Subacute post-traumatic ascending myelopathy (SPAM) is a rare, potentially fatal disorder characterized by progressive neurological deterioration in a surgically stabilized, post-traumatic spine. The deficit cannot be attributable to ongoing mechanical instability, syrinx formation or iatrogenic causes. To report the incidence and potential treatments of SPAM we performed a systematic review. 

The systematic search for medical literature on SPAM following the PRISMA guidelines was performed on Medline, Ovid, Cochrane, Embase and PubMed databases between 1969 and August 2021. The search term was (ascending myelopathy) and all articles reporting SPAM in English were included. Of the 904 abstracts identified for this search term, 18 articles were included for final analysis. Cases were reviewed and the findings summarized.

Within the 18 articles, a total of 39 cases were reported. It is estimated to occur in 0.4-0.7% of spinal cord injuries. The mortality rate is up to10% primarily due to respiratory compromise. It effects predominately male patients (71.9%) in the age group between 21 and 30 years (n=15/39; 38.9%). The latent period prior to onset ranges from 1 day to almost 3 months with the mean between 1 and 2 weeks. It can cause either partial or complete motor and/or sensory deficits. Patients typically describe pain or sensory changes above the level of the traumatic spinal cord injury. Pyrexia was described by five authors with no underlying cause found.

The typical MRI changes seen in SPAM is a central region of T2 weighted hyper intensity, with generalized cord expansion and occasionally cord surrounding lesions, most commonly proximal to the original injury. Fortunately, in long term there is potential for improvement in the neurological impairment. 

This systematic review shows that the incidence rate of SPAM is low but the mortality rate is high; up to 10%. There is no efficient way to predict the onset and there is no effective treatment of this condition. However, there is some evidence that monitoring CSF pressures following spinal cord injury this may help confirm the aetiology and suggest therapies such as drains or expansion duraplasty to reduce spinal cord pressures.