Diagnosis of MS is based on a detailed history, physical andneurological examination, blood tests, magnetic resonance imaging (MRI scan), spinal tap, and neurological tests.
Blood tests Blood tests may be used to help rule outother conditionsthat cause similar symptoms.
Magnetic resonance imaging(MRI scan) MRI scanuses a magnetic field to create detailed images of the brain and spinal cord. This imaging test can be used to detect lesions in the white matter of the brain.
Spinal Tap A spinal tap, also known as a lumbar puncture, is performed to detect oligoclonal bandsin cerebrospinal fluid. Oligoclonal bands result from elevated levels of the antibody immunoglobulin G (IgG) and myelin basic protein, which is a byproduct of demyelination, and are present in more than 85% of MS cases. In this procedure, a needle is inserted between two lower spine (lumbar) vertebrae and cerebrospinal fluid is collected and analyzed.
Evoked Potential Tests Evoked potentials are electrical signals generated by the nervous system in response to stimuli. Evoked potential tests (i.e., somatosensory evoked potentials, visual evoked potentials, brainstem auditory evoked potentials) are performed to evaluate sensory, visual, and auditory functions and detect slowed nerve impulse conduction caused by demyelination.
In these tests, nerves responsible for each type of function are stimulated electronically and responses are recorded using electrodes placed over the CNS (brain and spine) and peripheral nerves (e.g., median nerve in the wrist, peroneal nerve in the knee).
Early signs of MS are often mistaken for other disorders, including the following: