26th June 2023

Anterior Cord Syndrome

Distribution of motor and sensory loss in anterior cord syndrome of the cervical spinal cord.

Image Source: Dr D Chang – own work

Anterior cord syndrome is an incomplete spinal cord syndrome affecting the anterior two-thirds of the spinal cord. In general, an anterior cord syndrome manifests as bilateral motor paralysis below the level of the lesion, with associated bilateral loss of pain and temperature sense. Lateral horn involvement can cause an autonomic dysfunction, including anhidrosis, hypotension, neurogenic bowel, bladder, and sexual dysfunction.

There are two primary ‘sub-syndromes’ depending on whether the anterior horn cells are affected (anterior horn cell syndrome) or whether the vascular supply to the anterior cord is the aetiology of the syndrome (anterior spinal artery syndrome).

In anterior horn cell syndrome, there is involvement of the anterior grey matter horns of the spinal cord, causing ipsilateral or bilateral flaccid motor paralysis with atrophy and fasciculations. The aetiology is varied and includes:

• Infections: Poliomyelitis, West Nile virus
• Iatrogenic: Post-radiation myelitis
• Metabolic: Hexosaminidase A deficiency (aka lysosomal storage disorder), GM2 gangliosidosis (aka Tay Sachs disease)
• Hereditary: Spinal muscular atrophies

Anterior spinal artery syndrome is typically vascular in aetiology, with disruption of the anterior spinal artery or the great artery of Adamkiewicz from a thrombus, ruptured aortic aneurysm, aortic dissection, or vasculitis. Disruption of vascular supply, e.g. in severe hypotension or a cocaine associated vasospasm, can cause a similar presentation. Onset is abrupt with deficits occurring minutes to hours post insult. Clinical features may include radicular back or neck pain and acute flaccid paralysis with loss of pain and temperature and autonomic dysfunction. Symptoms may progress to bilateral spastic para/quadriparesis over days to weeks. Touch, proprioception, and vibration sense are preserved due to the sparing of the dorsal column medial lemniscus tracts.

Treatment involves management of the underlying cause, e.g. fluid/vasopressors for hypotension, as well as supportive therapies, including physiotherapy and occupational therapy, social and psychological support along with pressure area care, bladder catheterisation, venous thromboembolism prophylaxis and stress ulcer protection. Prognosis is poor and many patients do not recover motor, sensory or autonomic function.