Devic Syndrome is a rare neurological disorder that affects both the protective sheet that lines the spinal cord and the optic nerve of the eye. People that have Devic syndrome lose the fatty covering of the spinal cord (myelin) and experience eye pain due to an exaggerated inflammatory response that occurs in the eye. The resulting spinal cord damage is known as transverse myelitis and the resulting eye inflammation is known as optic neuritis. Devic syndrome is a severe neurodegenerative disorder that can lead to blindness, paralysis, and incontinence (loss of bowel or bladder control).
Devic syndrome is an autoimmune disorder that is considered by many scientists to be a form of multiple sclerosis , another neurodegenerative disease that affects the protective coating of the spinal cord called the myelin sheath. In Devic syndrome, the course of the disease is more rapid and severe. Symptoms typically observed in patients that have multiple sclerosis usually appear after symptoms associated with Devic syndrome, distinguishing the two neurodegenerative diseases. Devic syndrome is also known as Devic disease and neuromyelitis optica.
It is still controversial whether Devic syndrome is a variant of multiple sclerosis. It is considered by some scientists to be a variant of a disease caused by exposure to the varicella zoster virus that results in acute disseminated encephalomyelitis (ADEM).
Devic syndrome can occur spontaneously, or in conjunction with multiple sclerosis or systemic lupus erythematosus. It affects males and females equally. Devic syndrome is a rare disorder, affecting less than an estimated five persons per million population per year.
Causes and symptoms
Devic syndrome is a chronic and degenerative disorder that usually affects both eyes. The eyes develop diminished sensitivity to bright lights, color vision impairment, and diminished light reflexes. Approximately two-thirds of persons with Devic syndrome experience complete visual loss. The symptoms begin with significant loss of vision that precedes muscle weakness, ataxia (coordination difficulties and unsteady gait, or manner of walking), and numbness. Inflammatory sites of attack are usually the optic nerve chiasma, optic tract, and spinal cord. Usually, the optic neuropathy (damage to the optic nerve) is accompanied by severe transverse myelitis, which involves an acute inflammation of the spinal cord. The optic neuropathy usually happens before the transverse myelitis occurs, but in approximately 20% of patients it occurs in the reverse order.
Persons with Devic syndrome can also experience urinary, gastrointestinal, and sexual dysfunction. This occurs due to degeneration of the nerves that exit the spinal cord and serve the body's trunk and limbs. Patients with Devic syndrome rarely experience clinical signs that involve defects beyond symptoms arising from the spinal cord and optic nerve. There are also characteristic brain MRI scan findings including swelling and signal changes that are typically observed, as well as increased protein content in the cerebral spinal fluid.
Diagnosis is usually made by a neurologist and an ophthalmologist, by examining the eye and initiating several neurological exams including an MRI of the brain.
The neurologist and an ophthalmologist are the physicians that will be involved in making the diagnosis and providing follow-up treatment for persons with Devic syndrome. Patients that lose their eyesight will also require an occupational therapist that specializes in assisting individuals that become blind.
There is no cure available for Devic syndrome. Treatment, therefore, is based solely on lessening the symptoms and providing comfort care for individuals that are in the more advanced stages of the disease. Steroidal anti-inflammatory medications such as corticosteroids might be helpful and are commonly prescribed for patients with this disorder. There is no defined standard of treatment for the disorder.
Recovery and rehabilitation
Recovery from attacks manifested by acute inflammation is often variable. Devic syndrome is a chronic disease, often progressive, and complete rehabilitation is usually not observed, as with many neurodegenerative diseases.
Currently, the National Institute of Neurological Disorder and Stroke (NINDS) at the National Institutes of Health (NIH) are investigating how to repair damage to the central nervous system while restoring full strength to injured areas. As of mid-2004, there is currently a Phase III clinical trial to determine the effectiveness of plasma exchange in the treatment of acute severe attacks of inflammatory demyelinating disease in patients with degenerative neurological disorders who do not respond to intravenous steroid therapy. Although the study is no longer recruiting participants, anticipated results are not yet published.
The prognosis for individuals that have Devic syndrome is poor, as the disorder is eventually fatal for many patients. Isolated acute demyelinated encephalomyelitis (ADE) affects the optic nerve and the spinal cord in a similarly to Devic syndrome, but occurs after an infection or a common cold, and is distinct from Devic syndrome. ADE patients can fully recover, although many have associated permanent deficits, and in rare cases ADE can also be fatal.
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National Eye Institute (NEI), National Institutes of Health, DHHS. 31 Center Drive, Rm. 6A32 MSC 2510, Bethesda, MD 20892-2510. (301) 496-5248 or (800) 869-2020. [email protected] <http://www.nei.nih.gov>.
Bryan Richard Cobb, PhD