1. Spontaneous Intracranial Hypotension
Headache Master School 2015
Spontaneous Intracranial Hypotension
Jong-Ling Fuh
Neurology, Taipei Veterans General Hospital
Schools of Medicine, National Yang-Ming University
Beijing, Oct 18, 2015

2. Spontaneous intracranial hypotension (SIH)
estimated prevalence: 1 per 50,000
Incidence: 5 per 100,000 per year
cardinal symptom: orthostatic headache
other associated symptoms
nausea/vomiting
Photophobia
hearing loss
tinnitus
Spontaneous intracranial hypotension (SIH) is a rare cause of secondary headache, with an estimated prevalence of 1 per 50,000 and an incidence of 5 per 100,000 per year in community-based and emergency department-based settings, respectively1
1. Schievink WI, et al. J Neurosurg 1998; 88: 243–246.
2. Rahman M, et al. Neurosurgery 2011; 69: 4–14.

3. 7.2.3 Headache attributed to spontaneous (or idiopathic) low CSF pressure
ICHD-2
Diffuse and/or dull headache that worsens within 15 minutes after sitting or standing, with at least one of the following and fulfilling criteria C and D:
1. neck stiffness, tinnitus, hypacusia
4. photophobia, nausea
At least one of the following:
1. evidence of low CSF pressure on MRI (eg. pachymeningeal enhancement)
2. evidence of CSF leakage on conventional myelography, CT myelography, or cisternography
3. CSF opening pressure < 60 mmH2O in sitting position
C. No history of dural puncture or other cause of CSF fistula
D. Headache resolves within 72 hours after epidural blood patching
Cephalalgia 2004; 24 (Supl 1):

4. 7.2.3 Headache attributed to spontaneous intracranial hypotension
ICHD-3β
Cephalalgia 2013; 33:

5. Brain descent → traction of pain-sensitive structures
CSF leakage
Asymptomatic in supine position

6. CSF Hypovolemia
SIH is caused by occult CSF leak→ CSF hypovolemia → brain sag, downward traction on leptomeninges and neural structures, compensatory venous engorgement, and enlargement of subdural/subarachnoid space1
The core pathophysiologic factor is a decreased volume of CSF rather than its pressure2
1. Schievink WI, et al. J Neurosurg 2005; 103: 608–613.
2. Mokri B, et al. Neurol Clin 2014; 32: 397–422.

7. Etiology
A history of trivial trauma in a substantial minority of patients
Weakness of the dural sac (meningeal diverticula)?
Stigmata of disorders of connective tissue matrix (Marfanoid habitus, joint hypermobility, skin hyperextensibility)?
Mokri B, et al. Neurology 2002;58:814-6
Schievink W, et al, Neurosurgery 2004;54:65-71

8. Meningeal diverticula
Neurosurgery 2004;54:65-71.

9. JAMA. 2006; 295:

10. Connective tissue laxity
Ehlers-Danlos syndrome Type II
hypermobility 
Neurosurgery 2004; 54:

11. Connective tissue laxity in SIH
Disproportionately long limbs: span/height>1.05 or upper/lower body<0.89
Liu FC et al. Cephalalgia 2011; 31:

12. Etiology
Stigmata of connective tissue disorders, especially dolichostenomelia, are common among SIH patients
Most SIH patients do not harbor mutations in FBN1 gene (classic Marfan syndrome), encoding fibrillin 1, or TGFBR2 gene (Marfan syndrome type 2, aka Loeys–Dietz syndrome type 2B), encoding TGF-β receptor 2.
約有1/5的病患有joint hypermobility，有約1/3的病患有dolichostenomelia
Trivial trauma resulting in rupture in pre-existing dural weaknesses. 韓國的研究找不出fibrillin 1 mutation. Schievink2008年的文章也找不出TGFBR2的mutation.
Schrijver I, et al. J Neurosurg 2002;96: Chung SJ, et al. Headache 2007;47:111-5.
Schievink WI, et al. J Headache Pain 2008;9: Liu FC et al. Cephalalgia 2011; 31:

