Myelitis And Acute Transverse Myelitis

Inflammation of the spinal cord (myelitis) can result from several diseases. Poliomyelitis affects the cord's gray matter and produces motor dysfunction; leukomyelitis affects only the white matter and produces sensory dysfunction. These types of myelitis can attack any level of the spinal cord, causing partial destruction or scattered lesions.

Acute transverse myelitis, which affects the entire thickness of the spinal cord, produces both motor and sensory dysfunction. This form of myelitis, which has a rapid onset, is the most devastating.

Causes

Myelitis may result from poliovirus, herpes zoster, herpesvirus B, or rabies virus; disorders that cause meningeal inflammation, such as syphilis, abscesses and; other suppurative conditions, and tuberculosis; smallpox or polio vaccination; parasitic and fungal infections; and chronic adhesive arachnoiditis.

Certain toxic agents (carbon monoxide, lead, and arsenic) can cause a type of myelitis in which acute inflammation (followed by hemorrhage and, possibly,necrosis) destroys the entire circumference (myelin, axis cylinders, and neurons) of the spinal cord.

Acute transverse myelitis has several causes. It often follows acute infectious diseases, such as measles and pneumonia (the inflammation occurs after the infection has subsided), and primary infections of the spinal cord itself, such as syphilis and acute disseminated encephalomyelitis. Acute transverse myelitis can accompany demyelinating diseases, such as acme multiple sclerosis, and inflammatory and necrotizing disorders of the spinal cord such as hematomyelia.

Signs & Symptoms

Acute transverse myelitis usually begins with sudden back pain, followed by numbness and muscle weakness that start in the feet and move upward. Commonly, a beltlike tightness is felt around the chest or stomach at the level affected by the myelitis. People may have difficulty urinating. These effects may worsen over several hours or several days and may become severe, resulting in paralysis, loss of sensation, and loss of bladder and bowel control. The degree of disability depends on the location (level) of the inflammation in the spinal cord and the severity of the inflammation.

Diagnostic Tests

Diagnostic evaluation must rule out spinal cord tumor and identify any underlying infection.

White blood cell count may be normal or slightly elevated; cerebrospinal fluid analysis may show normal or increased lymphocyte and protein levels without isolating the causative agent.

Throat washings may reveal the causative virus in patients suspected of having poliomyelitis.

Computed tomography scanning or magnetic resonance imaging is useful to rule out spinal cord tumor.

Treatment

In myelitis, treatment is supportive and focused on relieving the patient's symptoms. An underlying bacterial infection requires appropriate treatment.