papilledema in any of the cases that presented to us, with optic nerves in all three cases appearing healthy on dilated clinical examination,” the researchers wrote. The team did note that “two of the three [women] exhibited signs of optic nerve dysfunction.”
The team believes this may be because EDS makes the tissues surrounding the brain and spinal cord, known as the meninges, more flexible. This extra elasticity could allow the tissues to stretch and accommodate more CSF without immediately damaging the optic nerves, they noted.
“Without the pliable and accommodating meninges, all these patients may have experienced significantly more levels of optic nerve dysfunction,” the scientists wrote.
We believe that there may be a potential association between IIH [or idiopathic intracranial hypertension] and EDS.
The researchers noted that “it may be beneficial to carry out international collaborative studies and find the incidence of IIH in larger cohorts of patients with EDS,” adding that “the [disease-causing] mechanism and the exact incidence [occurrence] of IIH in EDS requires further study.”
Overall, though, the team said a link appears evident.
“We believe that there may be a potential association between IIH and EDS,” they wrote, though noting that it remains difficult to establish causality based on only three cases — especially given that two of the women also had other known risk factors for IIH.
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