Dr. Ian Carroll's Resources

Dr. Carroll's resources: http://scnv.io/0NJ1

Low Pressure Headache (SIH)

​Spontaneous intracranial hypotension (SIH) is caused by spinal CSF leakage through the dural membrane, resulting in CSF hypovolemia and downward displacement of cerebral structures.
  • Extradural spinal fluid collection seen on spine MRI – this is usually due to dural tear from osteophyte (bone spur) – require hyperdynamic CT myelogram to show osteophyte
  • CSF venous fistula more common than extradural spinal fluid collection 
​Callen AL, Han L, Pisani Petrucci SL, Andonov N, Lennarson P, Birlea M, O'Brien C, Wilhour D, Anderson A, Bennett JL, Carroll IR. Patterns of clinical and imaging presentations in patients with spontaneous intracranial hypotension due to spinal cerebrospinal fluid venous fistula: A single-center retrospective cross-sectional study. Headache. 2024 Sep;64(8):939-949. 

Goddu Govindappa SK, Adiga CP, Kumar S, Goolahally LN, Kumar S. Spontaneous Intracranial Hypotension: A Review of Neuroimaging and Current Concepts. Indian J Radiol Imaging. 2023 Sep 16;34(1):128-138.
Occur on rising and/or later in the day

​Headache triggered by standing. In clinic, put patient in Trendelenburg (the body is laid supine, or flat on the back with the feet higher than the head by 15-30 degrees) 10 min, headache should resolve. Intracranial Spinal CSF leak, spontaneous or trauma (may be trivial) or valsalva. Ehlers-Danlos or joint laxity. Fragile dura. Brain MRI with contrast: dural thickening, brain sag. Do not confuse with Chiari malformation. Don't do LP routinely; if you do, use small needle, 24 gauge. Low pressure not always present: <60 mm. Cervical cord or thoracic cord. Identification of leak: CT and MR myelogram (intrathecal gadolinium, off label use). 
Leak in the Spinal Column, Most Often Low Cervical or Thoracic

Website for Patients
https://spinalcsfleak.org/

Key Factors
  • Postural, end-of-the-day, and Valsalva components to the headache are present
  • Joint hypermobility
Typical Characteristics
  • Orthostatic or gets worse at end of day. (Longer patient has SIH, the less likely there is a postural component.)
  • Majority of patients are awakened by headache in middle of night.
  • Headache is often exertional and worsens with Valsalva including coughing, sneezing, lifting, bending forward, straining, singing, or sexual activity.
  • Caffeine often works very well.
  • May be thunderclap in onset but not necessarily.
Other Symptoms
  • Tinnitus / sensorineural hearing loss
  • Abnormal hearing as if underwater
  • Neck pain, imbalance
  • Pain between shoulder blades
  • Blurred or double vision.
  • Cognitive dysfunction
  • Gait disturbances
Most common location is posterior, but pain can be centered anywhere in the head or face.
Bilateral more common than unilateral.

Risk factors: joint hypermobility, previous lumbar puncture, epidural or spinal anesthesia, known disc disease, or a personal or family history of retinal detachment at a young age, aneurysm, dissection, or valvular heart disease.

Physical Examination
  • Joint hypermobility
  • Spontaneous retinal venous pulsations indicative of normal CSF pressure are present in the eyes
  • Put patient in 5 degrees of Trendelenburg position for 5-10 minutes to see if that improves the headache and other symptoms.
Diagnosis
  • Brain MRI with gadolinium enhancement (normal in 30% of affected patients)
  • No consensus when the brain MRI is negative. Can do (1) CT with or without MR myelography, or (2) T2-weighted spine MRI. (No leak is found in about half of individuals with SIH.)
Treatment
Conservative measures don’t work very well. Even if a leak site hasn’t been identified, treat with a high-volume epidural CT-guided targeted blood patch with fibrin sealant. (Relief about a third of the time each time you do it)
Trendelenburg position: 15–30 degree incline with the feet elevated above the head.
​​CSF Leak Symptoms by Frequency

HEADACHE AND PAIN
  • Orthostatic headache – 92%
  • Neck / interscapular pain – 33%
  • Daily headache
  • 2nd half of the day headache
  • Exertional / valslva headache
  • Paradoxical orthostatic
OTHER
  • Nausea – 51%
  • Hearing/tinnitus/ear symptoms – 33%
  • Dizziness, vertigo – 18%
  • Visual symptoms
  • Altered consciousness
  • Extrapyramidal
  • Cognitive (frontotemporal)

Treatment of CSF Leak

  • Symptom management: bedrest / horizontal positioning; oral and IV hydration (temporary symptomatic benefit); oral and IV caffeine (temporary symptomatic benefit); oral theophylline (questionable benefit); steroids (questionable benefit + risks significant = rarely recommended); use of abdominal binder
  • Epidural blood patch: directed or non-directed
  • Epidural blood patch with fibrin glue sealant
  • Surgical repair 

Rebound Intracranial Hypertension (RIH)

A change in symptoms due to increased cerebrospinal pressure that occurs following treatment of SIH -- epidural blood patching, CSF venous fistula embolization or ligation or surgical dural repair
  • Frontal or periorbital headache
  • Worsened upright
  • Worsened in morning after sleep
  • Nausea, vomiting
  • Blurred vision
  • Transient papilledema (not common)
  • 24-48 hours after procedure (66-74%); 3-7 days after procedure (22%)
  • Resolves within 3 months (94%)
NON-DRUG TREATMENTS
  • Moderate sodium restriction / low sodium diet. ≤2,000–2,300 mg sodium/day is reasonable if there are no contraindications, while avoiding unusually salty meals. Water restriction not necessary.
  • Raise the entire upper torso about 20–30°, either with an adjustable bed, wedge, or recliner, rather than simply putting several pillows under the head. The latter can flex the neck, and significant neck flexion can actually impede jugular venous outflow,.Avoid lying completely flat. May sleep sitting.
  • Tea or other caffeinated beverage.
  • Therapeutic lumbar puncture.
  • Not usually recommended: optic nerve sheath fenestration (papilledema not usually present), shunt, stent
MEDICATIONS
  • First choice: acetazolamide -- starting dose (adults) 250 mg to 500 mg bid (may use tid), titrate up to 2000-4000 mg bid as tolerated
  • Second choice: methazolamide -- starting dose 25 mg bid, titrate up to 100-200 mg bid as tolerated (not renally excreted)
  • Third choices: topiramte, furosemide or bumetanide, HCTZ
  • Choice if patient is allergic: triamterine, spironolactone, ethacrynic acit

Cerebrospinal Fluid Venous Fistula

  • Direct connection between intrathecal CSF space and paravertebral vein in neural foramina, nerve root sleeve. Most common thoracic, but cervical, thoracic and sacral can occur.
  • CSF venous fistula actually more common than extradural fluid leak.
  • Diagnosis: Digital subtraction myelogram, lateral decubitus position, tilt table up to 15 degrees
Treatment
  • Blood patches low efficacy, does not provide permanent cure – only 1 of 40 improved
  • Surgical nerve root ligation
  • Embolization (Onyx) – most effective
​Bar chart illustrating distribution of clinical characteristics (green) and brain imaging findings (blue) in patients with
cerebrospinal fluid venous fistula. NOTE: Symptoms for CSF venous fistula are different from CSF leak.
Cerebrospinal Fluid Venous Fistula