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Spinal CSF leak

Summary

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  • Spinal CSF leak is characterised by spontaneous or traumatic leakage of cerebrospinal fluid from the spinal dura
  • Presents with orthostatic headaches, neck pain, and neurological symptoms
  • Diagnosis relies on clinical presentation, imaging findings, and CSF analysis1

Pathophysiology

  • CSF leaks occur due to:
    • Dural defects or weakness
    • Traumatic injury to the spine
    • Iatrogenic causes (e.g., lumbar puncture, spinal surgery)
  • Results in intracranial hypotension and potential downward displacement of brain structures
  • Compensatory mechanisms include venous engorgement and subdural fluid collections

Demographics

  • Incidence: 5 per 100,000 per year
  • More common in females (2:1 ratio)
  • Peak age: 30-50 years
  • Risk factors:
    • Connective tissue disorders (e.g., Marfan syndrome, Ehlers-Danlos syndrome)
    • Bone spurs or osteophytes
    • Previous spinal surgery or intervention

Diagnosis

  • Clinical presentation:
    • Orthostatic headaches (worsening when upright, improving when supine)
    • Neck pain or stiffness
    • Tinnitus, hearing changes
    • Visual disturbances
    • Nausea and vomiting
  • CSF analysis:
    • Opening pressure typically low (<60 mm H2O)
    • Normal or slightly elevated protein levels
    • Normal glucose and cell count
  • Myelography:
    • Gold standard for localising CSF leaks
    • CT or MR myelography can be used

Imaging

  • MRI brain:
    • Diffuse pachymeningeal enhancement
    • Sagging of brain structures
    • Venous engorgement
    • Subdural fluid collections
  • MRI spine:
    • Extradural fluid collections
    • Meningeal diverticula
    • Nerve root sleeve cysts
  • CT myelography:
    • Contrast extravasation at leak site
    • High sensitivity for detecting small leaks
  • Digital subtraction myelography:
    • Useful for dynamic imaging of CSF flow
    • Can detect slow or intermittent leaks

panels-1

  • 70-year-old patient with orthostatic headaches and transient bilateral 6th nerve palsies. The patient had a multi-level thoracic laminectomy for a compressive arachnoid cyst many years prior.
  • CT myelography showed a rapidly filling small ventral epidural leak (red arrow).
  • More apparent on later phase imaging, the ventral leak was associated with a small osteophyte (blue arrow).

panels-1

  • A 70-year-old patient presented with tinnitus and dizziness.
  • MRI showed extensive superficial siderosis above and below the tentorium.
  • While the patient had no headache, given the distribution of siderosis, a CSF leak was suspected.
  • MRI of the spine showed a longitudinally extensive ventral epidural collection, indicating a CSF leak.

Treatment

  • Epidural blood patch (targeted if the leak is localised) with surgery for refractory leaks
  • Brain MRI signs of intracranial hypotension (dural enhancement, brain sag, venous engorgement) prompt the search for the spinal leak; superficial siderosis can be a clue

Differential diagnosis

Differential Diagnosis Differentiating Feature
Chiari malformation Cerebellar tonsillar descent below the foramen magnum without diffuse pachymeningeal enhancement or brain sag
Subdural haematoma (primary) Crescentic extra-axial collection with blood products but no pachymeningeal enhancement or brainstem sag
Diffuse dural disease (IgG4, neurosarcoidosis) Nodular or asymmetric dural thickening; no brain sag or engorged venous structures
CSF-venous fistula Myelogram shows filling of a paraspinal vein

  1. Callen et al. Algorithmic Multimodality Approach to Diagnosis and Treatment of Spinal CSF Leak and Venous Fistula in Patients With Spontaneous Intracranial Hypotension. 2022. AJR. American journal of roentgenology - Open in new tab. ↩