13. Brain MRI with contrast
Subdural fluid collection
Enhancement of the pachymeninges
Engorgement of venous structures
Pituitary hyperemia
Sagging of the brain
=> SEEPS
Schievink WI. JAMA 2006;295:

14. Pituitary hyperemia Sagging of the brain Subdural hematoma
Enhancement of the pachymeninges
Engorgement of venous structures (venous distension sign)
After treatment
Pituitary hyperemia
Sagging of the brain

15. Brain descent
Incisural line: from anterior tuberculum sellae to confluence of great cerebral vein, straight sinus, and inferior sagittal sinus
Foramen magnum line: from inferior tip of clivus to inferior tip of bony base of foramen magnum
Iter >=1.8mm below insisural line
tonsil >=4.3 mm below foramen magnum line
Ann Neurol 1993;33:159-70
Acta Radiologica 2002;43:249-55

16. Brain descent
Before Tx
After Tx
31F

17. Detection of spinal CSF leakage
Radionuclide cisternography (ICHD-2)
Conventional myelography (ICHD-2)
CT myelography (ICHD-2)
Gd-enhanced MR cisternography/myelography
HeavilyT2-weighted MR myelography (HT2W MRM)
Mokri B. Neurol Clin 2004;22:55-74.
Schievink WI. JAMA 2006;295:
Schievink WI. Cephalalgia 2008;28:
Tsai PH et al. Cephalalgia 2007;27:929-34
Wang YF et al. Neuorology 2009;73:1892-8 17

18. Radionuclide cisternography
Indium-111, at intervals of 24 to 48 hrs. meningeal div may assume a similar appearance as CSF leaks. Exact level could not be localized.
Clin Neurol Neurosurg 2008: 110:

19. CSF leaks on CTM
Multiple thoracic CSF leaks associated with meningeal diverticula
CSF collection anterolateral to the thoracic spinal cord
Bilateral CSF leaks at the cervicothoracic junction extending into the paraspinal soft tissues
JAMA. 2006; 295:

20. CSF leaks on CTM
Bilateral cervicothoracic CSF leaks without an associated meningeal diverticulum
Left thoracic meningeal diverticulum with an associated CSF leak
Right thoracic meningeal diverticulum without an associated CSF leak
Cephalalgia. 2008, 28, 1347–1356.

21. CSF leaks on CTM
J Neurosurg 1998; 88:243–246.

22. Conventional spinal MRI
高長蘇承珊醫師
Limited diagnostic value!
Eur Neurol 2009; 61:

23. Conventional T2WI vs HT2W MRM

24. Conventional T2WI vs HT2W MRM

25. HT2W MRM vs CTM for SIH Kappa=0.71, p<0.001 Agreement=95%
Wang YF, et al. Neurology 2009; 73: 25

26. Before and after EBP HT2W MRM Before tx Axial CTM HT2W MRM s/p EBP
Conventional T2WI
s/p EBP 26

27. Gd-enhanced MR cisternography/myelography
Albayram S, et al. Am J Neuroradiol 2008; 29:

28. Gd-enhanced MR myelography/cisternography
►1.5T or 3T. T1WI with FS after intrathecal Gd inj.
►27 patients (18F/9M), mean age 45 (18-73)
►CSF leakage identified in 6/8 CSF rhinorrhea, 3/5 recur. bac. meningitis, and 9/14 SIH
Belgean study. Gd-enhanced MRM is gaining popularity, but the results should be interpreted with caution. Esp for lower T and LS leaks, which could result from LP. The evidence supporting such a view point will be mentioned in a minute.
Caveats:
Gd-containing contrast not approved for intrathecal use
Some “leaks” could result from LP
Vanopdenbosch LJ, et al. J Neurol Neurosurg Psychiatry 2011; 82: 28

29. Complications: subdural fluid collection
SDH in 20%, non-hemorrhagic fluid collection in 23%
SDH was almost male gender, recurrence of severe headache, and neurologic deficits
May cause herniation and deterioration of neurological status
T1WI
T2WI
Lai TS, et al. Cephalalgia 2007; 27:
de Noronha RJ, et al. JNNP 2003; 74:

