What could be causing my constant intracranial pressure and intermittent pain that worsens when standing upright and improves when lying down?

Spontaneous Intracranial Hypotension: Your Symptoms Strongly Suggest CSF Leak

Your symptom pattern—constant pressure with intermittent pain that worsens when standing upright and improves when lying flat (especially prone)—is pathognomonic for spontaneous intracranial hypotension (SIH), not elevated intracranial pressure. This is a critical distinction because these conditions require opposite management approaches 1.

Why Your Symptoms Point to Low Pressure, Not High Pressure

The cardinal feature of intracranial hypotension is orthostatic headache: symptoms that worsen with upright posture and improve when lying down 1, 2. Your specific presentation includes several classic features:

• Worsening when standing upright is the hallmark of CSF leak and low intracranial pressure 1, 2
• Improvement when lying flat, especially prone occurs because horizontal positioning allows CSF to redistribute and reduces traction on pain-sensitive structures 3, 1
• Constant pressure sensation reflects ongoing brain sagging and meningeal traction from CSF volume depletion 4
• Intermittent pain may represent fluctuations in CSF pressure or positional changes 1

This pattern is opposite to elevated intracranial pressure, which typically causes headaches that worsen with lying flat, Valsalva maneuvers, and bending forward, and may improve when upright 5, 1.

Immediate Diagnostic Steps Required

You need urgent neuroimaging to confirm SIH and identify the CSF leak source 1:

First-Line Imaging

• Brain MRI with gadolinium contrast to look for diffuse smooth dural enhancement (pachymeningeal enhancement), brain sagging, subdural fluid collections, and venous sinus engorgement 3, 1
• Complete spine MRI to identify spinal epidural fluid collections and the leak site 3, 1

Critical Diagnostic Findings

The imaging will typically show 3, 4, 1:

• Diffuse smooth dural enhancement (most common finding)
• Downward displacement of the brain ("brain sagging")
• Subdural hygromas or hematomas
• Spinal longitudinal epidural collections (SLEC)
• Engorgement of venous sinuses

Important caveat: CSF opening pressure can be normal despite ongoing SIH and active symptoms, so normal pressure does not exclude the diagnosis 4.

Why This Diagnosis Is Being Missed

Several factors contribute to misdiagnosis of SIH 4:

• Mimics other conditions like migraine, cervicogenic headache, or postural orthostatic tachycardia syndrome
• Not all clinicians recognize that CSF pressure can be normal in chronic cases
• The orthostatic component may be subtle or overlooked in history-taking
• Imaging may be misinterpreted if radiologists are not specifically looking for SIH features

Treatment Algorithm Once Confirmed

Initial Conservative Management 1

1. Strict bed rest in supine position for 1-3 days
2. Aggressive hydration (oral or IV fluids)
3. Caffeine supplementation (oral or IV) 2
4. Analgesics as needed for symptom control 1

Definitive Treatment if Conservative Measures Fail 3, 1

1. Non-targeted epidural blood patch (EBP) as first-line intervention—typically 15-30 mL of autologous blood injected into epidural space
2. Targeted EBP if leak site is identified on imaging
3. Surgical repair if two EBP attempts fail or if there is an obvious structural lesion causing recurrent leaks 3

The case report demonstrates that surgical repair (laminectomy with direct dural repair) achieved definitive resolution after failed blood patches 3.

Life-Threatening Complications You Must Avoid

Untreated or prolonged SIH can lead to serious complications 3, 4:

• Cerebral venous thrombosis (CVT) occurs in approximately 2% of SIH cases and can cause intracranial hemorrhage, seizures, and death 3, 4
• Subdural hematomas from brain sagging and tearing of bridging veins 4
• Progressive neurological deficits including gait disturbance, ataxia, and parkinsonism 4
• Brain herniation in severe cases 4

The patient in the case report developed superior sagittal sinus thrombosis with life-threatening intracerebral hemorrhage requiring emergency surgery 3.

Next Steps

1. Request brain MRI with contrast and complete spine MRI immediately 1
2. Seek evaluation by a neurologist or neurosurgeon experienced in SIH 1
3. Maintain horizontal positioning as much as possible until definitive treatment 1
4. Monitor for warning signs of complications: sudden severe headache, focal weakness, vision changes, seizures, or altered consciousness 3, 4

The key message: Your symptom pattern of positional worsening (worse upright, better lying down) is inconsistent with elevated intracranial pressure and strongly suggests intracranial hypotension from CSF leak. This requires specific imaging and treatment that differs completely from elevated pressure management.