By: Chris Ratliff and reviewed by Jack Burks M.D.
It is hardly unusual to hear stories of people who have been misdiagnosed several times before finally being diagnosed with MS. Others remain in limbo for years, wondering if they will ever get a definite MS diagnosis. This is partly because there is no single diagnostic test to establish a definite MS diagnosis, and also because there are many diseases which manifest symptoms similar to MS. These are called MS mimics.
WHY MIMICS MATTER
Familiarizing yourself with MS mimics and the ways in which they compare to MS can demystify much of the diagnostic process. Sometimes, the process of elimination is the only way to a MS diagnosis. Therefore, the more you know about MS mimics, the quicker you and your doctor can eliminate them as possibilities. Today, with MS specialists advocating early, aggressive treatment, the sooner a MS diagnosis can be confirmed, the better.
"If you are diagnosed with MS, you want to be sure that the diagnosis is correct," states Dr. Jack Burks, Clinical Professor of Neurology at the University of Nevada School of Medicine and senior editor of the book Multiple Sclerosis: Diagnosis, Medical Management, and Rehabilitation. "Certainly, other diseases can look like MS, but the treatments are not the same."
AUTOIMMUNE DISEASES THAT MIMIC MS
Acute Disseminated Encephalomyelitis (ADEM) is a demyelinating, neurological disease characterized by inflammation of the brain and spinal cord. Symptoms may include headache, seizure, stiff neck, ataxia, optic neuritis, vomiting, weight loss, lethargy, delirium, and sometimes paralysis of a single limb or one side of the body.
ADEM differs from MS in that it is often clearly triggered by an immunization, or viral infection. The most common cause is prior measles infection, usually in children. ADEM runs a monophasic course, which means that there is one episode.
Systemic Lupus Erythematosus (SLE), is a chronic, inflammatory disease that may affect the skin, joints, blood and kidneys. Symptoms include achy, swollen joints, extreme fatigue, anemia, skin rash, sun or light sensitivity, hair loss, seizure, and Raynaud's phenomenon, where fingers turn white or blue in the cold.
Sometimes called the great imitator, lupus commonly displays symptoms associated with another disease, such as MS. Lupus and MS can be diagnosed simultaneously, although that is less common than being diagnosed with one disease, and then later, diagnosed with the other.
An antinuclear antibody (ANA) test can help to confirm a lupus diagnosis, but other diseases, including MS, can also produce positive ANA results. In addition, even a person who has lupus will not always produce positive results on this test. A urinalysis or kidney biopsy may be performed to check for signs of possible kidney problems. MRI, CT scan, echocardiography, x-rays, and other diagnostic criteria are also used. Sometimes, MS lesions on the spinal cord can be a distinguishing factor, or first-trimester miscarriages, which are quite common in women with lupus, but not women with MS.
Sjögren's Syndrome is a chronic disease in which white blood cells attack the moisture-producing glands. It is a systemic disease, which means that it affects the entire body. Symptoms include dry eyes and mouth, difficulty swallowing and speaking, fatigue, joint pain, decreased sensation, and numbness. Sjögren's can plateau, worsen, or go into remission, and some people will experience mild symptoms, while others will be greatly debilitated.
Nerve conduction velocity (NCV) tests can be helpful in differentiating between MS and Sjogren's because nerve damage in MS is central, but nerve damage in Sjögren's is peripheral. However, this is not always the case. Occasionally, Sjögren's affects the central nervous system, causing cognitive impairment and spinal cord involvement.
"Some researchers believe that Sjögren's syndrome is somehow linked to MS," Burks says. "But this opinion remains highly controversial."
Myasthenia Gravis (MG) is a disease in which weakness occurs when the nerve impulse responsible for initiating movement fails to reach the muscle cells. Individuals with MG have an increased risk of developing other autoimmune diseases.
MG symptoms tend to fluctuate throughout the day, often worsening at night. Droopy eyelids, facial weakness, impaired eye coordination, weakness of the limbs, neck, shoulders, hips and trunk muscles are all typical. Muscle fatigue is common, and heat, overexertion, or increased stress can aggravate this symptom. MG can occur at any age, although young women and older men are the most commonly affected. Those with MG experience no loss or change in sensation and they don't normally experience generalized fatigue. Instead, they experience localized fatigue in overtired muscles.
"A very specific test for MG is a blood test for serum antibodies to acetylcholine receptors," Burks explains. "Eighty percent of all patients with MG will have abnormally elevated serum levels of these antibodies."
Sarcoidosis typically appears between the ages of 20 and 40. Usually, the disease appears briefly and heals naturally. However, between 20 and 30 percent of sarcoidosis patients are left with some permanent lung damage, and in 10 to 15 percent of the patients, the disease can become chronic. Symptoms include dry mouth, excessive thirst and fatigue, skin rash, vision abnormalities, chronic arthritis, shortness of breath, enlarged lymph glands, cough and fever. A chest x-ray is one of the most helpful diagnostic tools.
