Diagnosis of MS
Diagnosis of MS is based on a detailed history, physical and neurological examination, blood tests, magnetic resonance imaging (MRI scan), spinal tap, and neurological tests.
Blood Tests to Diagnose MS
Blood tests may be used to help rule out other conditions that cause similar symptoms.
Magnetic Resonance Imaging (MRI Scan) to Diagnose MS
MRI scan uses 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 to Diagnose MS
A spinal tap, also known as a lumbar puncture, is performed to detect oligoclonal bands in 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 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).