Subacute delayed ascending myelopathy: not just a post-traumatic disorder

Abstract

Study design: Case report. Objectives: Subacute delayed ascending myelopathy (SDAM), also known as subacute post-traumatic ascending myelopathy, is a rare early neurological complication of spinal cord injury (SCI), and the aetiology, pathogenesis and optimal management of this condition are poorly understood. The radiological features together with the clinical picture appear to be the most useful. We aim to increase awareness and further characterise SDAM. Setting: Spinal Cord Injuries Unit, Royal North Shore Hospital, Sydney, Australia. Methods and Results: We report two cases with radiological findings consistent with SDAM, and review the literature. Only a small number of cases have been reported and importantly, we report the first case occurring following a non-traumatic SCI. There are several hypotheses regarding pathogenesis, with several factors in our cases implicating a vascular mechanism. Conclusion: There is a lack of data characterising SDAM, and ascending myelopathy in a stable SCI should alert the clinician. Importantly, we propose that SDAM is the appropriate terminology.

Venous hypertensive myelopathy associated with cervical spondylosis

“…Patients with SPAM usually suffer significant neurologic deterioration after a few days of clinical stability of after spinal cord injury with MR findings of extensive high-T2 signal, spanning more than three segments from the initial injured segment. Although the pathophysiology behind SPAM remains is still unknown, several recent case reports indicate the involvement of spinal venous drainage impairment and hypertension [8][9][10]. The following points support venous hypertension as a possible cause of SPAM: neurologic level of deterioration dose not correspond with the T2 high area; neurologic deficit as well as the MRI changes ease overtime; postural changes are often associated with the easing or worsening of symptoms; T2 flow voids on the dorsal surface of the cord.…”

“…Also, Auler et al reported a case of traumatic mediastinal hematoma caused by compression of the brachiocephalic vein, resulting in VHM, which resolved after the resolution of the mediastinal hematoma [12]. It is also probable that the pathophysiology of SPAM overlaps with that of spinal VHM, as Tan et al suggested that subacute delayed ascending myelopathy is a more appropriate terminology as it is not just a posttraumatic disorder [10]. These studies suggest that VHM can be developed by various causes even in the absence of vascular anomalies.…”

Subacute Posttraumatic Ascending Myelopathy

“…The prognosis with SPAM varies according to the level of ascent of myelopathy. Usually, there is a slight improvement of 1 or more levels below the maximally affected level in most cases 2,6,[10][11][12][13]15 . However, sometimes SPAM may be fatal if there is involvement of upper cervical cord or brainstem 8,10 with a mortality rate of approximately 10% 10,25 .…”

“…Hence, we reviewed the existing literature on this rare entity to elucidate and analyze SPAM. We found only 28 cases of SPAM after thoracolumbar injury that were reported in the literature 2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] . We report a case of SPAM occurring after T11/12 fracture-dislocation with rapid ascent of neurological level with sudden worsening after surgery.…”

Subacute Posttraumatic Ascending Myelopathy After Thoracolumbar Spinal Cord Injury

“…Many authors have assumed a posttraumatic thrombus of the great artery of Adamkiewicz as a possible cause of SPAM 5,7,15 . Most cases of SPAM have been reported with trauma in the TL region that is the territory of the great artery of Adamkiewicz.…”