There are no laboratory tests or specific set of symptoms that definitively point to a diagnosis of MS, so confirming the diagnosis can be a complex process. The doctor will rule out other conditions that could be causing symptoms, including but not limited to:
Infections of the central nervous system (CNS)
Lyme disease, syphilis, progressive multifocal leukoencephalopathy (PML), HIV and human T-cell lymphotropic virus-1 (HTLV-1)
Inflammatory disorders of the CNS
Systemic lupus erythematosus, Sjögren’s syndrome, vasculitis, sarcoidosis and Behçet’s disease
Leukodystrophy (including CADASIL), hereditary cerebellar degenerations, hereditary myelopathy and mitochondrial disease
Metastases and lymphoma
- Vitamin B12 deficiency
Structural damage in the brain or spinal cord
Cervical spondylosis, tumor, herniated disc and Chiari’s malformation
Other non-MS demyelinating diseases
Neuromyelitis optica (NMO) and acute disseminated encephalomyelitis (ADEM)
Some of these diagnoses are easy to rule out with a simple blood test (e.g. vitamin B12 deficiency), while others, such as sarcoidosis, may require a biopsy; some are much rarer than others. It may be helpful to work with a physician who is familiar with these conditions and their warning signs in order to arrive at a correct diagnosis as quickly as possible – and to begin the appropriate treatment — whether you have MS or not.
Lyme disease is an illness caused by the organism Borrelia burgdorferi, a bacterium known as a spirochete that is carried by a deer tick. The spirochete can be transmitted to people or animals by the bite of a tick – with the first signs of Lyme disease developing within days or months. Sixty to eighty percent of those infected with Lyme disease get a large, reddish rash sometimes described as a bulls-eye. Other symptoms include a flu-like illness with fever, headache, stiff neck, and muscle and joint pains.
Lyme disease can cause delayed neurologic symptoms similar to those seen in MS, such as weakness, blurred vision caused by optic neuritis, dysesthesias (sensations of itching, burning, stabbing pain, or “pins and needles”), confusion and cognitive dysfunction, and fatigue. Lyme disease symptoms may also have a relapsing-remitting course. In addition, Lyme disease occasionally produces other abnormalities that are similar to those seen in MS, including positive findings on magnetic resonance imaging (MRI) scans of the brain and analysis of cerebrospinal fluid.
These similarities in symptoms and test results have led some people with MS to seek testing for the presence of antibodies to Borrelia, to determine if their neurologic symptoms are the result of Lyme disease or truly MS. The distinction is important because Lyme disease, especially when treated early, often responds to antibiotic therapy, whereas MS does not.
For more information about Lyme disease, consult the Lyme Disease Association or the Center for Disease Control. Read more about studies that examine overlap in diagnosis of Lyme disease and MS.
Systemic lupus erythematosus is a chronic, inflammatory autoimmune disorder that can affect the skin, joints, kidneys, lungs, nervous system and other organs of the body. It usually appears between the ages of 20 and 40, and is approximately 10 times more common in women than men; it occurs more frequently in blacks and Asians than in other groups.
The most common symptoms of lupus include skin rashes and arthritis, which are often accompanied by fatigue and fever. The disease course, which can range from very mild to quite severe, often includes alternating periods of relapse and remission. The most common symptoms of neurological involvement from lupus are migraine headaches, changes in personality and cognitive function, epileptic seizures, and occasionally stroke – which are not typical manifestations of MS. Occasionally patients with lupus develop transverse myelitis or optic neuritis; these may indicate the presence of a condition that is similar to but distinct from MS, called neuromyelitis optica, that requires different treatment.
For more information about the diagnosis and treatment of lupus, consult The Arthritis Foundation, The Lupus Foundation of America, the Lupus Research Institute or the National Institute of Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse.
Neuromyelitis optica (NMO) causes attacks of optic neuritis and transverse myelitis, as does MS.
- In MS, optic neuritis typically causes visual impairment in one eye at a time, while both eyes may be affected simultaneously in NMO.
- Transverse myelitis causes weakness and loss of sensation in the legs and, depending how high on the spinal cord the inflammation occurs, occasionally in the arms. Transverse myelitis can also affect bowel and bladder function. Transverse myelitis attacks tend to be more severe in NMO than in MS, causing more severe symptoms — although that is not always the case.
A new blood test that measures antibodies to aquaporin-4 detects NMO in about 70% of cases. This test may identify that a person has NMO even before he or she experiences all the symptoms that lead to a confident diagnosis.
The treatment options for NMO differ significantly from those for MS. The disease-modiyfing therapies that have been approved for use in MS are not effective in NMO. Acute attacks of NMO are generally treated with intravenous methylprednisolone. Following the initial episode, a combination of prednisone and azathioprine (or, on occasion, some other immune-suppressing medication) is used to prevent future attacks. No controlled clinical trials have demonstrated the effectiveness of any long-term treatment. Some recent research has suggested that plasma exchange may be an effective treatment for severe attacks that have not responded to intravenous methylprednisolone.
For more information about neuromyelitis optica, consult the National Institute of Neurological Disorders and Stroke (National Institutes of Health) or The Transverse Myelitis Association.
Acute disseminated encephalomyelitis (ADEM) is a brief but intense attack of inflammation in the brain, spinal cord and occasionally optic nerve that causes damage to myelin. Symptoms of ADEM come on quickly, typically beginning with encephalopathy including behavioral changes such as confusion or excessive irritability, and an alteration in consciousness (e.g., lethargy, coma). The damage to myelin may also cause neurological symptoms similar to those seen in MS such as visual loss in one or both eyes caused by optic neuritis, weakness and loss of coordination. ADEM may occur in association with a viral or bacterial infection, as a complication of inoculation or vaccination, or without a preceding cause. Children are more likely than adults to have ADEM.
ADEM is sometimes misdiagnosed as a severe first attack of MS since some of the symptoms of the two disorders may be similar. However, ADEM usually consists of a single episode or attack lasting weeks or months, while MS features many attacks over the course of time. Doctors will often use MRI to search for old and new lesions on the brain and spinal cord; old areas of damage suggest that the condition is ongoing and may be MS rather than ADEM. In the absence of old lesions, it is difficult to discriminate severe first attacks of what will eventually be diagnosed as MS from ADEM. For this reason, the physician carefully monitors the person with ADEM to see if a recurrence or progression suggests MS. Differentiating ADEM from MS is important because the treatment recommendations differ significantly; people with MS will usually require some form of continuing immune treatments while those with ADEM will not.
For more information about acute disseminated encephalomyelitis, click here and consult the National Institute of Neurological Disorders and Stroke (National Institutes of Health) or The Transverse Myelitis Association.