Transverse Myelitis (TM) is a neurological disorder caused by inflammation of the spinal cord. This rare condition damages the myelin sheath that insulates nerve cell fibers, which disrupts communication between the nerves in the spinal cord and the rest of the body. The inflammation can cause a range of symptoms, including pain, weakness in the limbs, sensory changes, and bowel and bladder problems.
Mortality Rate of Transverse Myelitis
Dying directly from the acute inflammatory attack of Transverse Myelitis is uncommon. However, the condition can lead to life-threatening complications. Studies of U.S. veterans with TM over long periods found mortality rates between 9.4% and 10.8%. These figures do not mean a person has a 10% chance of dying from TM itself.
Fatalities are more often a result of secondary health problems that arise from the neurological damage. While the immediate focus is on managing acute symptoms, long-term survival is tied to managing these complications. For example, in one study, the most common causes of death were related to malignancy, other existing health conditions, and direct complications of TM.
Leading Causes of Death in Patients
One of the most immediate dangers is respiratory failure, but other serious complications can also lead to death. The leading causes include:
- Respiratory failure, which is a high risk when inflammation affects the upper spinal cord. Nerves that control the diaphragm and other breathing muscles can be disrupted, leading to severe breathing difficulties that may require mechanical ventilation.
- Blood clots from immobility due to paralysis. Deep vein thrombosis (DVT), where clots form in the legs, is a common concern. If a clot travels to the lungs, it causes a pulmonary embolism (PE), a medical emergency that can be fatal.
- Severe infections in patients with long-term disability. Paralysis can lead to pressure sores that become infected, potentially causing sepsis if the infection enters the bloodstream. Urinary catheters also increase the risk of urinary tract infections (UTIs) that can progress to sepsis.
- Autonomic dysreflexia, an overreaction of the autonomic nervous system to a stimulus below the level of injury. This condition, affecting patients with injuries above the mid-thoracic level, can cause a sudden spike in blood pressure, leading to stroke, seizure, or cardiac arrest.
Factors That Affect Survival Rates
A primary determinant of a patient’s prognosis is the underlying cause of the Transverse Myelitis. When TM occurs without a known cause, it is referred to as idiopathic. However, TM can also be a symptom of another underlying condition, such as Multiple Sclerosis (MS) or lupus. The prognosis can be more severe when TM is associated with Neuromyelitis Optica Spectrum Disorder (NMOSD) or a paraneoplastic syndrome, which is when the condition is triggered by a cancerous tumor.
The characteristics of the initial attack also play a role in the long-term outcome. A rapid and severe onset of symptoms, such as complete paralysis within a few hours, is often associated with a poorer prognosis compared to a more gradual progression. The extent of the inflammation, whether it affects part of the width (partial) or the entire cross-section (complete), can also influence recovery. Complete TM is more commonly associated with conditions like NMOSD and tends to result in more severe, lasting deficits.
The age of the patient at the onset of TM can impact survival rates. Elderly patients, for example, may have other pre-existing health conditions, or comorbidities, that can complicate their recovery and increase their risk of mortality. A study found that increasing age was associated with an increase in mortality.
Prognosis and Recovery Expectations
The outcome for individuals with Transverse Myelitis varies widely. A commonly cited, though historical, framework for recovery is the “rule of thirds”: approximately one-third of patients experience a good recovery with minimal or no lasting symptoms. Another third are left with a fair recovery with moderate deficits like walking difficulties. The remaining third experience a poor recovery, resulting in significant disability, which may include permanent paralysis.
The recovery process typically begins within one to three months after the initial attack, with the most significant functional improvements often occurring within the first six months. The healing process can continue for months or even years. The prognosis is considered less favorable for individuals who show little to no improvement within the first three to six months. Recovery often involves extensive physical and occupational therapy to regain strength and coordination.