Myelomalacia
Myelomalacia is a pathological softening of the spinal cord tissue resulting from inadequate blood flow, trauma, inflammation, or other injury to the spinal cord. The term literally means “soft marrow” and represents a stage of spinal cord damage where the tissue becomes necrotic (dies) and softens. This condition can result in permanent neurological deficits and appears on MRI as areas of abnormal signal within the spinal cord. Myelomalacia represents irreversible spinal cord damage and is associated with various underlying causes including compression, ischemia, and inflammatory diseases.
What is it?
Myelomalacia represents an end-stage pathological process in the spinal cord where neural tissue undergoes necrosis and liquefaction, eventually forming a cavity filled with fluid or soft, degenerated tissue. This occurs when the spinal cord sustains severe injury from which it cannot recover. The spinal cord, unlike many other tissues, has very limited regenerative capacity, so once myelomalacia develops, the damage is typically permanent. The softening progresses through stages: initial injury or ischemia leads to edema (swelling), followed by necrosis (tissue death), and ultimately cavitation where the dead tissue breaks down and is replaced by fluid-filled spaces.
Common causes of myelomalacia include chronic spinal cord compression (from severe spinal stenosis, large disc herniations, or tumors that compress the cord for extended periods), spinal cord infarction (stroke of the spinal cord due to blocked blood vessels), severe trauma to the spine, transverse myelitis (inflammatory condition affecting the spinal cord), and vascular malformations that disrupt normal blood flow to the cord. The cervical (neck) and thoracic (mid-back) regions are most commonly affected, though myelomalacia can occur at any spinal level. The extent of neurological deficit correlates with the location and size of the affected area—cervical myelomalacia can affect all four limbs and respiratory function, while thoracic or lumbar involvement typically affects the legs and bowel/bladder function.
Important to Know
Symptoms of myelomalacia depend on the spinal cord level affected and the extent of damage, but typically include progressive weakness or paralysis below the level of injury, loss of sensation (numbness, inability to feel temperature or pain), muscle wasting and spasticity, loss of bowel and bladder control, and in cervical cases, difficulty breathing or swallowing. Unlike acute spinal cord compression (which may be reversible if treated quickly), myelomalacia represents chronic, irreversible damage. On MRI, myelomalacia appears as abnormal signal intensity within the spinal cord—typically bright on T2-weighted images and sometimes showing cord atrophy (shrinkage) or cavitation. Treatment focuses on addressing any ongoing compression or underlying cause to prevent further damage, although the existing myelomalacia cannot be reversed. Management includes surgical decompression if there is ongoing compression, treatment of any inflammatory or vascular conditions, comprehensive rehabilitation including physical and occupational therapy to maximize remaining function, management of spasticity and pain, bladder and bowel management programs, and prevention of complications such as pressure ulcers and deep vein thrombosis. Prognosis depends on the extent of damage and the underlying cause, but significant neurological recovery is unlikely once myelomalacia has developed, making early recognition and treatment of spinal cord pathology critical to prevent this irreversible condition.