Scenario: A 24-year-old graduate student was studying late at night for an examination when he realized that his left arm and left leg were numb. He dismissed the complaint, recalling that 6 or 7 months ago he had similar symptoms. He rose from his desk and noticed that he had poor balance. His vision was blurred, and remembered that he had some blurred vision approximately 1 to 2 years earlier, but that this resolved. He had not seen a physician for any of these previous symptoms. He went to bed and decided that he would seek medical consultation the next day.

Question: What are the definitive tests to use to identify multiple sclerosis and differentiate it from other differential diagnoses, including other demyelinating nerve disorders?

Potential answers:

1. Spinal tap and ophthalmologic tests
2. A specific set of blood and urine tests only
3. MRI and blood tests
4. Exploratory surgery

Answer with rationale: MRI and blood tests.

An MRI with gadolinium of the central nervous system can show current inflammatory lesions. This test is not accurate for identifying past lesions. A minimum of 2 lesions must be identified for diagnosis.

Blood tests for elevated gamma globulin can also rule in MS. This is due to the proliferation of B cells throughout the CNS. These gamma globulin levels can lead to the presence of oligoclonal bands in the CSF later on, which can be another positive diagnosis indicator.

Other tests can help rule out alternative differential diagnoses, but none specifically rule in MS.

For more information see Chapter 95 Multiple Sclerosis in The Color Atlas of Physical Therapy