Diagnosis
The diagnosis of MS is difficult as there is no definitive clinical or laboratory test for the disease. Symptoms vary widely among patients and the same symptoms may be duplicated in other diseases. A successful diagnosis can only be made after many different types of evidence have been assembled, sifted, assessed and interpreted.
A careful study and assessment of the patient's medical history and presenting symptoms is thus necessary, supplemented by findings following clinical examination and the results of imaging tests such as MRI to evaluate the extent of physical damage to the CNS. Analysis of cerebrospinal fluid (CSF) and assessment of conductance in visual and auditory nerve pathways may also be used to support the diagnosis, but there is no single definitive laboratory test.
Rarely, MS may start dramatically with paralysis or loss of vision, in which case a visit to a doctor is usually made relatively urgently and the diagnosis is facilitated. It is more common, however, for MS to start with one or more milder symptoms, which may be intermittent. Most frequently, for instance, patients initially present with disturbed vision, balance difficulties and sensory or motor disturbances. In these cases making the diagnosis can be a lengthy, scrupulous process, and the condition may not be identified until several other symptoms/attacks have occurred. This can take months or even years.