Pneumorrhachis

Original Editor - Oluwafikunayomi_Wole-Bankole Top Contributors - Oluwafikunayomi Wole-Bankole

Introduction

Pneumorrhachis also known as Epidural emphysema is a rare condition characterized by intraspinal air or air in the epidural space as a result of traumatic, iatrogenic factors from surgery, anesthesia and diagnostic interventions or as a result of increased intrathoracic pressure associated with forced coughing from conditions such as bronchial asthma. Pneumorrhachis can be classified into epidural or subarachnoid depending on the location of the air in the spinal canal.

Aetiology

The causes of pneumorrhachasis is classified into iatrogenic, non-traumatic, or traumatic although traumatic cases are rare and traumatic pneumorrhachasis is usually associated with air in the subarachnoid space and is an indicator of severe injury. Cases of Traumatic Pnuemorrhachasis are often associated with neurological deficits and a few cases are as a result of stab injuries to the lower cervical spine.

Pathogenesis

The increase in the pressure between the alveoli and interstitial space which occurs during coughing can cause alveolar rupture, followed by air dissection along the bronchoalveolar sheaths and into the mediastinum. Air then passes through the path of least resistance into the mediastinum into the fascial planes of the neck. The lack of fascia barriers between the posterior mediastinum and the epidural space permits air to escape through the neural canal into the epidural space.

Epidermiology

Several cases are reported on the various presentations f the condition as it occurs in children in the case of 2 children having Pneumorrachasis as a result of pnuemomediastinum and also adults. The was a case of a 62 years old patient presenting with degenerative changes in the lumbar spine, including end plates and disc spaces, with intervertebral disc vacuum phenomenon (VP) with the CT showing intraspinal air in the epidural space at L5-S1 levels which compresses on the cauda eqina causing neurological symptoms. Pneumorrhachis was present in 5.8% of patients presenting with pneumomediastinum. This condition is also common in patients with forceful vomiting.

Clinical Presentations

This condition is often asymptomatic, although rarely it presents with symptoms such as pain, discomfort, neurological symptoms such as progressive muscle weakness as air in the spinal canal increases the pressure in the spinal cord and compresses the spinal cord Therefore, traumatic pneumorrhachis could be a possible cause of traumatic spinal cord compression. Some of these patients have co-morbidity such as Bronchial asthma and pnuemothorax. Air injected also can act as a space-occupying lesion and exert pressure on nervous structures within the spinal canal

Differential Diagnosis

• Tension pneumothorax
• Thoracic spinal fracture
• Pneumocephalus.

Diagnosis

Radiological investigations such as MRI and X-ray are used primarily for the diagnoses as intraspinal air is usually asymptomatic and clinically unspecific. Traumatic PR, especially subarachnoid, is an indicator of severe injury which is usually notable on the CT and therefore, CT scan is highly recommended in the diagnoses of PR.

Management

Medical and Surgical Management

Pnuemorrhachis which is spontaneous, asymptomatic and usually resolves it self therefore the management is usually conservative for this type of Pnuemorrhachis. Pnuemorrhachis is individualized and frequently requires multidisciplinary management, involving head, chest, and/or abdomen interventions depending on the presentations of the patient. Medical treatment approaches include the use of intravenous steroids (dexamethasone), administration of high concentrations of inspired oxygen to promote re-absorption of air, and hyperbaric oxygen therapy. The surgical management of this condition is dependent of the presentation as patients with pneumorrhachis have different presentations depending on the cause of pneunorrhachis. A case of reversible spinal cord and lower cervical root dysfunction caused by air dissection through a bronchopleural-epidural-cutaneous fistula

Physiotherapy Management

The role of physiotherapy in the management of pnuemorrhachis is dependent on symptoms and co-morbidity as each case presents with various causes. These include;

• To clear Airways
• Ensure proper breathing patterns
• Improve muscular strength
• Restore the patient to independent function concerning the symptoms presented
• Manage comorbidities and presentations such as Cancer, reduced respiratory function and asthma.