Medical professionals agree that multiple sclerosis is a difficult disease to diagnose. Not only is there no single test that can conclusively diagnose MS, but many of its early symptoms closely resemble those of some other conditions. To further complicate matters, not everyone with MS experiences the most common symptoms of the disease.
If someone appears to be experiencing MS symptoms, one of the first things that physicians will attempt to do will be to rule out other possible diagnoses: that is, they will want to ensure that the patient in question does not have another condition that mimics MS. A variety of methods and tests can be employed to this end, including a comprehensive review of the patient’s medical history, a neurological exam, an MRI, blood tests, and a lumbar puncture. Some of the most common “MS mimicker” conditions that may be able to be ruled out this way include the following:
Lyme disease is a type of bacterial infection that is spread through bites from infected ticks. While the symptoms of Lyme disease initially resemble those of a mild case of the flu, it may progress to include MS-like symptoms such as fatigue, numbness or tingling in the hands and feet, short-term memory loss, and other cognitive problems. When attempting to determine whether or not someone has MS, it’s particularly important to rule out Lyme disease if the patient lives in, or has recently traveled to, an endemic area.
Conversion and psychogenic disorders
Also known as functional neurologic disorders, this group of conditions involves the conversion of psychological stress into a physical problem. In other words, people can experience a physical issue such as blindness or paralysis that has no apparent medical cause. A recent study published in the online journal Neurology revealed that, of a sample of 110 patients who had been “definitely” or “probably” misdiagnosed with MS, 11% actually had some form of conversion or psychogenic disorder.
Neuromyelitis optica spectrum disorder (NMOSD)
This inflammatory disease is similar to MS in that it attacks the protective coating known as myelin on the optic and spinal cord nerves. There are some crucial differences between the two conditions, however. In the early stages, NMOSD does not usually affect the brain (unlike MS), and its symptoms tend to be more severe (such as sudden vision loss, difficulty with bladder and bowel control, and uncontrollable vomiting). Obtaining an accurate diagnosis of NMOSD is extremely important, as misapplied MS treatments can actually make NMOSD worse. In order to differentiate the two conditions, a blood test called the NMO lgG antibody test can be used.
Another chronic autoimmune disease that is difficult to diagnose, lupus involves symptoms common to many other conditions, such as muscle pain, fatigue, and headaches. (A butterfly-shaped rash on the face is considered the hallmark symptom of lupus, but it only develops in about half of all lupus patients.) Like MS, lupus has no single diagnostic test. Instead, a rheumatologist will often make a diagnosis based on a number of laboratory tests and a careful analysis of characteristic lupus symptoms.
An arthritic-like disorder—though without the associated joint, muscle, and tissue damage—fibromyalgia is a chronic condition that is characterized by ongoing pain and tenderness in the body (people with fibromyalgia often compare the condition to having a constant muscle ache). Fibromyalgia and MS share some symptoms, including memory problems and numbness and tingling in the extremities. However, unlike MS, fibromyalgia will not reveal brain lesions on an MRI.
The autoimmune condition known as Sjögren’s syndrome displays many of the symptoms that autoimmune disorders tend to share, including fatigue and musculoskeletal pain, as well as a higher prevalence in women than in men. However, Sjögren’s syndrome is distinguished by the telltale signs of dry eyes and dry mouth, which are not usually present in MS cases.
A condition broadly characterized by the inflammation of the blood vessels, vasculitis can mimic MS quite closely. There are a number of different types of vasculitis, and the symptoms include blurred vision, joint pain, and tingling, numbness, or weakness in the limbs.
Fatigue and vision problems are the main symptoms that MS and the inflammatory autoimmune disease known as sarcoidosis share. However, sarcoidosis typically involves the growth of inflammatory cells in organs such as the lungs, lymph nodes, eyes, and skin, resulting in a host of symptoms—coughing or wheezing, swollen lymph nodes, and lumps, sores, or discolored patches on the skin—that are not typically associated with MS.
Vitamin B12 deficiency
Vitamin B12 plays an important role in the proper functioning of the central nervous system. Specifically, it metabolizes the fatty acids that the body requires to maintain the myelin sheath that coats and protects nerve fibers. Therefore, it makes sense that a vitamin B12 deficiency can cause MS-like symptoms, including numbness and tingling in the hands and feet, mental confusion, and general fatigue. Fortunately, all that’s needed to identify a vitamin B12 deficiency is a simple blood test.