Pathogenesis, diagnosis and management of pneumorrhachis

Abstract

Pneumorrhachis (PR), the presence of intraspinal air, is an exceptional but eminent radiographic finding, accompanied by different aetiologies and possible pathways of air entry into the spinal canal. By reviewing the literature and analysing a personal case of traumatic cervical PR after head injury, we present current data regarding the pathoanatomy, clinical and radiological presentation, diagnosis and differential diagnosis and treatment modalities of patients with PR and associated pathologies to highlight this uncommon phenomenon and outline aetiology-based guidelines for the practical management of PR. Air within the spinal canal can be divided into primary and secondary PR, descriptively classified into extra- or intradural PR and aetiologically subsumed into iatrogenic, traumatic and nontraumatic PR. Intraspinal air is usually found isolated not only in the cervical, thoracic and, less frequently, the lumbosacral regions but can also be located in the entire spinal canal. PR is almost exceptional associated with further air distributions in the body. The pathogenesis and aetiologies of PR are multifold and can be a diagnostic challenge. The diagnostic procedure should include spinal CT, the imaging tool of choice. PR has to be differentiated from free intraspinal gas collections and the coexistence of air and gas within the spinal canal has to be considered differential diagnostically. PR usually represents an asymptomatic epiphenomenon but can also be symptomatic by itself as well as by its underlying pathology. The latter, although often severe, might be concealed and has to be examined carefully to enable adequate patient treatment. The management of PR has to be individualized and frequently requires a multidisciplinary regime.

Fig. 1

Axial cranial CT scans (corresponding soft-tissue and bone window setting) revealing severe head injury accompanied by traumatic internal pneumocephalus with air distributed prepontine, perimesencephally and intraventricullary accompanied by skull fractures of the sphenoid, left occipital and petrosal bone leading to PR

Fig. 2

Sagittal multiplanar reformatted spinal CT images (corresponding soft-tissue and bone window setting) demonstrating traumatic cervical PR

Fig. 3

Axial CT scans of the cervical spine (corresponding soft-tissue and bone window setting) showing extradural air collection within the ventral spinal canal