The spectrum of inflammatory demyelinating diseases (IDD) includes neuromyelitis optica, acute disseminated encephalomyelitis, optic neuritis, and transverse myelitis, all of which need to be differentiated from multiple sclerosis (MS). Mayo Clinic scientists have developed a test for an antibody to myelin oligodendrocyte glycoprotein (MOG) which can help to differentiate the former set of diseases from the latter disease (see: Mayo Clinic develops neuro test that distinguishes demyelinating diseases from MS). Below is an excerpt from the article announcing its availability:
Mayo Clinic has launched a first-in-the-U.S. clinical test that will help patients who recently have been diagnosed with an inflammatory demyelinating disease (IDD) but may be unsure of the exact disorder. Neurologic-related diseases commonly affect the brain, optic nerves and the spinal cord, and this new test can distinguish other IDDs such as neuromyelitis optica, acute disseminated encephalomyelitis, optic neuritis, and transverse myelitis from multiple sclerosis (MS). The test uses live cells to identify patients who are positive for an antibody to myelin oligodendrocyte glycoprotein (or “MOG,” for short)....[A Mayo spokesperson said the following:] "we have learned that if patients test positive for MOG antibodies, it generally indicates that it’s not classical MS,”....“And, more important, some MS treatments have been reported to worsen the disease of patients diagnosed with an IDD that is not classical MS.”
“While many IDDs that mimic multiple sclerosis are rare, correct and early diagnosis allows for early immunotherapy with immunosuppressants, rather than disease-modifying agents that are commonly used in treating MS,”....The researchers also found that persistence of the MOG antibody is associated with disease relapses, thus warranting relapse-preventing immunotherapy. “We’ve learned that if patients are positive for MOG antibodies, and they have an attack (such as optic neuritis), and they persistently remain positive [for the MOG antibodies] when tested six to 12 months later, they have a higher likelihood for a relapse,” says Andrew McKeon...., a clinical biochemist and co-director of Mayo’s Neuroimmunology Laboratory.
It thus appears that the availability of the MOG test may help to clear up some of the ambiguity in diagnosis of demyelinating diseases. Here is the current set of criteria that are used for the diagnosis of multiple sclerosis (MS) (see: MS Diagnosing Tools):
Criteria for a diagnosis of MS
At this time, there are no symptoms, physical findings or laboratory tests that can — by themselves — determine if a person has MS....In order to make a diagnosis of MS, the physician must:
* Find evidence of damage in at least two separate areas of the central nervous system (CNS), which includes the brain, spinal cord and optic nerves AND
* Find evidence that the damage occurred at two different points in time AND
* Rule out all other possible diagnoses.
In 2001, the International Panel on the Diagnosis of Multiple Sclerosis updated the criteria to include specific guidelines for using magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) analysis, and visual evoked potentials (EP) to speed the diagnostic process. These tests can be used to look for a second area of damage in a person who has experienced only one relapse.... — referred to as a clinically-isolated syndrome (CIS). A person with CIS may or may not go on to develop MS.