What is the likely diagnosis and management for a patient with a 6-week history of daily orthostatic pressure sensation in the head, which began concurrently with a lumbar procedure, and how should the patient be evaluated and treated given the suspicion of an iatrogenic cerebrospinal fluid (CSF) leak leading to intracranial hypotension?

Iatrogenic CSF Leak with Intracranial Hypotension Following Lumbar Procedure

Direct Recommendation

This patient almost certainly has intracranial hypotension from a CSF leak related to the lumbar procedure, and requires immediate brain and spine MRI with contrast followed by epidural blood patch, regardless of the proceduralist's opinion. 1

The temporal relationship (symptoms starting immediately after the procedure) and classic orthostatic pattern (daily pressure upon rising) are pathognomonic for post-procedural CSF leak, which occurs in 2-8% of spinal procedures. 1

Why the Pain Clinic is Wrong

The proceduralist's dismissal should be overridden based on the clinical presentation. Secondary intracranial hypotension from dural puncture is well-documented, and the 6-week duration with persistent orthostatic symptoms is diagnostic. 1, 2

• Post-procedural CSF leaks can occur even when the proceduralist believes the dura was not violated, as small punctures may not be immediately apparent. 2, 3
• Recent evidence shows that 4% of patients referred for "iatrogenic" leaks actually have spontaneous leaks triggered by the procedure, but the orthostatic pattern starting immediately post-procedure strongly favors true iatrogenic etiology. 3

Immediate Diagnostic Workup

Order MRI brain with IV contrast and MRI complete spine without contrast (optimized with 3D T2-weighted fat-saturated sequences) immediately. 1, 4

Brain MRI findings to look for: 1, 4

• Diffuse pachymeningeal (dural) enhancement
• Engorgement of venous sinuses
• Midbrain descent and brain sagging
• Subdural fluid collections or hematomas
• Pituitary gland enlargement with convex superior surface
• Effacement of basal cisterns (prepontine, suprasellar)

Spine MRI findings to look for: 1, 4

• Epidural fluid collections (spinal longitudinal epidural collection)
• Meningeal diverticula
• Dilated epidural venous plexus
• Subdural hygromas

Critical Diagnostic Pitfall

Do NOT perform lumbar puncture solely to measure opening pressure. 1 CSF pressure can be normal in 20-30% of intracranial hypotension cases, and a normal pressure does not exclude the diagnosis. 1, 5 The clinical presentation and imaging findings are more important than measured CSF pressure. 5

Management Algorithm

If MRI shows findings of intracranial hypotension: 1, 2

Proceed directly to epidural blood patch (EBP) at the suspected leak level or non-targeted lumbar EBP. 1, 2

• Early EBP (within weeks of symptom onset) has dramatically effective results for post-procedural CSF leaks. 6, 2
• Non-targeted lumbar EBP can be performed initially (up to two attempts) if the exact leak site is unclear. 1
• The patient should remain flat or in Trendelenburg position for 2-24 hours post-procedure. 1
• Clinical improvement typically occurs immediately to within days. 2, 7

If initial brain and spine MRI are completely normal: 1

Refer to a specialist center with multidisciplinary team (MDT) experience in intracranial hypotension for consideration of myelography. 1

• Up to 20% of brain MRIs and 46-67% of spine MRIs can be normal initially despite true CSF leak. 4
• Consider empirical non-targeted lumbar EBP (up to two attempts) even with normal imaging if clinical suspicion remains high. 1
• If symptoms persist after non-targeted EBP, proceed to CT myelography or dynamic digital subtraction myelography to localize the leak. 1

Myelography technique if needed: 1

• Decubitus CT myelography or lateral decubitus digital subtraction myelography are first-line techniques for leak localization. 1
• Once leak is identified, targeted EBP at the specific spinal level provides superior results. 7
• Patients may require multiple blood patches (1-5 treatments) for complete resolution. 7

Post-Treatment Monitoring

After EBP, monitor for 2-24 hours with bed rest and observe for complications including back pain, leg weakness, sensory changes, or urinary/fecal incontinence. 1

• Thromboprophylaxis should be considered during immobilization. 1
• Contact patient the following day if discharged to assess for concerning features. 1

Important Caveat About Rebound Headache

If the patient undergoes EBP and develops headache that WORSENS when lying down (opposite pattern), this indicates rebound intracranial hypertension, not treatment failure. 8

• Rebound headaches occur in 25% of patients 1-2 days post-EBP and are treated with acetazolamide, not repeat blood patches. 8
• Do not mistake this for persistent CSF leak, as additional blood patches will worsen the elevated pressure. 8

Rare but Serious Complication to Monitor

Intracranial venous thrombosis can occur as a complication of CSF hypotension, particularly if the patient is kept upright or if a lumbar drain is placed. 9

• Any patient whose headache intensifies after an initial plateau, persists beyond one week, or loses its orthostatic character should undergo urgent imaging for venous sinus thrombosis. 9
• This occurs due to venous stasis from cerebral vein dilation in response to CSF hypotension. 9