30. Non-hemorrhagic subdural fluid collection

31. Acute SDH with midline shift

32. Bleeding into non-hemorrhagic fluid collections
SDE only
10 days later…

33. Neuroimaging Findings
In SIH patients, SDH displayed on initial and/or series of neuroimaging studies could be:
- acute, subacute or chronic hematoma, unilateral or bilateral
- recurrent SDH (acute expansion of a preexistent hematoma)
- bleeding into a non-hemorrhagic fluid collection

34. Cause of SDH in SIH Patients
The persistence of negative pressure within the subdural space elicits subdural hygroma in patients with SIH
In addition, tearing of bridging veins or bleeding from engorged veins in the subdural space produces SDH
Schievink WI, et al. J Neurosurg 2005; 103: 608–613.

35. A Cause of Nongeriatric SDH
A recent study suggests that spinal CSF leaks may be a frequent cause of nongeriatric chronic SDH
Spinal CSF leakage was proven in 7 (26%) of 27 consecutive patients 60 years of age or younger who underwent operations for chronic SDH
Hematomas were unilateral in 20 patients (74%) and bilateral in 7 patients (26%)
Beck J et al. J Neurosurg 2014; 121: 1380–1387.

36. Complications: cerebral venous thrombosis
2.1% (3/141) in SIH. 85% involve venous sinus
(literature): 11M/9F, age 39.5 years
40% (8/20) had a change in headache pattern
40% (8/20) had complications of CVT:
►Seizure in 5
►Venous infarctions in 3
►ICH in 3
►Dural AVF in 2.
Schievink WI, et al. Headache 2008; 48: Wang YF, et al. Cephalalgia 2007; 27:

37. To drain or not to drain, that is the question.
SIH is not as benign as previously thought.
Paradoxical herniation is a real concern.
Timing of drainage controversial.
Lai TS, et al. Cephalalgia 2007; 27: de Noronha RJ, et al. JNNP 2003; 74: Vogel TW, et al J Neurosurg 2010; 113:

38. Timing for Surgical Intervention
Uncal herniation => poor prognosis.
Early surgical intervention should be considered for those with SDH ≥ 10mm and decreased GCS (and CSF leakage adequately treated).
Chen YC, et al. Cephalalgia 2015 (in press)

39. Complications: cerebral venous thrombosis
2.1% (3/141) in SIH. 85% involve venous sinus
(literature): 11M/9F, age 39.5 years
40% (8/20) had a change in headache pattern
40% (8/20) had complications of CVT:
►Seizure in 5
►Venous infarctions in 3
►ICH in 3
►Dural AVF in 2.
Schievink WI, et al. Headache 2008; 48: Wang YF, et al. Cephalalgia 2007; 27:

40. Treatment
Bed rest, hydration, caffeine, steroid, aminophylline, and abdominal binder
Epidural blood patching (EBP)
►Treatment of choice
►Early EBPs helpful in the majority of patients
►Immediate and lasting effect
►Directed (targeted) vs non-directed (untargeted)
Transcutaneous fibrin sealant injection
Surgical repair
Schievink WI. JAMA 2006;295:
Wang YF, et al. Neurology 2009; 73:
Cho KI et al. Neurology 2011; 76:

41. Targeted EBPs vs blind EBPs for SIH
Korean study. EBP under fluoroscopy.
Targeted EBPs are more effective than blind EBPs (87.1% vs 52%, p<0.05).
Cho KI et al. Neurology 2011; 76: 41

42. Surgical treatment for CSF leaks
J Neurosurg 1998; 88:243–246.

43. Surgical treatment for CSF leaks
Neurosurgery Apr;58(4 Suppl 2):ONS

44. Take home message Cranial imaging: S-E-E-P-S
Detection of CSF leakage: HT2W MRM (non-invasive, sensitive)
Targeted EBPs better than non- targeted EBPs; periradicular leaks as a reasonable target.
SDH ≥ 10mm + decreased GCS => early surgical intervention
Jong-LingFuh,M.D.
Taipei Veterans General Hospital