Because there are no laboratory tests or particular symptoms that definitively point to a diagnosis of MS, confirming the diagnosis can be a complex process. It is not unusual for people to be told they have MS when they actually have something else, or for the diagnosis to be missed in people who actually have MS. Before confirming an MS diagnosis, the doctor must rule out any other condition that could be causing your symptoms, including:
- Infections of the central nervous system (CNS): Lyme disease, syphilis, progressive multifocal leukoencephalopathy (PML), HIV and human T-cell lumphotrophic virus-1 (HTLV-1)
- Inflammatory disorders of the CNS: systemic lupus erythematosus, Sjögren’s syndrome, vasculitis, sarcoidosis and Behçet’s disease
- Genetic disorders: leukodystrophy, hereditary cerebellar degenerations, hereditary myelopathy and mitochondrial disease
- Brain tumors: metastases and lymphoma
- Vitamin B12 deficiency
- Structural damage in the brain or spinal cord: cervical spondylosis, tumor, herniated disc and Chiari’s malformation
- Other non-MS demyelinating diseases: neuromyelitis optica (NMO) and acute disseminated encephalomyelitis (ADEM)
Some of these diagnoses are much rarer than others. Some may be easy to rule out with a simple blood test (e.g. vitamin B12 deficiency), while others, such as sarcoidosis, may require a biopsy. Therefore, it is helpful to work with a physician who is familiar with these conditions and their warning signs so that the appropriate steps can be taken to arrive at a correct diagnosis as quickly as possible. Arriving at the correct diagnosis will enable your doctor to begin the appropriate treatment — whether you have MS or one of these other conditions.