The patient was a candidate for posterior dorsal pedicular screw fixation. However, according to the detection of intraspinal air, surgery was postponed. After one week of conservative treatment, the patient regained consciousness. Physicians repeated the neurological examinations. The patient presented with paraplegia and sphincter dysfunction, without any changes. On follow-up CT of the cervico-thoracic spine, there was no trace of intraspinal air. The operation was performed successfully, eight days post-trauma, by posterior fixation method. No PR-related complications were observed.

Discussion

The term PR was first used by Gordon and Hardman in 1977[7,8]. PR is a rare condition, characterized by the presence of air in the intraspinal canal, which is usually diagnosed incidentally while examining coincidental injuries and disease. It almost always presents in combination with the presence of air in other cavities and coincident underlying injuries and diseases. In addition, in this case, the mechanism of injury was accidental, without lacerations and wounds. Improved imaging technology has increased PR diagnoses[2]. The air could be detected using images, such as plain radiograph, magnetic resonance imaging (MRI), and computerized tomography (CT) scanning, the last of which is especially helpful[2,9].

Different etiologies and possible pathways of air entry into the spinal canal are presumed, and can be classified descriptively as primary, secondary, traumatic, non-traumatic, intradural, and extradural (epidural or subarachnoid)[2,3,8-13]. Iatrogenic PR can result from various surgical interventions, anesthetics, and certain diagnostic techniques[4,6,14]. Non-traumatic etiologies include vertebral degeneration, malignancy and its associated therapy, infectious diseases by gas-forming organisms, etc. [14,15]. PR secondary to traumatic causes is rare and includes head, cervical, thoracic, abdominal and pelvic injuries or combinations of different injuries, including spinal trauma[16-18]. Traumatic and subarachnoid PR alone is frequently associated with major trauma and believed to be a marker of severeinjury[6,8,10].In this case, the etiology appears secondary, with unknown cause.

PR is usually asymptomatic and clinically non-specific. It is a primarily radiographic diagnosis but not a clinical one. The air in the spinal cord does not tend to migrate, and usually is spontaneously reabsorbed into the bloodstream over a period of several days[2,19,20]. Interestingly, in our case, the air trap was observed in the cervical spine but the fracture detected in T11.

There are a few reported cases of patients reporting discomfort and sensory disturbances; PR patients are typically managed conservatively[6,12,21,22]. Failure to diagnose and treat PR early can delay recovery and worsen prognosis [12,23]. In this case as well as in others, no sensory disturbances were observed. Intraspinal air must be clearly differentiated from free intraspinal gas collections owing to degenerative, malignant, inflammatory, and infectious diseases by gas-forming organisms [9].

Spontaneous resolution occurs in most cases of epidural space PR, which permits conservative management[19,20,24].There is no standard guideline for the treatment of PR. PR is apparently associated with increased morbidity and mortality[2,12].Entrapped intraspinal air, in combination with a one-way air valve mechanism, might cause tension PR and pneumocephalus with nervous tissue compression, requiring intervention[2]. In our case, after few days, we checked again with CT and no any air trap was observed in the spinal cord.

If cerebrospinal fluid (CSF) leakage persists, this could be managed by serial lumbar puncture or lumbar drainage[2,25,26]. Fistulae pathways with other cavities might require surgical innervations [27-29].Prophylactic managementwith antibiotics is typically not recommended in cases of extradural PR and in patients with intradural PR without signs and symptoms of meningitis [9]. Other treatment modalities include transient high concentration oxygen therapy to achieve nitrogen washout, which is recommended in some articles[2,12,24,30].The management of patients with PR must be individualized according to associated pathologies, requiring inter- and multidisciplinary control [2]. In the present case, no CSF leaks were noted; we administered only oxygen therapy.

The use of inhalational nitrous oxide, in cases in which general anesthesia is required, is avoided because it induces the expansion of intracavitary gas volume and results in increased intracranial pressure, owing to its diffusion into the air-filled space. Also, pressurization of the oronasopharynx should be avoided, and alternative anesthetic techniques, such as intermittent positive pressure ventilation (IPPV) with transient high concentration oxygen, are the methods of choice, preventing an increase in the volume of any intraspinal and intracranial air and simultaneously promoting faster reabsorption of air [9,31].

Conclusion

PR is a rare clinical entity and caused by a multitude of sources. Early detection, proper neurological examination, and rehabilitation evaluation are crucial for the treatment of PR secondary to trauma accompanied by neurological symptoms.It is typically self-limiting, without further therapeutic consequences. Management is directed to associate pathologies, to enable adequate therapy.

Conflict of Interest

The authors have no conflict of interest.

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