Intracranial Hypertension and POTS: Can You Have Both?

How Often Do IIH and POTS Show Up Together?

The closest data come from a 2023 report from 1 institution. Its team reviewed a database of patients with both connective tissue disorders and cerebral venous outflow disorders, where the veins that drain the brain don't empty well, and identified 86 people. Most were women (87%), 55% carried a diagnosis of Ehlers-Danlos syndrome, and the mean body mass index was 29.7. Aside from the venous problem and IIH, the abstract lists POTS in 55.8%, CSF leaks in 51.2% and dysautonomia in 45.3% (the abstract doesn't say how the leaks and raised pressure related in individual patients), and the authors describe "a rare but conserved clinical phenotype" (Midtlien, 2023).

With 1 referral group and no comparison group, it can't show how common IIH is in POTS.

What Is Idiopathic Intracranial Hypertension?

Intracranial hypertension means the pressure inside the skull is too high, and idiopathic means no cause has been found. The UK consensus guideline defines IIH by what's present and what's missing: "raised intracranial pressure, without hydrocephalus or mass lesion, normal cerebrospinal fluid (CSF) composition and where no underlying aetiology is found" (Mollan, 2018).

IIH occurs mostly in women and has "a striking association with obesity," though the guideline says the underlying cause isn't fully understood. It calls IIH typical in women of childbearing age with a BMI above 30, and atypical in anyone outside that group (Mollan, 2018). Most people in the 2023 cohort were non-obese (mean BMI 29.7), so a lower weight doesn't rule IIH out (Midtlien, 2023; Mollan, 2018).

Can IIH Cause Dizziness?

Dizziness is on the list of IIH symptoms. Along with headache, the guideline lists brief episodes of dimmed vision called transient visual obscurations, pulsatile tinnitus (a whooshing in time with your heartbeat), back pain, dizziness, neck pain, blurred vision, cognitive problems, nerve pain down a limb and side-by-side double vision. It adds that none of them is specific to IIH (Mollan, 2018). In the 2023 cohort, the abstract reports pressure headache in 98%, tinnitus in 92%, dizziness in 90% and cognitive problems in 69% (Midtlien, 2023).

Several of these overlap with POTS. Lightheadedness and blurred vision are in the POTS criteria, and headache and cognitive problems, including brain fog in POTS, are named among its other common symptoms (Vernino, 2021). That's why a symptom list can't separate the 2. A swollen optic nerve and a measured pressure point to IIH, while a sustained heart rate rise on standing points to POTS, and the orthostatic intolerance guide covers the standing side in more detail.

Headache often lasts. Over half of people with IIH still report headaches at 12 months, and the guideline describes a frequent mixed picture in which IIH headache sits alongside migraine, medication overuse headache, tension-type headache and headache from low CSF pressure, among others (Mollan, 2018).

How Is IIH Diagnosed?

IIH is a diagnosis of exclusion, built from several checks taken in order. If you have POTS and head pressure symptoms and want to know whether IIH is in play, the first check is an eye exam for papilledema. For someone with papilledema, a swelling of the optic nerve where it enters the back of the eye, the guideline says "all patients should have papilloedema confirmed" on an eye exam, along with an assessment of the risk to their vision. Blood pressure is measured first to rule out a dangerous rise. Next comes an urgent MRI of the brain within 24 hours, or an urgent CT if MRI isn't available, plus a scan of the brain's veins (CT or MR venography) to rule out a clot, a mass or blocked fluid flow. Raised pressure with a known cause, such as a clot in the brain's veins, isn't IIH, which is why imaging comes first. "Following normal imaging, all patients with papilloedema should have a lumbar puncture to check opening pressure and ensure contents are normal" (Mollan, 2018).

The guideline gives the diagnostic cut-off as an opening pressure above 25 cm of CSF, and adds 2 cautions: the pressure "should not be interpreted in isolation," and "clinicians debate the absolute LP opening value of 25 cm CSF as diagnostic of IIH" (Mollan, 2018). MRI can also show signs that point toward raised pressure, such as an empty or partly empty sella (the pocket that holds the pituitary gland), a twisting optic nerve or a widened sheath around it. The guideline says these "are not pathognomonic of IIH," meaning they hint at pressure without proving it.

All 4 checks Pressure alone

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Where Do Veins and Connective Tissue Fit?

Better venous imaging now shows "that many with IIH have anatomical abnormalities of the cerebral venous sinus system," the large channels that drain blood from the brain. The guideline adds that the degree of narrowing "does not appear to uniformly correlate with intracranial pressure or visual loss," so the guideline treats a narrowed sinus as a link whose role in the pressure isn't settled (Mollan, 2018). Venous sinus stenting is kept for highly selected patients with a raised pressure gradient across the narrowing and raised intracranial pressure whose usual treatment hasn't worked (Mollan, 2018).

The 2023 cohort adds a twist. Those patients had significantly lower opening pressures on lumbar puncture than classic IIH, yet reported the same headache severity and quality of life scores, which the authors read as a possible "underlying hypersensitivity to intracranial pressures and cerebral venous congestion" (Midtlien, 2023). With EDS in 55% of that group, it ties into the wider overlap between POTS and connective tissue, covered in POTS and EDS.

How Does Our Team Approach IIH With POTS?

IIH diagnosis and treatment belong with the neurologist and the eye team, because confirming it takes an eye specialist's exam, imaging and a lumbar puncture. In our team's view, someone with both should also have their POTS measured directly, with readings taken lying down and standing. Our team sees the fast heart rate in POTS as a compensation, the heart speeding up to protect brain blood flow when you stand.

Our team can measure heart rate, blood pressure, breathing and brain blood flow from lying to standing. The readings show whether flow drops while the heart rate and blood pressure look normal, as in OCHOS, whether breathing pulls CO2 down, as in hypocapnic cerebral hypoperfusion, and how well the brain's own blood flow controls are keeping up. When your history points toward raised pressure, we refer you on.

Medications for IIH are the prescribing doctor's call. The guideline's main drug is acetazolamide, and the Cochrane review it quotes found "modest benefits for acetazolamide for some outcomes" but "insufficient evidence to recommend or reject" it or any other current treatment. Weight loss is "the only disease-modifying therapy in typical IIH," meaning women of childbearing age with a BMI above 30 (Mollan, 2018).

When Do Vision Changes Need Urgent Care?

Sudden or worsening vision changes, or a headache with vision loss, need prompt care from an eye doctor or emergency department. IIH can threaten sight, which is why the guideline asks for every patient's papilledema to be confirmed along with an assessment of the risk to vision, regular eye exams while vision is threatened, and urgent attention for the fulminant form, "a precipitous decline in visual function within 4 weeks of diagnosis" (Mollan, 2018). A new vision change shouldn't wait for your next routine appointment.

IIH and POTS: FAQ