What is the cause and recommended management of orthostatic headache and back pain that worsen when upright and improve with recumbency?

Orthostatic Headache and Back Pain: Spontaneous Intracranial Hypotension

Your patient has spontaneous intracranial hypotension (SIH) until proven otherwise—a cerebrospinal fluid leak from the spine causing orthostatic headache and back pain that dramatically improve when lying flat. 1, 2

Immediate Diagnostic Confirmation

Order both of the following imaging studies immediately: 1, 2, 3

• MRI brain with IV contrast to identify:

  • Diffuse pachymeningeal (dural) enhancement
  • Venous sinus engorgement
  • Midbrain descent ("brain sag")
  • Pituitary enlargement
  • Ventricular collapse 2, 3

• MRI complete spine with fluid-sensitive sequences to localize the CSF leak source by detecting:

  • Epidural fluid collections
  • Dilated epidural venous plexus
  • CSF-venous fistula 2, 3

Critical Diagnostic Criteria to Confirm

The headache pattern must meet these specific criteria: 2, 3

• Absent or only mild upon waking or after prolonged lying flat
• Onset within 2 hours of becoming upright
• Improvement by >50% within 2 hours of lying flat
• Consistent timing pattern with each episode

Important pitfall: Normal CSF opening pressure does NOT exclude SIH—the problem is CSF volume insufficiency (hypovolemia), not elevated pressure. Clinical presentation and imaging findings trump measured pressure. 3 Approximately 20% of patients with active CSF leak have normal brain MRI findings. 3

Associated Symptoms That Strengthen the Diagnosis

Look for these accompanying features to increase diagnostic certainty: 1, 2

• Nausea and vomiting
• Neck pain or stiffness
• Pulsatile tinnitus or hearing changes (also predicts recurrence risk)
• Photophobia
• Visual disturbances
• Vertigo 2, 3

Differential Diagnoses to Exclude Before Confirming SIH

Perform an active standing test measuring supine heart rate and blood pressure, then at 1,3,5, and 10 minutes of standing: 3

Postural Orthostatic Tachycardia Syndrome (PoTS):

• Heart rate increase >30 beats per minute without blood pressure drop
• Critical caveat: A negative standing test does NOT exclude PoTS if clinical suspicion remains high 2, 3

Orthostatic Hypotension:

• Blood pressure drop >20 mmHg systolic and/or >10 mmHg diastolic on standing 2, 3

Cervicogenic Headache:

• Headache provoked by cervical movement (not just posture)
• Reduced cervical range of motion
• Myofascial tenderness 2, 3

Migraine:

• Headache triggered by physical movement (not posture alone)
• Presence of aura
• Vertigo rather than auditory symptoms 2, 3

Predisposing Risk Factors to Assess

Evaluate for connective tissue disorders that weaken dural integrity: 3, 4

• Joint hypermobility (Ehlers-Danlos syndrome, Marfan syndrome)
• Skin extensibility
• Family history of connective tissue disorders
• Spinal structural abnormalities (osteophytes, disc herniation) 3, 5

First-Line Treatment: Epidural Blood Patch

Early epidural blood patch (EBP) is the first-line treatment and should be performed as soon as possible after diagnosis. 2, 3 Initial non-targeted EBP is appropriate; reserve myelography for cases that fail to respond or have persistent symptoms. 3

Conservative measures while arranging EBP: 1

• Strict bed rest
• Aggressive hydration (2-3 L daily)
• Caffeine supplementation
• Antiemetics for nausea

Medication Precautions in SIH Management

Avoid or use with extreme caution: 1, 4

• Topiramate and acetazolamide (lower CSF pressure, exacerbate orthostatic symptoms)
• Candesartan and beta-blockers (reduce blood pressure, worsen postural symptoms)
• Indomethacin (potentially lowers CSF pressure)

Post-Treatment Monitoring

Follow-up schedule after EBP: 1

• 24-48 hours: Early review for complications
• 10-14 days: Intermediate follow-up
• 3-6 months: Late follow-up

Assess at each visit: 1

• Peak headache severity (0-10 scale)
• Time to severe headache onset after becoming upright
• Time able to spend upright before needing to lie down
• Cumulative hours upright per day

Post-treatment rebound headache may occur and represents secondary intracranial hypertension; if severe or worsening continues after 1-2 weeks, further clinical review is indicated. 1

Predictors of Recurrence

Patients at higher risk for recurrence include those with: 2

• Ventricular collapse on imaging
• Posterior fossa crowding
• Longer delay between symptom onset and treatment
• Pulsatile tinnitus

Slow mobilization is recommended following blood patch to avoid recurrence. 6 If initial improvement occurs followed by relapse, refer back to multidisciplinary team for discussion of further imaging or intervention. 1

Rare but Serious Complication

Cerebral venous thrombosis (CVT) occurs in approximately 2% of SIH cases and is life-threatening. 3 Evaluate with CT or MR venography if the patient develops thunderclap headache, focal neurological deficits, or seizures. 3