INFECTIOUS DISEASES THAT MIMIC MS
Lyme disease (LD) is an infection caused by Borrelia burgdorferi, a bacterium carried by deer ticks. Untreated, the bacterium travels through the bloodstream, causing severe fatigue, a stiff, aching neck, tingling or numbness in the extremities, and facial palsy. The primary symptom is usually a rash that radiates from the tick bite. Diagnosis should be made on the basis of symptoms and evidence of a tick bite, not blood tests, which can often give false results if performed in the first month after infection.
Those who live or work in residential areas surrounded by tick-infested woods, or enjoy hiking, camping, fishing and hunting, or live in endemic areas are at increased risk for this disease.
Human T-cell lymphotrophic virus-1 (HTLV-1) is associated with progressive spinal cord dysfunction. Symptoms include spasticity, partial paralysis of the lower limbs, bladder and bowel incontinence, and impotence. HTLV-1 can be ruled out with a titer, which is a type of elevated antibody test. "HTLV-1 affects the spinal cord and does appear similar to primary progressive MS," Burks explains. "But HTLV-1 primarily occurs in the Caribbean, so it is important to ask about travel to endemic areas. Besides the Caribbean, these areas include Southern Japan and less commonly, the Pacific Coast of South America, Equatorial Africa and the Southern United States. HTLV-1 is also common among intravenous drug users."
Neurosyphilis, the advanced form of syphilis, can cause visual problems, cognitive changes, and sensory or motor tract dysfunction. As with HTLV-1, testing the production of antibodies can eliminate syphilis and neurosyphilis from the list of possible diagnoses. "Neurosyphilis is not as common as it once was," Dr. Burks explains. "This is because syphilis, the forerunner of neurosyphilis, is so readily treatable today."
VASCULAR DISEASES THAT MIMIC MS
Stroke symptoms include sudden trouble with vision in one or both eyes, sudden trouble walking, dizziness, loss of coordination, sudden severe headache, confusion, trouble speaking or understanding, sudden nausea, fever, vomiting or loss of consciousness.
"Strokes can be caused by bleeding in the brain or by blood clots that cut off the blood supply to an area of the brain," Burks explains. "The result is that neurons in the brain die. Major strokes cause very obvious losses in function and are unlikely to be confused with MS. However, smaller strokes can produce changes or loss in function that can look similar to a MS attack. Many people with MS have first been misdiagnosed with stroke."
Central nervous system (CNS) Angitis, an inflammation of the blood vessels of the brain, can produce headache, confusion, and other neurologic deficits that slowly progress.
Dural Arteriovenous Fistulas are abnormal structures of blood vessels along the spinal cord that deprive the spinal cord of blood, resulting in weakness, bladder and bowel changes, and sensory symptoms, all of which appear in a relapsing or progressive manner. MRI of the spinal cord or spinal angiography may be required to confirm diagnosis.
Binswanger's is a cerebrovascular disease usually seen in older patients with high blood pressure. Demyelination of the white matter surrounding the brain, similar to white matter lesions seen in MS, can appear with this disease.
Other diseases are occasionally confused with MS. These include fibromyalgia and vitamin B12 deficiency, muscular dystrophy (MD), amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease), migraine, hypo-thyroidism, hypertension, Beçhets, Arnold-Chiari deformity, and mitochondrial disorders, although your neurologist can usually rule them out quite easily.
Fibromyalgia involves pain and fatigue of the muscles, ligaments and tendons. Muscular pain can be shooting or throbbing. Burning, stiffness, fatigue, face and head pain, cognitive impairment, numbness, tingling, dizziness and impaired coordination are common. Changes in weather, hormonal fluctuations, stress or depression can all contribute to symptom flare-ups.
"Although fibromyalgia does mimic MS, it will not show up on an MRI or even be observable at an exam," Burks says. "Fibromyalgia is very non-specific."
Vitamin B12 deficiency may cause demyelination, numbness and tingling of the hands and feet, fatigue, weakness, and in extreme cases, change in mental status. "There is a theory that vitamin B12 can actually produce more myelin, so people with MS may assume that they need more of it," Burks says. "But B12 is only beneficial if you have a deficit to begin with."
A FINAL WORD.
"While MS may have many mimics, a neurologist can usually make a correct diagnosis early in the disease by taking a careful history, doing a complete neurological exam, looking at the MRI, and sometimes, evaluating the spinal fluid," Dr. Burks states. "If you are concerned about your diagnosis, you can discuss your concerns with your neurologist and possibly get referred for a second opinion from a MS expert at a comprehensive MS center. The Multiple Sclerosis Foundation can help you locate a MS center in your area."
(Last reviewed 7/2009)