Timely and accurate diagnosis
There are many possible causes of neurological symptoms. When MS is considered as a potential diagnosis, other causes must be excluded — through the tools and tests outlined below — before an MS diagnosis is considered definitive. While this process of exclusion may be very rapid for some individuals, it can take a much longer time — with repeat testing — for others. Making the diagnosis of MS as quickly and accurately as possible is important for several reasons:
- People who are living with frightening and uncomfortable symptoms want and need to know the reason for their discomfort. Getting the diagnosis allows them to begin the adjustment process and relieves them of worries about other diseases such as cancer.
- Since we now know that permanent neurological damage can occur even in the earliest stages of MS, it is important to confirm the diagnosis so that the appropriate treatment(s) can be initiated as early in the disease process as possible.
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. The doctor uses several strategies to determine if a person meets the MS diagnostic criteria. 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 (also called an attack or exacerbation) of MS-like symptoms — referred to as a clinically-isolated syndrome (CIS). A person with CIS may or may not go on to develop MS. The criteria (now referred to as The Revised McDonald Criteria) were further revised in 2005 and again in 2010 to make the process even easier and more efficient.
Tools for making a diagnosis
Medical history and neurological exam
- Takes a careful history to identify any past or present symptoms that might be caused by MS.
- Gathers information about birthplace, family history, environmental exposures, history of other illnesses and places traveled that might provide further clues.
- Performs a variety of tests to evaluate mental, emotional and language functions, strength, coordination, balance, reflexes, gait, vision, and the other four senses.
In many instances, medical history and neurological exam provide enough evidence to meet the diagnostic criteria. Other tests are used to confirm the diagnosis or to identify other possible causes of the symptoms or neurological exam findings.
While there is no definitive blood test for MS, blood tests can rule out other conditions that cause symptoms similar to those of MS, including lupus erythematosis, Sjogrens, vitamin and mineral deficiencies, some infections, and rare hereditary diseases.