Pneumorrhachis

Pneumorrhachis refers to the presence of gas within the spinal canal (either intra- or extradural). It is rare.

Clinical presentation

Patients can often be asymptomatic ³.

Pathology

Etiology

Pneumorrhachis can result from a number of causes:

• trauma (traumatic pneumorrhachis): can occur in a variety of traumatic settings
  • traumatic pneumothorax
  • blunt chest trauma ⁵
    • subarachnoid-pleural fistula
  • skull fracture
  • iatrogenic / post surgical 
    • epidural anesthesia
    • thoracic / lumbar surgery
• non-traumatic  
  • spontaneous pneumomediastinum (e.g. from bronchial asthma, Hamman syndrome)
  • regional necrotizing fasciitis (rare)
  • marijuana smoking
  • cocaine snorting ¹¹                                                  

Treatment and prognosis

Patients with pneumorrhachis usually are managed conservatively. The entrapped gas occupying parts of the cerebrospinal compartment may cause syndromes of both intracranial and intraspinal hypertension, as well as hypotension as a consequence to either an increase or decrease of intracranial and intraspinal pressure ³.

Pneumorrhachis can in rare cases cause symptoms of cord compression and may even require decompressive surgery. Hence, rapid evaluation and diagnosis remain important ⁸.

History and etymology

The term pneumorrhachis derives from the Ancient Greek, πνεῦμα (pneuma) meaning air and ῥάχις (rachis) meaning spine. 

Differential diagnosis

Consider intradiscal gas from degenerative disc disease ¹². A posteriorly bulging disc containing gas, in particular, may appear intrathecal in location. Sagittal views are helpful in establishing location of gas.

See also

• lumbar epidural gas