Spontaneous Intracranial Hypotension (SIH) is the Most Likely Diagnosis
Based on your 2-year history of constant positional pressure symptoms, audiovestibular complaints, and normal imaging, you most likely have spontaneous intracranial hypotension (SIH), which requires specialized CSF leak imaging that you have not yet received. 1
Why This Diagnosis Fits Your Presentation
Your symptom constellation is classic for SIH, despite normal standard imaging:
Positional pressure worsening: Your symptoms worsen when standing or lying flat on your back, with relief when lying on your stomach or left side—this orthostatic pattern is pathognomonic for CSF leak 1
Audiovestibular symptoms: Pulsatile tinnitus, regular tinnitus, muffled hearing, and ear pressure are well-recognized non-headache symptoms of SIH that occur in tandem with CSF leak 1
Dizziness and balance issues: These are common non-headache neurological symptoms in SIH patients 1
Pressure without severe headache: While most SIH patients have headache, some present predominantly with pressure sensation and other neurological symptoms 1
Normal standard MRI: Up to 20% of SIH patients have normal brain MRI, requiring specialized spinal imaging protocols to identify the CSF leak 1
Critical Diagnostic Gap in Your Workup
You have not had the appropriate imaging studies to diagnose SIH. Standard head CT and brain MRI do not evaluate for spinal CSF leaks. The 2023 multidisciplinary consensus guideline specifies that MRI-negative patients require 1:
- Lateral decubitus CT myelography (LD-CTM) as the gold standard for identifying spinal CSF leaks
- Lateral decubitus digital subtraction myelography (LD-DSM) as an alternative
- Ultrafast CT myelography (UFCTM) for detecting CSF-venous fistulas
These specialized studies must be performed in the lateral decubitus (lying on side) position to detect subtle leaks that are missed on standard imaging 1.
Why Other Diagnoses Are Less Likely
While your pulsatile tinnitus initially suggests vascular pathology, several factors argue against this:
Bilateral symptoms: Pulsatile tinnitus from vascular causes (atherosclerotic disease, dural AVF, arterial dissection) is typically unilateral, whereas you describe bilateral regular tinnitus and diffuse pressure 2
Positional relief pattern: Vascular causes of pulsatile tinnitus do not improve with specific body positions; your dramatic positional variation points to CSF pressure dynamics 2
Normal vascular imaging: If you had CT or MRI of the head, these would have identified major vascular abnormalities like paragangliomas, large AVMs, or significant carotid disease 2
Ménière's disease is excluded by your symptom pattern—Ménière's causes episodic vertigo attacks lasting 20 minutes to 12 hours, not constant pressure 1. Your symptoms are continuous and positional, not episodic 1.
Immediate Next Steps
You need urgent referral to a specialized center with expertise in spontaneous intracranial hypotension. The 2023 guideline emphasizes that SIH management requires a multidisciplinary team including neuroradiology, neurology, and interventional spine specialists 1.
Required Specialized Imaging
Request the following studies specifically 1:
- Lateral decubitus CT myelography (performed lying on your side, not supine)
- If LD-CTM is negative, proceed to MRI of entire spine with fat-suppressed sequences looking for spinal longitudinal epidural collections (SLEC)
- Consider ultrafast CT myelography if CSF-venous fistula is suspected
Treatment Options Once Diagnosed
If CSF leak is confirmed, treatment follows a stepwise approach 1:
- Conservative management initially: Bed rest, adequate hydration, caffeine supplementation
- Epidural blood patch (EBP): First-line interventional treatment, with follow-up at 10-14 days 1
- Targeted fibrin sealant patch: If leak location is identified and EBP fails
- Surgical repair: Reserved for refractory cases with identified leak site 1
Important Caveats
Post-treatment rebound headache: After successful CSF leak treatment, you may develop rebound intracranial hypertension causing temporary worsening of symptoms for 1-2 weeks—this is expected and self-limiting 1
Orthostatic rehabilitation: Given your 2-year history of limiting upright activity, you will likely need orthostatic rehabilitation to address deconditioning of both skeletal muscle and autonomic postural responses 1
Avoid certain medications: If you're taking migraine preventives, avoid topiramate, indomethacin, candesartan, and beta-blockers as these can lower CSF pressure and exacerbate SIH symptoms 1
If SIH Workup is Negative
Only if specialized CSF leak imaging is completely negative should you pursue alternative diagnoses:
Idiopathic intracranial hypertension (IIH): Can cause pulsatile tinnitus and pressure symptoms, though typically worsens when lying down (opposite of your pattern) 2
Superior semicircular canal dehiscence: Can cause pressure sensation and audiovestibular symptoms, diagnosed with high-resolution temporal bone CT 2
Persistent postural-perceptual dizziness (PPPD): A functional vestibular disorder that can develop after prolonged vestibular symptoms, but this is a diagnosis of exclusion after structural causes are ruled out with appropriate testing 3
The critical error in your care has been performing standard neuroimaging without the specialized spinal imaging protocols required to diagnose SIH. Your symptom pattern—particularly the dramatic positional variation with relief when lying on your stomach—is highly specific for CSF leak and demands proper evaluation before concluding "nothing is wrong" 1.